News Bulletins and Alerts - Bridgend Astronomical Society

Here is the latest round-up of news from the Society for Popular
Astronomy. The SPA is Britain's liveliest astronomical society, with
members all over the world. We accept subscription payments online
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or renew via a secure server or just see how much we have to offer by
visiting http://www.popastro.com/

PERSEIDS 2010
By Alastair McBeath, SPA Meteor Section Director

Data from the Perseid meteor shower has continued to pour in since
the very early report in ENB 293, both to the SPA and the
International Meteor Organization (IMO). Even those observers
who were clouded-out near the maximum, but who were able to
observe at other times instead, seemed to have enjoyed whatever
view of the Perseids they managed. Results are still preliminary at
this stage. However the IMO's "live" Perseids webpage, giving an
overview of what meteor watchers across the world recorded
(at http://www.imo.net/live/perseids2010/ ), has indicated Zenithal
Hourly Rates (ZHRs) were roughly 60 to 100 from about 16h UT
on August 12 through to ~21h UT on the 13th. Several potentially
stronger phases were apparent within this lengthy spell, though it is
uncertain how significant these may have been as yet. One
particularly interesting period was near 17h-18h UT on August 12,
when ZHRs seemed to have peaked briefly at ~130 +/- 10. Part
of this interval was only a little after the predicted possible encounter
with Comet 109P/Swift-Tuttle's 1479 AD dust trail, parent comet
to the Perseid shower, around 16:50 UT that day. It was believed
the Earth might only skim the outer part of this trail however, and it
is not clear what role, if any, the expectations of the observers may
have had on the claimed activity. For example, early European
radio meteor results reaching the SPA showed no good indication
that anything unusual had occurred at this time. The Perseid radiant
however, while circumpolar for many mid-northern hemisphere
locations, was at about its lowest for the day from Europe then, so
this is not conclusive.

Just over 2800 Perseids have been reported to the Meteor Section
during August now, most from the ten-day spell beginning on August
7-8. Regrettably, many observers struggled with unhelpful sky-
conditions on the critical August 12-13, in Britain and elsewhere in
the world, so a better picture has emerged of how ZHRs behaved
rising before and falling after the maximum than on that night itself.
Despite this, ZHRs (compiled from skies where the limiting
magnitude - LM - was +5.5 or better, cloud cover was less than
20%, and where the radiant was above 25° elevation) from 21h-
08h UT on August 12-13 averaged ~70-110 in the SPA analysis.
Weather problems also reduced the number of meteors available
for the magnitude analysis, albeit the quantity of meteors still allowed
a useful degree of validity to the results. Mean magnitudes,
corrected to an LM +6.5 sky, were +2.4 for the Perseids (776
meteors) and +3.4 for the sporadics (252), both values quite typical.
Too few trained meteor details were provided to allow an analysis of
them this time, though colloquial comments indicated a good
percentage of Perseids left persistent trains, largely as expected.

Also as usual, numerous fireballs (meteors of magnitude -3 or
brighter), mostly Perseids, were reported across the shower's
maximum, but one on August 12-13 at 21:43 +/- 1 minute UT
seemed to have been especially impressive, perhaps peaking
between magnitudes -8 to -12. It was spotted from probably four
locations in central-southern England, two of which sightings were
mentioned on the SPA's Observing Forum "Perseids 2010" topic
(beginning at http://snipurl.com/10nill ), those made by "@@"
(posting timed at 22:13 BST on August 12 - note the automatic
time-stamps appeared to be inaccurate compared to actual clock
time) and "UtopiaPlanitia" (22:51 BST also on the 12th). The
details currently available cannot confirm all definitely saw the same
meteor, but assuming they did would suggest the meteor likely flew
high above the north-Northamptonshire/Cambridgeshire area, or
points adjacent. Another spectacular object was spotted at 00:32
UT on August 12-13 by Karl Antier in Provence, southern France,
despite clouds so thick he could barely see Jupiter at times. Luckily,
one of his colleagues some distance away had better conditions at
the essential moment, and by-chance, managed to image this event.
See: http://snipurl.com/10uabf .

Back in the UK, looking at the distribution of the more fortunate
SPA observers showed southern Britain, approximately bounded to
the north by a line from south Wales through the West Midlands to
the Wash, enjoyed the better conditions on August 10-11, 11-12
and 12-13, though a few spots in Northern Ireland, central-southern
Scotland and near Dundee on the east Scottish coast, enjoyed
some breaks at times on August 12-13 too. Elsewhere, the clearer
skies favoured nights further from the peak. Several observers took
advantage of the holidays to venture to darker-sky sites, with those
travelling to East Anglia and southwest England enjoying the greatest
success, including contributors to the Perseid topics on the SPA's
and UK Weather World's Space Weather Forums (the latter
beginning at http://snipurl.com/10nime ). Similarly, colleagues in
North America and France found taking to the road beneficial in the
hunt for clearer weather. Perhaps the most intrepid was the group
with Richard Kramer, who, over two days, drove and walked to
the summit of Saddleback Mountain (1255 metres/4116 feet) near
the Rangely Lakes region of western Maine in the NE USA for the
shower's maximum night - and better still, they enjoyed some
clearer weather for a time when they got there! His report of their
adventure, with those of lots more, can be read on the Meteorobs
website, http://www.meteorobs.org .

The list of observers to report to us so far was as follows, comprising
quite casual viewers, through to dedicated meteors watchers.
Unmarked contributors, or those with "+ V", provided visual results,
"R" means radio data were presented, and "I" imaging observations.
Many details were taken from the two Forum topics mentioned
above, and more were kindly provided by its leader Mark Davis
from the North American Meteor Network (NAMN; see
http://www.namnmeteors.org). To everyone below, very many
thanks and a hearty "Well Done" for your efforts!

Michael Adams (England), Salvador Aguirre (Nevada, USA;
NAMN), "akkan" (England), Sandy Allan (Scotland), Chris Alder
(England), "andyT" (Wales), Karl Antier (France), "@@" (England),
Tom Banks (England), "billden" (England), Nigel Bolton (England),
Michael Boschat (Nova Scotia, Canada; NAMN; I, R + V), Pat
Branch (Texas, USA; NAMN), "Bushy" (England), Michael Catlin
(North Yorkshire; NAMN), "Charles" (England), "ChaserUK"
(Channel Islands), "Cliff" (England; I + V), "coldfieldboundary"
(Belgium), Tibor Csorgei (Slovakia; NAMN), Amanda Davies &
husband (Wales), Mark Davis & daughter (South Carolina, USA;
NAMN), Paul Domaille (Channel Islands), David Entwistle
(England; R), Lorraine Evans (England), Mike Feist (England),
George Gliba (West Virginia, USA; NAMN), Bill Godley
(Oklahoma, USA; NAMN), "Godot" (England; I + V), Shelagh
Godwin (England), Bill Haddon (California, USA), Dave Hancox
(Scotland; I + V), Alan Heath (England; R), "HippyChippy"
(England), Ken Hodonsky (Nebraska, USA; NAMN), "Jamie
d" & fiancée (England), "Jane B" (England; I + V), "JohnF"
(England), Sam Jowett (England), Richard Kramer & colleagues
(Maine, USA; NAMN), "Lawrie" (location unstated),
"Lightningfox92" (England), "louise79" (Northern Ireland), Tony
Markham (England), Pierre Martin (Ontario, Canada; NAMN),
Paul Martsching (Iowa, USA; NAMN), Kenneth Meadows
(England), Peter Meadows (England; I), "Miguella" (England), Jane
Mills (England), Koen Miskotte (France; NAMN), "Naplesnut"
(England), David Oesper (Texas, USA; NAMN), Don Olson &
colleagues (Texas, USA), Kenneth Pamment (England), "pettinger"
(England), Robin Scagell (England; I + V), "Scoggy" (England),
Pete Scott (England; I + V), "scrapemedic" (England), Jason Smith
(England), "snow hope" (Northern Ireland), Chris Stephen (Florida,
USA; NAMN), R Stevenson (England), Rich Taibi (Maryland &
West Virginia, USA; NAMN), "tcmorris78" (Scotland), István
Tepliczky (Hungary; NAMN), Harold Tinker (Ohio, USA), Peter
Upton (England), "UtopiaPlanitia" (England), "Vadno581" &
daughters (Scotland), "vincentnm" (location unstated; I), Colin
Watling (England), William Watson (Ontario, Canada, New York
& Pennsylvania, USA; NAMN), "Winso" (England), "WSM-
Weather" (England), and the Director (England).

All further observations would be most welcome!

ADDITIONAL AUGUST FIREBALLS
By Alastair McBeath, SPA Meteor Section Director

Apart from those fireballs noted already, and as discussed last time,
two more from the first half of August have been recorded now from
more than one location. August 4-5, around 22:00 UT brought a
very bright, long-pathed, slow-moving fireball for lucky witnesses at
sites in Hampshire and the West Midlands. Then on August 10-11,
within about eight minutes of 22:07 UT, a magnitude -4/-7 possible
Alpha Capricornid fireball was seen from four locations in London,
Berkshire, Buckinghamshire and Wrexham. Little other information
has been deduced for either object as yet, unfortunately.

Fireball observations made from places in the British Isles or nearby
are always welcomed by the Meteor Section. For advice on what
details to submit (including an e-mail report form), see the "Making
and Reporting Fireball Observations" page of the SPA website, at:
http://snipurl.com/u8aer .

PLANETS
By Andrew Robertson, SPA Planetary Section Director

As Jupiter is coming to prominence (reaches opposition on September
21) I'm now starting to get more observational reports from members.
A selection of them can be viewed at http://snipurl.com/xc9r8 .

The SEB is still faded but the GRS is very red. Oval BA is near the
GRS, as can be seen in the excellent image taken by SPA member Simon
Kidd: http://snipurl.com/10tbua . I had a good view of it in the
early hours of August 24. But you don't need expensive or exotic
equipment to enjoy observing the planets -- look at this sketch made
by Cliff Meredith using a 60-mm spotting 'scope that he bought from
Aldi's: http://snipurl.com/10tckw .

There is a conjunction of Jupiter and Uranus during September,
providing an opportunity to observe both planets in the same field of
view. Between 12th and 26th they are a degree or less apart, closest
approach being on September 18/19 when Uranus is just 50' north of
Jupiter. At the moment Uranus, which like Jupiter comes to opposition
on September 21, lies 2 degrees to the west of Jupiter and is moving
slowly westwards, but not as quickly as Jupiter. Of course all the
outer planets exhibit retrograde motion near opposition as the Earth
'overtakes' them, but the nearer ones show faster angular motion than
the more distant ones, so Jupiter will 'overtake' Uranus while both
are in the phase of retrograde motion. In fact they are both
reversing across the equinoctial colure about now -- Uranus crossed it
on August 25 and Jupiter will do so on September 14.

Neptune came to opposition on August 20. About that date it moved
back from Aquarius into Capricornus; it is not favourably placed for
observation from the British Isles, having been south of the equator
for almost as long as anyone can remember, but younger members need
not despair, as it is gradually moving north now and will reach the
equator in about 15 years' time and Gemini in about 55 years!

There is a favourable morning apparition of Mercury from mid-
September, Greatest Elongation West (18 degrees) being on the 19th.

Any reports of observations would be most welcome via:
http://popastro.com/planet/contact/

TROJAN ASTEROID FOUND NEAR NEPTUNE
Subaru Telescope facility, Hawaii

Astronomers using the 8.2-m Subaru Telescope in Hawaii have discovered
the first Neptune Trojan asteroid, 2008 LC18, to be found near
Neptune's L5 Lagrangian point L5. Lagrangian points are five places
in space where the gravitational forces from two bodies of very
unequal mass, such as the Sun and a planet, are in balance such that
small bodies like asteroids can remain more or less fixed with respect
to the planet. The Lagrangian points L1, L2, and L3, which are
points along the direct line drawn through the two main bodies, are
unstable, so a slight displacement of an object there may result in
its permanent departure. The other points, L4 and L5, 60° ahead of
and behind the planet, are stable, so dust grains and other objects
remain in the vicinity and tend to collect there. Trojans share their
planet's orbit, but they do not collide with the planet because they
stay safely near the Lagrangian point ahead of or behind it. Neptune
was already known to be accompanied by six Trojan asteroids, but they
are all near the L4 point. It is more difficult to discover them near
L5, because that point is currently in Sagittarius, in a very rich
Milky-Way star field nearly in the line of sight to the Galactic
Centre. It is estimated that the 'new' Neptune Trojan has a diameter
of about 100 km.

RICHEST PLANETARY SYSTEM DISCOVERED
ESO

Astronomers have discovered a planetary system containing at least
five planets. They used the HARPS spectrograph, attached to ESO's
3.6-m telescope at La Silla, Chile, for a six-year study of the
Sun-like star HD 10180, located about 40 parsecs away in the southern
constellation Hydrus. From the 190 individual HARPS measurements, the
astronomers detected the tiny back and forth motions of the star
caused by the complex gravitational attractions from five or more
planets. The five strongest signals correspond to planets with
Neptune-like masses -- between 13 and 25 Earth masses -- which orbit
the star with periods ranging from about 6 to 600 days. They are
between 0.06 and 1.4 AU (Astronomical Units or Earth--Sun distances)
from their central star. There may be other planets present in the
system, but the evidence is inconclusive.

The newly discovered system of planets around HD 10180 differs from
the Solar System inasmuch as it has five Neptune-like planets all
lying within a distance equivalent to the orbit of Mars, but no
Jupiter-like giant. All the planets seem to have almost circular
orbits. So far, astronomers know of fifteen systems with at least
three planets. Using the new discovery as well as data for other
planetary systems, the astronomers found an equivalent of the
Titius-Bode law that exists in our Solar System: the distances of the
planets from their star seem to follow a regular pattern. Another
result found by astronomers studying such systems is that massive
planetary systems are found around relatively massive and metal-rich
stars, while the four lowest-mass systems belong to lower-mass and
metal-poor stars. Theoreticians have tried to develop models that
mimic that property.

'CITIZEN SCIENTISTS' DISCOVER NEW PULSAR
University of Wisconsin

Einstein@Home, based at the University of Wisconsin at Milwaukee and
at the Max-Planck-Institute in Germany, is a project that enlists the
aid of 250,000 volunteers from 192 countries, who donate time from
their home and office computers to search for signals from radio
pulsars in observations from Arecibo, the world's largest and most
sensitive radio telescope. More than a year after the project
started, the first deep-space discovery has been made by it, when
three lay people -- a German and an American couple -- have discovered
a new radio pulsar. The object, PSR J2007+2722, is a neutron star
that rotates 41 times per second. It is in the Milky Way, about 5000
parsecs away in the constellation Vulpecula. Unlike many pulsars that
spin as quickly and steadily, PSR J2007+2722 sits alone in space, and
has no orbiting companion star. Astronomers think it may be a
'recycled' pulsar that has lost its companion, but they can't rule
out that it may be a young pulsar born with a lower-than-usual
magnetic field.

GAMMA-RAY NOVA DISCOVERED
Space.com

A nova is a thermonuclear explosion on the surface of a white-dwarf
star. It is fuelled by hydrogen transferred from a companion star.
Novae emit X-rays, but until now they have not been known to emit
gamma-rays, a still more energetic form of radiation. Now researchers
using the orbiting Fermi telescope have discovered gamma-rays from a
nova called V407 Cygni, some 2700 parsecs away. It is a binary system
which consists of a white dwarf and a pulsating red giant. The
gamma-rays came after a nova explosion in the system, spotted by
Japanese amateur astronomers in March, which at its peak was just
below the level of naked-eye visibility, brighter than at any other
time in the 70-odd years that the system has been under observation.
The researchers suggest that the gamma-rays were generated when the
blast waves from the nova collided with the dense wind from the red
giant.

In most novae, the white dwarf's companion is a normal main-sequence
star, whose stellar wind is light compared with that of the red giant
in V407 Cygni, so there is far less material with which to generate
gamma-rays. Very few binary systems combine the kind of white-dwarf
stars that give rise to novae with red giant companions, so gamma-ray
novae are probably quite rare.

ACTIVE STAR FORMATION IN DISTANT CLUSTER OF GALAXIES
Texas A&M University

Images obtained with the Spitzer space telescope of an early, distant,
cluster of galaxies have revealed that a significant fraction of those
ancient galaxies were still actively forming stars. The images looked
back in time nearly 10 billion years at a high-redshift cluster known
as CLG J02182-05102. The cluster is 'modern' in its appearance and
size despite being observed 'only' 4 billion years after the Big Bang,
and is seen to be producing hundreds to thousands of new stars every
year, a higher birth-rate than that in present 'nearby' galaxies.

What is particularly striking is the fact that the stellar birth rate
is higher in the cluster's centre than at its edges, the exact
opposite of what happens in our part of the Universe where the cores
of galaxy clusters are known to be galactic graveyards full of massive
elliptical galaxies composed of old stars. A well-established
hallmark of galaxy evolution in action is how the fraction of
star-forming galaxies decreases with increasing galaxy density. In
other words, there are more star-forming galaxies in the field than in
the crowded cores of galaxy clusters. However, in the old cluster
there are many galaxies with star-formation rates comparable with
those of their cousins in the lower-density field environment.

Owing to holidays the next scheduled edition of the bulletin will be
issued on 26 September 2010.

Bulletin compiled by Clive Down

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PERSEID MAXIMUM - FIRST NEWS
By Alastair McBeath, SPA Meteor Section Director

It is too soon for a definitive overview of the Perseid maximum,
which was expected on August 12-13 (see ENB 292, archived at:
http://snipurl.com/10ncie ). However, early indications are the
shower lived up to expectations for those with clearer skies.
Provisional Zenithal Hourly Rates (ZHRs) on the International Meteor
Organization's (IMO's) "live" Perseid results page (at
http://www.imo.net/live/perseids2010/ ) were around 80-90 during
the UT night of August 12-13, suggesting the peak was probably
fairly normal for recent years. In early August, the IAU circulated a
revised prediction for a possible encounter with the dust trail laid
down by the Perseids' parent comet, 109P/Swift-Tuttle, in 1479,
around 16:50 UT on August 12 (with thanks to SPA Vice-President
Robin Scagell for forwarding details). It was thought likely the Earth
would only skim the outer fringes of this trail, so its potential effect
on Perseid activity was unclear. The IMO results page had no data
covering this interval when I wrote these notes. Hopefully a more
detailed examination of various facets of the peak should be practical
as more results arrive.

Observations and comments reaching the Meteor Section from the
first half of August have indicated typically mixed fortunes for UK
watchers, thanks to another disappointing summer in many places.
Information to-date found Perseid ZHRs of ~5-10 during the first
week of August, rising to ~20-45 between August 9-11, before
increasing smartly closer to the peak, all much as usual, so far as the
limited data allows. There are comments showing how some British
observers fared on the SPA's Observing Forum at:
http://snipurl.com/10nill, and the UK Weather World's Space
Weather Forum at: http://snipurl.com/10nime, which also has a few
photos. From these, its seems southern England may have had the
better conditions on August 12-13. Northeast England was overcast
with heavy rain driving-in on a strong north to northeaster then
certainly. All further results would be most welcome!

LATE JULY RADIO METEOR ACTIVITY
By Alastair McBeath, SPA Meteor Section Director

Full Moon in late July combined with generally poor weather then
meant no visual results were secured covering the late July Delta
Aquarid and Alpha Capricornid maxima. Fortunately, the arrival of
July's Radio Meteor Observation Bulletin (No. 204; see
http://www.rmob.org ), provided promptly as ever by its Editor
Chris Steyaert, has allowed an investigation of what likely happened
then as detected by forward-scatter radio equipment. The observers
involved included: Enric Algeciras (Spain), Michael Boschat (Nova
Scotia, Canada), Jeff Brower (British Columbia, Canada; Jeff
provided additional information directly to us as well), Willy Camps
(Belgium), Gaspard De Wilde (Belgium), Franky Dubois (Belgium),
Kurt Fisher (Utah, USA), Karl-Heinz Gansel (Germany), Mike Otte
(Illinois, USA), Steve Roush (Arizona, USA), Andy Smith (England),
Chris Steyaert (Belgium), Dave Swan (England), Maarten
Vanleenhove (Belgium), Felix Verbelen (Belgium). Some observers
were on holiday, and quite a few struggled with continued
summertime interference problems, so there were fewer data than
might have been hoped, but the surviving results gave a reasonably
clear signature for heightened radio meteor rates overnight, when the
Delta Aquarid and Alpha Capricornid radiants were above the
horizon, from July 28 to 30 inclusive. The most convincing peaks
were on July 29 and 30, that on the 30th marginally the stronger, so
likely indicating when both showers were at their most active. The
radiants were too close together for radio to define the sources
separately, but with recent IMO results suggesting both showers
may peak on July 30 anyway, this does imply that may have been the
case this year.

BETA TAURIDS UPDATE
By Alastair McBeath, SPA Meteor Section Director

As discussed in ENB 292, the daytime Beta Taurid meteor shower
maximum probably happened around June 25 and 26, while echo-
counts seemed to have picked-up again around June 30, from a
source in the daytime sky that was plausibly also the Beta Taurids.
RMOB 204 has allowed a check on what took place in early July as
well. Aside from most of the radio observers already listed above, a
sufficiently complete dataset was also available during the first week
of the month to examine for this source from Johan Coussens in
Belgium. After the slightly increased activity on June 30, this
dropped on July 1, but then rose to a daytime peak on July 2
apparently only a little less in strength than those on June 25-26
(albeit confirmed by fewer radio-meteor systems). Activity remained
elevated, if at a lower level, on July 3, before returning back to its
more "normal" regime. Such a peak in early July has not often been
recorded so clearly in previous Section analyses since 1994, but
whether this represented an unusual Beta Taurid return, or simply
reflected the fact observers were lucky with conditions during the
key interval, is uncertain. An interesting result whatever the case.

RECENT FIREBALLS
By Alastair McBeath, SPA Meteor Section Director

Aside from another fine crop of Perseid fireballs in the last few days,
several multiply-observed fireballs have been reported from Britain
since mid July.

July 13-14 brought two bright events, one around 20:30 UT as seen
from Guernsey, the other of magnitude -9 or so at about 21:00,
witnessed from Kent, Somerset and Wiltshire. Though there were
similarities between them, and some uncertainty in their timings, it is
probable these two were separate fireballs. That seen from Guernsey
was likely high above the Channel, perhaps above the western part
of Lyme Bay, or possibly the adjacent parts of Devon. The ~21h
event too may have happened over the Channel, probably off or over
the Dorset coast. It may have been travelling in a direction between
roughly E-W to SE-NW, and its path likely fell within about 60 km
of a point above the sea ~10-20 km south of Lulworth Cove, Dorset.
Its start altitude could have been ~115 +/- 10 km, but the end was
too poorly-constrained to suggest a more plausible height range.

On July 18-19 at 22:16 UT, a fireball estimated as brighter than
magnitude -5 was seen from two separate sites in Suffolk. It was also
imaged by Klaas Jobse's automated all-sky camera system at
Oostkapelle in the Netherlands, part of the European Fireball
Network of stations. The image is quite faint, but can be seen at
http://snipurl.com/10o55r , with an enlarged inset showing the
meteor's trail in more detail at: http://snipurl.com/10o56o . It has not
been possible to estimate a probable trajectory for the event as yet,
but its path may have lain high above the southern North Sea
somewhere between the Netherlands and East Anglia.

August 7-8, 21:40 UT, brought a magnitude -5/-6 fireball for lucky
observers in Wiltshire and Oxfordshire, while August 10-11
produced a magnitude -4/-7 possible Alpha Capricornid fireball
within five minutes of 22:05 UT for three witnesses in
Buckinghamshire, Berkshire and London. No details on the
trajectories for either have been established so far.

Notes on other UK-seen fireballs reported to the Section, apart from
Perseids close to their peak, can be found on the "Recent Fireball
Sightings" webpage, at: http://snipurl.com/w9p6d, while additional
sightings of the above, or other, fireballs, made from the British Isles
and nearby, would be welcomed. The minimum details required are:

1) Exactly where you were (give the name of the nearest town or
large village and county if in Britain, or your geographic latitude and
longitude if elsewhere in the world);

2) The date and timing of the event in UT (remember to subtract one
hour from current clock time, BST, to get UT); and

3) Where the fireball started and ended in the sky, as accurately as
possible, or where the first and last points you could see of the trail
were if you did not see the whole flight.

More advice and a fuller set of information to send (including an
e-mail report form) are on the "Making and Reporting Fireball
Observations" page of the SPA website, at: http://snipurl.com/u8aer .

And finally... You may have spotted items in the press or online about
a supposed meteorite fall at a county cricket match at Uxbridge in
late July, narrowly missing a couple of spectators. Sadly,
investigations quickly revealed it to have been simply a small lump
of cement, dropped either from an aircraft's wheel, or perhaps by a
bird. The media were not quite so eager to report this reality,
however. For further details and links to the online sources, see
the SPA's General Chat Forum topic at: http://snipurl.com/10o576 .

PLANETS
By Andrew Robertson, SPA Planetary Section Director

Jupiter is now coming to the fore -- at the beginning of August it was
at a healthy 30 degrees altitude by 2am BST, and I'm now starting to
receive observations of it. Jupiter is very much the planet 'in
season' and I would encourage observations from now as it approaches
opposition on September 21. I prefer to observe the planets before
opposition when they are at their highest in the early hours when
seeing is normally better although I appreciate that not everyone is
in a position to do that. The SEB (South equatorial belt) is still
faded but could burst into activity at any time. The GRS (Great Red
Spot) is a very prominent red. I had a good view of it, made even
more prominent by the absence of the SEB, in the early hours of August
12.

Venus reaches Greatest Elongation (East) on August 20, after which it
will start displaying a crescent phase. As its phase gets narrower
its angular diameter increases. On August 15 Venus is low down in the
WSW at an altitude of only 9 degrees just after sunset. It's worth
observing Venus at this time -- especially looking out for the moment
of apparent half-phase (dichotomy). At evening elongations that
normally occurs around 5 days earlier than geometry would lead one to
expect.

I post a selection of members' observations on the SPA web site;
they can be viewed on the Planetary Section's web page at
http://snipurl.com/xc9r8 .

Any reports of observations would be most welcome via
http://popastro.com/planet/contact/

NEW REVELATIONS ABOUT MERCURY
Carnegie Institute

Analysis of data from Messenger's third and final fly-by of Mercury
last September has found evidence of later vulcanism than had
previously been recognized, new magnetic information, and the first
observations of emission from an ionized species in Mercury's very
thin atmosphere or exosphere. During its first two fly-bys of
Mercury, Messenger captured images showing that pervasive vulcanism
occurred early in the planet's history. The third fly-by revealed a
290-km-diameter impact basin, among the youngest basins yet seen and
recently named Rachmaninoff, having an inner floor filled with
spectrally distinct smooth plains.

The sparsely cratered Rachmaninoff plains post-date the formation
of the basin and apparently formed from material that once flowed
across the surface. Astronomers interpret these plains to be the
youngest volcanic deposits yet found on Mercury. Moreover, an
irregular depression surrounded by a diffuse halo of bright material
northeast of the basin marks a candidate explosive volcanic vent
larger than any previously identified on Mercury. These observations
suggest that vulcanism on the planet lasted a lot longerthan had been
thought.

During the fly-by, the magnetometer documented for the first time a
build-up of magnetic energy in Mercury's magnetic tail. The increases
in energy in Mercury's the tail were large (factors of two to three),
and they occurred very quickly, lasting only two or three minutes from
beginning to end. The increases in tail magnetic energy at Mercury
are about 10 times greater than at the Earth, and the events run their
course about 50 times more rapidly.

Observations were also made of emission from ionized calcium in
Mercury's exosphere. The emission was concentrated over a relatively
small area one to two Mercury radii anti-sunward of the planet, with
most of the emission occurring close to the equatorial plane. The
concentrated distribution cannot be explained by in-situ conversion of
local calcium atoms to calcium ions and instead points to
magnetospheric transport of the ions as a mechanism for concentrating
them. Although such transport is common in planetary magnetospheres,
the degree to which it can affect the distribution of species in
Mercury's exosphere was not fully appreciated.

POTENTIALLY HAZARDOUS ASTEROID
Science Daily

A lot of interest has been shown in recent years in 'potentially
hazardous asteroids', which might at some future time hit the Earth,
although so far none of any significant size has been found to have
any but an infinitesinal chance (which reduces more and more as
observations accumulate) of an actual impact.

Asteroid (101955) 1999 RQ36 is such an object. It was discovered in
1999 and is around 560 metres across. Its orbit is actually well
determined by 290 optical observations and 13 radar measurements, but
there is a significant uncertainty in extrapolating it into the far
future because the paths of small asteroids are slightly influenced by
the Yarkovsky effect. That effect arises on a rotating body because
the 'afternoon' side of the body is warmer than the morning side,
having been in sunshine longer, so it radiates more, and the infrared
photons that constitute its radiation carry away a certain amount of
momentum. By the law of conservation of momentum, that has to be
balanced by momentum imparted to the asteroid in the opposite
direction, that is, 'downwards' from the point of view of the evening
hemisphere.

Spanish scientists have published a paper in the journal 'Icarus',
showing that there is a tiny possibility that the relevant asteroid
could collide with the Earth in 2182. They give reasons for saying
that, if it were wished to try to modify the path of the asteroid by
artificial means to make it even more certain that it will miss the
Earth, it would be much less difficult and expensive to do so before
2060. Although of course even a small asteroid has what is by
ordinary standards an enormous mass, so it would not be accelerated
much by forces of ordinary magnitude, a very slight change in velocity
accumulates to a large distance in the course of a hundred years.

BROWN DWARF ORBITING YOUNG SUN-LIKE STAR
University of Arizona

An international team of astronomers using the 8-m Gemini-South
telescope in Chile has discovered a 36-Jupiter-mass brown-dwarf
companion to the star PZ Tel, which is an object quite like the Sun
but very young -- about 12 million years old. The team used an
adaptive-optics system coupled to a coronagraph in their efforts to
detect faint objects close to bright ones. The companion is 18
astronomical units (Earth--Sun distances) from the primary star,
subtending a third of a second of arc at the distance of PZ Tel.
Because PZ Tel is a rare type of object, being both close and very
young, it has been imaged several times in the past, so astronomers
were surprised to see a companion around what was thought to be a
single star. The orbit appears to be eccentric, such that in the past
the angular separation of the system has been smaller and the
companion's image has been lost in the glare of the primary's.

ASTRONOMERS FIND VERY MASSIVE STAR
RAS

A UK-led international team of astronomers has discovered the most
massive stars to date, including one which they think at birth had
more than 300 times the mass of the Sun, well above the currently
accepted limit. The astronomers studied two young clusters of stars,
NGC 3603 and RMC 136a. NGC 3603 is 22 000 light-years away;
RMC 136a is located inside the Tarantula Nebula, in one of our
neighbouring galaxies, the Large Magellanic Cloud, 165 000 light-
years away.

The team found several stars with surface temperatures over 40 000
degrees and luminosities several million times as great as the Sun's.
Comparisons with models seem to imply that the stars were born with
masses in excess of 150 solar masses. One of them, in the R136
cluster, is proposed to be the most massive star ever found -- to have
a current mass of about 265 solar masses and a birth mass of as much
as 320 times that of the Sun. But that is only estimated from
computer models. In NGC 3603, the astronomers could determine
directly from the orbital parameters the masses of two stars that
belong to a double-star system. Three objects in the cluster have
estimated masses at birth above or close to 150 solar masses, but one
of them is double, with an orbital period of 3.77 days. The two stars
in that system are 120 and 92 times the mass of the Sun.

HOT EXOPLANET WITH COMET-LIKE TAIL
NASA

Astronomers using the Cosmic Origins Spectrograph (COS) on the Hubble
telescope have confirmed the existence of an object that could be
called a "cometary planet". The gas-giant planet, named HD 209458b,
is orbiting close to its star and its heated atmosphere is
escaping into space. The planet is slightly less massive than Jupiter
but orbits 100 times closer to its star in a period of just over three
days. It has been intensely scrutinized because it is one of the few
extra-solar planets that transit their respective stars. During a
transit, astronomers may be able to study the structure and chemical
makeup of the planet's atmosphere by observing the starlight that
passes through it. Hubble detected carbon and silicon in the planet's
1100°C atmosphere. The detection showed that the parent star is
heating the entire atmosphere, dredging up the heavier elements and
allowing them to escape from the planet. The data also showed that
the material leaving the planet was not all travelling at the same
speed. Some gas was found to be escaping at high velocities, with a
large amount flowing toward us at 10 km/s. The most likely
interpretation is that the gas is being swept up by the stellar wind
to form a comet-like tail trailing the planet.

UNUSUAL COSMIC LENS
ScienceDaily

Astronomers have discovered the first known case of a distant
galaxy being magnified by a quasar acting as a gravitational lens.
The first gravitational lens was discovered in 1979, and produced an
image of a distant quasar that was magnified and split by a
foreground galaxy. Hundreds of cases of gravitationally lensed
quasars are now known. But, until the current work, the reverse
process -- a background galaxy being lensed by the massive host
galaxy of a foreground quasar -- had never been detected.

Quasars, which are extraordinarily luminous objects in the distant
Universe, are thought to be powered by super-massive black holes
in the cores of galaxies. A single quasar can be a thousand times
brighter than an entire galaxy of a hundred billion stars, which
makes studies of their host galaxies very difficult. The
researchers say that the significance of the discovery is that it
may provide a way to understand such host galaxies.

RECORD-BREAKING X-RAY BLAST
Penn State University

A blast of the brightest X-rays ever detected from beyond our Milky
Way Galaxy's neighbourhood temporarily blinded the X-ray eye on the
Swift space observatory earlier this summer. The X-rays travelled
through space for 5 billion years before overwhelming Swift's X-ray
telescope on June 21. The blindingly bright blast, named GRB 100621A,
came from a gamma-ray burst, a violent eruption of energy thought to
come from the explosion of a massive star turning into a new black
hole. It was by far the brightest source ever seen in X-ray
wavelengths at cosmological distances.

Gamma-ray bursts typically begin with a bright flash of high-energy
gamma-rays and X-rays, and then fade away, sometimes leaving
behind a rapidly declining afterglow in less-energetic wavelengths,
including optical and ultraviolet. Surprisingly, although the energy
from the June burst was the brightest ever in X-rays, it was merely
ordinary in optical and ultraviolet wavelengths. The Swift scientists
were able to estimate the overall brightness of GRB 100621A by
sampling the photons at some distance from its overexposed centre
and using a standard correction technique.

JAPAN TO LAUNCH MERCURY MISSION IN 2014
Indiavision News

Japan is preparing to launch a space mission to Mercury in 2014, using
a craft covered in mirrors to reflect the 450°C heat from the planet.
According to the Japan Aerospace Exploration Agency, the mirrors will
help the probe to survive temperatures on the surface of the planet.
Scientists have calculated that, by reflecting the intense heat of the
Sun, the temperature of the mirrors can be kept at about 160°C.
Inside the body of the spacecraft, where the observation equipment
will be housed, temperatures should be below 60°C. The craft stands
around six feet high and is powered partly by solar energy collected
by panels that are wrapped around its body. It is designed constantly
to rotate to prevent one side becoming too hot. JAXA scientists hope
to be ready to launch the probe -- which is at present unnamed -- in
2014. JAXA has been boosted by the impressive performance of
Hayabusa, which returned to Earth in June after a seven-year journey
to recover particles of an asteroid, and Ikaros, which was launched in
May and is the first spacecraft to draw its energy from a solar-
powered sail.

Bulletin compiled by Clive Down

JUNE BOÖTIDS - FURTHER DETAILS
By Alastair McBeath, SPA Meteor Section Director

It has remained unclear whether any significant June Boötid activity
occurred on June 23-24, as had been predicted in advance, further
to the preliminary discussion given last time. An examination of the
results reaching the Meteor Section directly, coupled with
observations reported on the IMO-News and Meteorobs e-mailing
lists, has suggested that Zenithal Hourly Rates (ZHRs) between
roughly 22h-06h UT on June 23-24 averaged 9 +/- 2, far below
the anticipated ~20-50. Video rates for the shower then averaged
about two sporadics per June Boötid, which while a rather crude
estimated method, did imply quite weak Boötid activity overall.
Radio results provided directly, plus those reported in June's Radio
Meteor Observation Bulletin (RMOB No. 203), showed little sign
of anything unusual on June 23-24, and nothing at all on June 27,
another potential date for June Boötid activity based on previous
years' events (see ENB 290, archived at: http://snipurl.com/zicst .
There was an indication of weak radio-meteor activity potentially
due to the Boötids between ~11h-13h UT on June 23 in some of
the data collected by observers in North America (European
observers had no suitable radiant elevation for the shower then).
Unfortunately, the relatively few sets of radio observations not
affected by summertime Sporadic-E interference (on which see
also ENB 290), and the paucity of data collected by other
techniques, made these results tentative only. It is though interesting
that none found the kind of easily-detected, sustained rates found
with the shower at both its other recent outbursts, in 2004 and 1998.

The observers whose data was used in preparing this analysis,
including those from the two e-mail lists, RMOB 203 (provided
by Editor Chris Steyaert; available at: http://www.rmob.org ),
and the North American Meteor Network (NAMN; see
http://www.namnmeteors.org ; results and additional discussion
from Network leader Mark Davis) were as follows, where "R"
means radio, "Vi" video and "V" visual results were provided by
that person:

Enric Algeciras (Spain; RMOB; R), Orlando Benitez (Canary
Islands; RMOB; R), Michael Boschat (Nova Scotia, Canada;
RMOB; R), Jeff Brower (British Columbia, Canada; R; some data
also in RMOB), Willy Camps (Belgium; RMOB; R), Johan
Coussens (Belgium; RMOB; R), Gaspard De Wilde (Belgium;
RMOB; R), Kurt Fisher (Utah, USA; RMOB; R), Karl-Heinz
Gansel (Germany; RMOB; R), Patrice Guérin (France; RMOB;
R), Javor Kac & colleagues (Slovenia; Vi + V), Paul Martsching
(Iowa, USA; NAMN; V), Mike Otte (Illinois, USA; RMOB; R),
Jürgen Rendtel (Germany; V), Steve Roush (Arizona, USA;
RMOB; R), Wayne Sanders (British Columbia, Canada; RMOB;
R), Andy Smith (England; RMOB; R), Chris Steyaert (Belgium;
RMOB; R), Enrico Stomeo (Italy; Vi), Dave Swan (England;
RMOB; R), Istvan Tepliczky (Hungary; RMOB; R + Vi), Michel
Vandeputte (Belgium; V), Felix Verbelen (Belgium; RMOB; R).

My grateful thanks go to all involved for their efforts, and also to
Rich Taibi in Maryland, USA, for additional discussions of some
of the early radio results especially. Any further June Boötid
observations would be very welcome still!

JUNE'S DAYTIME METEOR SHOWERS
By Alastair McBeath, SPA Meteor Section Director

Three major, annual showers have maxima due in June, all with
radiants near the Sun, and detectable from Britain only by radio in
the daytime. Details are given each year for them in our June
meteor activity webpage. In general, radio observers have managed
to follow something of them for many years, when summertime
interference has permitted. All three were discovered by radar from
Jodrell Bank in 1947. Theoretically, the Arietids should peak on
June 7, with past estimates implying their equivalent visual ZHRs
could be around 60. Similarly, the Zeta Perseids should reach
maximum on June 9 (visual-equivalent ZHRs ~40). Both these
radiants are so close together in the sky, and their maxima follow
one another so quickly, it is impossible for amateur radio-meteor
systems to separate the two. The final major daytime shower in
June is the Beta Taurids, with an often ill-defined peak around
June 28, best visual-equivalent ZHRs about 25. This is the Earth's
second annual encounter with the Taurid showers we see visually
overnight each year in the autumn. Drawing on extra data provided
by Jeff Brower in Canada, and the observers listed above from
RMOB 203, analyses were carried out to try to establish the more
likely near-maximum activities for all three sources.

A disappointingly large number of European radio datasets were
badly affected by Sporadic-E throughout the first half of June
especially, leading sometimes to entire days'-worth of results being
lost, a great frustration for both observers and analysts.
Consequently, the findings here are not as securely-established as
might be preferred. With that caveat in mind, a generally heightened
level of radio meteor activity was found in the majority of the
surviving results between June 6 and 12, due to daytime activity.
The most probable daylight peaks fell on June 8 and 11 within that
time, but neither was particularly obvious. These more probable
peak dates were in-line with the Section's analyses from previous
years, using results going back to the early 1990s, which have often
indicated the Arietid and Zeta Perseid peaks could be happening
around a day later than predictions suggested (which predictions
were based chiefly on radar results collected sporadically during the
late 1940s to early 1970s).

Gaps in the data created continued difficulties for the Beta Taurid
analysis, though a daylight peak can be inferred as falling between
June 24 and 28, likely due chiefly to this radiant or one nearby.
Within that period, a majority of the systems less-affected by
interference gave a probable peak on June 25 or 26. There were
also indications activity may have been rising again on June 30,
something which will need checking once all July's radio data is
available. As noted already, an ill-defined peak has seemed to be
a feature of the Beta Taurids, and previous examinations have
hinted that there may be more than one possible maximum date in
late June to early July.

Again, my most grateful thanks go to all the observers involved, with
commiserations to those whose data was badly-affected by Sporadic-E.

VERY SLOW FIREBALL IMAGED OVER FRANCE
By Alastair McBeath, SPA Meteor Section Director

An unusually long-lasting, very slow fireball that remained visible for
around 7-10 seconds, occurred over southern France on June 5-6,
at 22:37 UT. It was reported to the Section directly, but French
meteor and fireball analyst Karl Antier received a great many more
reports of it, including news that the event had been caught on video
by the Italian Video Meteor Network. The video record is available
at: http://snipurl.com/zivw5 .

Ordinarily, the SPA Meteor Section collects data chiefly on fireball
events spotted from the British Isles and places nearby, but any
British holidaymakers who were in France at the time and saw this
event are welcome to send-in a full report, if they have not already
provided details to Karl or the Section. Copies of such sightings
will be forwarded to Karl as well, to assist with his analysis. Details
on what to report, including an e-mail fireball report form, can be
found on the "Making and Reporting Fireball Observations"
webpage, at: http://snipurl.com/u8aer .

MAIN METEOR PROSPECTS FOR JULY-AUGUST
By Alastair McBeath, SPA Meteor Section Director

July-August brings one of the stronger near-ecliptic meteor
showers during the year, the Delta Aquarids, whose maximum
ZHRs of about 15-20 are usually achieved for a day or two around
July 28-30. Regrettably, the shower radiant's southerly Declination
(not unexpectedly, it lies near the star Delta Aquarii in late July),
means observed meteor numbers are always much lower than the
ZHRs from Britain, though rare Delta Aquarid meteors can be very
bright at times. Full Moon on July 26 ruins any possibility for
dark-sky coverage of the likely peak from the UK this summer,
though lower activity of these medium-speed meteors is usually
seen from circa July 12 till August 19. For more information and a
radiant chart, see July's meteor activity webpage at:
http://snipurl.com/zjivm .

By contrast, the Perseid maximum fares much better, thanks to new
Moon on August 10. It is due between 18:30 UT on August 12 to
07:00 UT on August 13 this year, most likely at some stage from
about 23:30 to 02:00 UT. It should produce ZHRs of around 100.
This most plausible peak interval is very favourable for Britain, as
the Perseid radiant, a few degrees northeast of the "Double Cluster"
near the maximum, can be usefully-observed from roughly 22h UT
onwards, culminating after dawn. Perseids are swift, often bright,
and commonly trained meteors, and those hoping to image some
may find their capture rates enhanced by aiming towards
And-Cas-Peg-Cyg. The shower is active from July 17 or so
through to August 24, and although rates are always lower away
from the peak, observed activity is usually good to very good for a
couple of days before the maximum plus a day or so afterwards.
This is important to remember if it seems the actual peak night may
be clouded-out. Further information and a Perseid radiant chart is
on the August meteor activity webpage, http://snipurl.com/zjjbd .

Good luck, and clear skies!

PLANETS
By Andrew Robertson, SPA Planetary Section Director

I have had no reports of planetary observations since my last notice,
which is hardly surprising since it doesn't get reasonably dark until
after many people have gone to bed and there haven't been any planets
on prominent display. You can see Venus low in the west after sunset,
and Mars & Saturn as it gets a bit darker, but they're all low down
and don't really offer much detail although they are still nice to see
with the unaided eye and binoculars. On July 30, Mars and Saturn are
in conjunction less than 2 degrees apart, with the much brighter Venus
8 degrees away below and to the right. Compared to Venus's brilliance
of mag -4.1 though, Saturn is only mag 1.1 and Mars 1.5. By August 7
all three are within 3 or 4 degrees of each other but are only about 8
degrees above the horizon half an hour after sunset so still in a
brightish sky; they then effectively fade from view for this
apparition.

Jupiter, however, is coming to prominence, rising in the east in
the early hours. I had a reasonable view of it. albeit low down
still. at 1am BST on July 15. The NEB (north equatorial belt) is very
prominent and there is a trace of the 'vanished' SEB. I am also
starting to see observations from other sources, what I would describe
as the die-hard amateurs who observe at every opportunity and produce
semi-professional results. At 2am BST Jupiter will have risen to 22
degrees altitude on July 18, 28 degrees on July 31 and 33 degrees on
August 14. Worth making an effort, as you can never know when that
SEB is going to make a dramatic re-appearance!

Uranus is not far from Jupiter throughout this next 4-week period,
just under 3 degrees to Jupiter's right (west). At high power through
a telescope you can see a tiny greenish to slightly bluish disc and
during moments of good seeing you can see limb darkening which I
observed myself a few nights ago in the early hours. Neptune comes to
opposition on August 20, but as it is low down in Capricornus and
presents a tiny blue disc about 2".5 in diameter there is not much
to be seen.

Any reports of observations would be most welcome via:
http://popastro.com/planet/contact/

I post a selection of members' observations on the SPA web site,
and they can be viewed on the Planetary Section's web page at:
http://popastro.com/planet/category/observations/

WAS VENUS ONCE A HABITABLE PLANET?
ESA

If Venus once had oceans, it might have been a habitable planet
similar to the Earth. The Earth and Venus seem completely different
today: here, we have a lush, clement world teeming with life, while
Venus is hellish, its surface roasting at high temperatures. But the
two planets are nearly identical in size, and now, thanks to the Venus
Express orbiter, planetary scientists are seeing other similarities.
One difference stands out: Venus has very little water. Were
the contents of the Earth's oceans to be spread evenly across the
world, they would create a layer 3 kilometres deep. If you could
condense the amount of water vapour in Venus' atmosphere onto its
surface, it would create a global puddle just 3 centimetres deep.

Yet, billions of years ago, Venus probably had more water. Venus
Express has found that the planet has lost a large quantity of water
into space. The loss occurs because ultraviolet radiation from the
Sun streams into Venus' atmosphere and breaks up the water molecules
into atoms, which then escape into space. Venus Express has measured
the rate of escape and found that roughly twice as much hydrogen as
oxygen is escaping. It is believed that water is the source of the
escaping ions. It has also shown that deuterium, a heavy isotope of
hydrogen, is progressively enriched in the upper layers of Venus'
atmosphere because the heavier isotope does not escape so easily.

Everything points to there having been large amounts of water on Venus
in the past, but that does not necessarily mean that there were oceans
on the planet's surface. A newly developed a computer model suggests
that the water was largely atmospheric and existed only during the
earliest times when the surface of the planet was completely molten.
Whether that is true or not is a key question. If Venus ever did
possess surface water, it may possibly have had an early habitable
phase. It is also possible that colliding comets brought additional
water to Venus after the surface crystallized, and that they created
bodies of standing water in which life might have been able to form.

ROSETTA TRIUMPHS AT ASTEROID LUTETIA
Science Daily

ESA's Rosetta mission has returned the first close-up images of the
asteroid Lutetia, showing that it is probably a primitive survivor
from the violent birth of the Solar System. The images show that
Lutetia is heavily cratered, having suffered many impacts during its
4.5 billion years of existence. As Rosetta drew close, a bowl-shaped
depression stretching across much of the asteroid rotated into view.
The images show that Lutetia is an elongated body, with its longest
dimension around 130 km. The pictures come from Rosetta's OSIRIS
instrument, which combines a wide-angle and a narrow-angle camera. At
closest approach, details down to a size of 60 m can be seen over the
entire surface of Lutetia. Rosetta raced past the asteroid at 15
km/s, completing the fly-by in just a minute, but the cameras and
other instruments had been working for hours and in some cases days
beforehand, and will continue afterwards. Ground telescopes have
shown Lutetia to present confusing characteristics. In some respects
it resembles a 'C-type' asteroid, a primitive body left over from the
formation of the Solar System. In others, it looks like an 'M-type',
which have been associated with iron meteorites, are usually reddish
and are thought to be fragments of the cores of much larger objects.

The fly-by marks the attainment of one of Rosetta's main scientific
objectives. The spacecraft will now continue to a 2014 rendezvous
with its primary target, Comet Churyumov-Gerasimenko. It will then
accompany the comet for months, from near the orbit of Jupiter
down to its closest approach to the Sun. In 2014 November
Rosetta will release its Philae lander to land on the comet nucleus.

PROCESSES OF MASSIVE-STAR FORMATION
Joint Astronomy Center, Hilo, Hawaii

Astronomers using the United Kingdom Infrared Telescope (UKIRT)
believe that they have identified the leading mechanism by which
massive stars form in our Galaxy: by collecting matter via discs
around their equatorial regions. That was revealed by the detection
of gas outflows and shocked regions associated with massive young
stars in formation, located in clouds of gas and dust. Scientists
know that lower-mass stars like our Sun form by gravitational collapse
of material inside clouds of gas and dust in space. The gas and dust
spiral down onto the equatorial regions of the young star by a
process known as accretion. At the same time, the accreting young
stars drive high-velocity jets of gas ('outflows') which radiate at
infrared wavelengths, so astronomers can use observations in the
infrared to search for not only the youngest stars, but also evidence
of the accretion process.

There have been misgivings over whether stars with masses larger than
10 times the mass of our Sun form in the same way, as it has been
supposed that the extreme energy output of such stars, which start
nuclear burning in their cores even before they complete their growth
through accretion, would prevent further growth by blowing away the
accretion discs. Hence, alternative mechanisms such as mergers of
lower-mass stars have been suggested as the main way in which massive
stars form. The presence or absence of outflows from massive young
stars should tell us whether accretion or some other method leads to
their formation. Most of the massive young stars being formed are
confined to the Galactic plane and are located in molecular clouds
extending over several or even tens of light-years. They are hidden
behind large amounts of gas and dust, which hamper their detection at
visible wavelengths but are penetrated by infrared light. The UKIRT
observers looked at 50 bright young stellar objects; 38 of them showed
molecular line emission, in most cases arising from outflows. Within
the sample, the outflows are seen to be well-defined irrespective of
the energy output of their central young stars and are nearly as
well-defined as those from low-mass stars. The outflows appear to be
driven by jets like those from low-mass stars. The astronomers have
concluded that massive stars up to at least 30 times the mass of the
Sun form through disc accretion.

ORIGIN OF MILKY WAY'S ANCIENT STARS
RAS

Scientists at Durham and collaborators at the Max Planck Institute and
Groningen University in Holland have tried to make computer
simulations of the beginnings of our Galaxy. The simulations have
suggested that ancient stars found in a stellar halo of debris
surrounding the Milky Way were ripped from smaller galaxies by the
gravitational forces generated by colliding galaxies. Cosmologists
think that the early Universe was full of small galaxies which led
short and violent lives, colliding with one another and leaving behind
debris which eventually settled into more familiar-looking galaxies
like the Milky Way.

UNRAVELLING THE NATURE OF HANNY'S VOORWERP
ASTRON, Dwingeloo, Netherlands

A group of researchers has made high-resolution radio observations
of the region of space around Hanny's Voorwerp (Hanny's Object), the
curious, greenish gas cloud discovered by Dutch schoolteacher Hanny
van Arkel. The astronomers undertook an observational campaign at
radio wavelengths in which several radio telescopes across Europe and
the United Kingdom were linked together in real time in order to
obtain a detailed picture of the central region of the adjacent galaxy
IC 2497. They observed a field a few arcseconds across, with a
spatial resolution of about 70 milliseconds. The observations show
two bright and very compact sources with broadband spectra that argue
for the existence of an active galactic nucleus (AGN) at the centre
of IC 2497. One of the sources appears to be identifiable with a
supposed black hole at the centre of the AGN itself, while the other
is likely to be the result of an energetic jet expelled by the black
hole and now interacting with dense gas that surrounds IC 2497. The
radiation from the AGN is believed to heat Hanny's Voorwerp to a
temperature above 10,000°.

It also appears that surrounding the AGN is a lot of extended radio
emission. The researchers argue that it is associated with a nuclear
starburst. Astronomers knew that IC 2497 is forming stars, but were
surprised to find that the star formation seems to be concentrated in
a very small central region, only 1000 parsecs across. It is fairly
unusual to find both vigorous star formation and AGN radio activity in
the same system and on similar scales. The radio observations
indicate that in the central region IC 2497 is producing stars with a
total mass of the order of 70 Suns every year -- a high rate, about 6
times higher than in the nearby starburst galaxy M82.

The observations support the group's earlier hypothesis that a hidden
AGN in the centre of IC 2497 is ionizing a distinct region of gas that
surrounds that galaxy. That distinct region is what is known as
Hanny's Voorwerp. Such phenomena must be rare in the local Universe
because they depend on a specific geometry of the observer, galaxy,
and gas, plus the interaction of several galaxies in the field in
order to fuel the AGN and the starburst, and to create the gas
reservoir that forms part of the Voorwerp.

VOYAGER SPACECRAFT AT 12,000 DAYS
Science Daily

On June 28, the Voyager 2 spacecraft had been operating continuously
for 12,000 days. For nearly 33 years, the venerable spacecraft has
been returning data about the outer planets, and the characteristics
and interaction of the solar wind between and beyond the planets.
Among its findings, Voyager 2 discovered Neptune's Great Dark Spot and
its 450-m/s winds. The two Voyager spacecraft have been the longest
continuously operating spacecraft in deep space. Voyager 2 was
launched on 1977 August 20; Voyager 1 was a little later, on
1977 September 5, so it reached its 12,0000 days on July 14. The two
spacecraft are the most distant man-made objects, out at the edge of
the heliosphere -- the bubble that the Sun creates around the Solar
System. Having travelled more than 21 billion kilometres on its
winding path among the planets towards interstellar space, Voyager 2
is now nearly 14 billion kilometres away; a signal from the ground,
travelling at the speed of light, takes about 12.8 hours one-way to
reach it. Voyager 1 is even further away, more than 17 billion
kilometres.

Bulletin compiled by Clive Down

                 ***********************************
                  The SOCIETY for POPULAR ASTRONOMY
                 ***********************************
         ====================================================
          Electronic News Bulletin No. 291      2010 June 27
         ====================================================

Here is the latest round-up of news from the Society for Popular
Astronomy. The SPA is Britain's liveliest astronomical society, with
members all over the world. We accept subscription payments online
at our secure site and can take credit and debit cards. You can join
or renew via a secure server or just see how much we have to offer by
visiting http://www.popastro.com/

JUNE BOÖTIDS - INITIAL IMPRESSIONS
By Alastair McBeath, SPA Meteor Section Director

As noted last time, the June Boötids were predicted to produce some
fresh activity on June 23-24, with Zenithal Hourly Rates (ZHRs)
perhaps comparable to the ~20-50 level that happened at their previous
significant return in 2004. Early indications are that some observers
did detect visual activity from the shower over parts of Europe then,
and several video meteor systems recorded a number of June Boötids as
well. Probable Boötid rates were reported from around 20h UT on June
23 to 02:30 on June 24. Four potential peaks were predicted, centred
at 22:40, 00:07, 01:22 and 03:53 UT that night. So far, there is no
good indication that any of those specific timings produced unusual
Boötid numbers.

Boötid ZHRs have been difficult to compute so far, because observers
seem to have struggled with conditions -- including problems due to
the bright Moon, and sometimes clouds and haze. Intriguingly, not all
the visual observers reported seeing some June Boötids during the
interval noted above either. My initial impression, based on details
reported to the IMO-News and Meteorobs electronic mailing lists
(archived via their respective home pages, http://www.imo.net , and
http://www.meteorobs.org ), as well as more directly, could imply that
even where Boötid rates were claimed, ZHRs may not have been
impressive, perhaps just 10 or so. Video Boötid numbers also seem to
have been quite low, somewhere between similar to, to well below, the
sporadic numbers recorded during the same time. It is too soon to
comment on how accurate or representative these very preliminary
estimates may have been. However, if correct, the overall pattern
could suggest that the dust trails may have been less concentrated
than expected, and given a broader, but less active, maximum around
and across the four timing predictions.

No positive UK visual reports from June 23-24 have reached the Meteor
Section as yet, with the usual weather problems at fault, according to
the few people to get in touch soon after the expected event.
Accordingly, all further June Boötid data would be gratefully
received!

MAY 14-15 FIREBALL
By Alastair McBeath, SPA Meteor Section Director

More details have been established now for the 01:18 UT fireball on
May 14-15, noted last time, seen from Warwickshire and imaged from the
Netherlands by Klaas Jobse's all-sky fireball camera system. Although
no very precise analysis was possible, it is likely the fireball flew
on a roughly southeast to northwest trajectory above East Anglia,
possibly starting from a point around 90-100 km altitude above
central-northern Essex, somewhere between ~10 km south of Colchester
to ~20 km west of that city. The last imaged point on the trail,
which was almost certainly not the true end, could have been 10 km or
so south of Peterborough in Cambridgeshire, at an altitude of ~50 km.
Extrapolating from these rough estimates could imply the true end was
maybe at 45 +/- 5 km altitude above a point ~20 km northwest of
Peterborough. Taking these values as approximately correct would lead
to an atmospheric path length for the fireball of ~120-125 km,
descending at an angle of 20°-30° from the horizontal. The visual
observer's estimate for the event's duration of three to four seconds
would in turn infer an atmospheric velocity, not allowing for
deceleration, of ~35 +/- 7 km/s, thus about medium-speed on the 11 to
72 km/sec meteor atmospheric velocity scale. Although additional data
would be needed to confirm all these points, they do fit plausibly
within the expected ranges for fireball-class meteors. There is no
evidence to suggest that a meteorite fall happened following this
meteor, but continuing the estimated trajectory to the surface might
have suggested a speculative arrival zone roughly on or east of a line
from about Nottingham north-northwest to the Leeds area of central
England.

Fireball observations from the British Isles and nearby are always
welcomed by the Meteor Section. (A fireball is any meteor that
reaches at least magnitude -3 at its brightest.) Information on what
to send and where to is available on the "Making and Reporting
Fireball Observations" webpage, at:http://snipurl.com/u8aer , which
includes a report form suitable for e-mailing.

SOME COMETS MAY HAVE COME FROM OTHER STARS
SwRI,

Many comets may have been born in orbit around other stars, according
to astronomers from the Southwest Research Institute (SwRI) in
Boulder, Colorado. The team's computer simulations suggested that the
Sun may have captured small icy bodies from other stars while it was
in its birth star cluster. While the Sun currently has no companion
stars, it is believed to have formed, with many other stars, from a
dense cloud of interstellar gas. In the early stages, many of the
stars may have formed lots of small icy bodies -- comets -- in discs
from which planets may have formed. Most of the comets could have
been ejected gravitationally from their original systems by newly
forming giant planets, becoming free-floating members of the cluster.
The Sun's cluster came to a violent end, however, when the hottest
young stars blew away its remaining gas. The new models indicate that
the Sun could have captured a large cloud of comets as the cluster
dispersed. The process of capture is surprisingly efficient and leads
to the possibility that the cloud consists of a potpourri of material
from other stars that formed with the Sun.

ANCIENT OCEAN MAY HAVE COVERED ONE-THIRD OF MARS
University of Colorado, Boulder

An ocean may have covered one-third of the surface of Mars some 3.5
billion years ago, according to a new study conducted by scientists at
the University of Colorado in Boulder. The study is the first to
combine the analysis of water-related features, including scores of
delta deposits and thousands of river valleys, to test for the
occurrence of an ocean sustained by a global hydrosphere on early
Mars. While the notion of a large, ancient ocean on Mars has been
repeatedly proposed and challenged, the new study provides support for
the idea that a sustained sea existed on Mars more than 3 billion
years ago. More than half of the 52 river delta deposits identified
by the researchers in the new study -- each of which was fed by
numerous river valleys -- probably marked the boundaries of the
proposed ocean, since all were at about the same elevation.
Twenty-nine of the 52 deltas were connected either to the ancient Mars
ocean or to the ground-water table of the ocean and to several large
adjacent lakes. The study implies that ancient Mars probably had an
Earth-like hydrological cycle, including precipitation, runoff, cloud
formation, and ice and ground-water accumulation. Researchers
concluded that the ocean might have covered about 36% of the planet
and contained about 124 million cubic kilometres of water, about a
tenth of the total in the Earth's oceans.

METEOR PROBABLY CAUSED FLASH ON JUPITER
STScI

Observations made by the Hubble telescope have failed to find an
origin for the flash of light seen on Jupiter on June 3. The only
plausible explanation seems to be that it came from a meteor that
burnt up above Jupiter's cloud tops and did not plunge deep enough
into the atmosphere to explode and leave behind any telltale clouds of
debris such as have been seen after previous Jupiter collisions.
Australian amateur astronomer Anthony Wesley saw the flash when he was
watching a live video feed of Jupiter from his telescope. In the
Philippines, amateur astronomer Christopher Go confirmed that he had
simultaneously recorded the transitory event on video. The two-second
flash of light in the videos of Jupiter was presumably created in the
same way as a meteor trail on Earth. A shock wave generated by ram
pressure as the meteor speeds into the planet's atmosphere heats the
impacting body to a high temperature, and as the hot object streaks
through the atmosphere, it leaves behind a glowing trail of
superheated atmospheric gases and vaporized meteor material that
rapidly cools and fades in just a few seconds. Though astronomers are
very uncertain about the rate of large meteoroid impacts on the
planets, the best guess for Jupiter is that the smallest detectable
events may happen as frequently as every few weeks. The meteor
flashes are so brief that they are easily missed, even in video
recordings, or perhaps misidentified as detector noise or cosmic-ray
hits on imaging devices.

Obviously something must have hit the planet to produce a flash bright
enough to be seen from here. Images taken by Hubble 3 days after the
flash was sighted showed no sign of debris above Jupiter's cloud tops.
That has been interpreted to mean that the object did not penetrate
beneath the clouds and explode as a fireball. If it did, previous
events would lead to an expectation that dark blast debris would have
been ejected and would have rained down onto the cloud tops, and the
impact site would have appeared dark. Dark smudges marred Jupiter's
atmosphere when a series of comet fragments hit the planet in 1994.
A similar phenomenon occurred last July when a suspected asteroid
collided with Jupiter. The latest impactor is thought to have been
smaller than those earlier ones.

EXO-PLANET SEEN TO HAVE MOVED
ESO

For the first time, astronomers have been able to follow the motion of
an exo-planet (that of Beta Pictoris) as it moves from one side of its
host star to the other. Images are available for approximately 10
exo-planets, and the planet around Beta Pictoris has the smallest
orbit known so far. It is at a distance between 8 to 15 astronomical
units -- about the distance of Saturn from the Sun. Only 12 million
years old, Beta Pictoris is 75% more massive than the Sun. It is
about 20 parsecs away (1 parsed is about 3.26 light-years) and is one
of the best-known examples of a star surrounded by a dusty debris
disc. Earlier observations showed a warp of the disc, a secondary
inclined disc, and some evidence of comets falling onto the star.
Those were indirect but telltale signs that suggested the presence of
a massive planet, whose existence is now supported by new
observations. Because the star is young, the discovery shows that
gas-giant planets can form in only a few million years, a short time
in cosmic terms.

The team used one of the 8.2-metre VLT telescopes to study the
immediate surroundings of Beta Pictoris in 2003, 2008 and 2009.
In 2003, a faint source was seen inside the disc, but it was not
possible to exclude the remote possibility that it was a background
star. In images taken in 2008 and spring 2009 the source had
disappeared. The most recent observations, taken in late 2009, showed
an object (presumed to be the same one as in 2003) on the other side
of the disc, so it seems certain that the source is a planet and that
it is orbiting the star. The short period will allow astronomers to
record the full orbit within 15 to 20 years. The planet has a mass of
about 9 Jupiter masses and the right mass and location to explain the
observed warp in the inner parts of the disc.

ANTHRACENE FOUND IN INTERSTELLAR SPACE
RAS

Anthracene molecules have been identified in an interstellar cloud in
the direction of the star BD +31 540 in Perseus, about 200 parsecs
away. Anthracene is one of the most complex carbon-containing
molecules yet found in the interstellar medium. It consists of three
fused benzene rings, containing a total of 14 carbon atoms, with a
hydrogen atom at each of the ten 'free' corners. Until now,
anthracene had been detected only in meteorites and never in the
interstellar medium.

DOUBTS ABOUT THE DARK SIDE
RAS

Research by astronomers using observations from the Wilkinson
Microwave Anisotropy Probe (WMAP) suggests that the recent allegations
about the content of the Universe may be wrong. The scientists found
evidence that the errors in the data may be much larger than
previously thought, which in turn makes the conclusions drawn from
them open to question. Launched in 2001, WMAP measures the small
differences in intensity between different directions in the Cosmic
Microwave Background (CMB) radiation, the residual heat of the Big
Bang that fills the Universe and appears over the whole of the sky.
The angular size of the ripples in the CMB is thought to be connected
with the composition of the Universe. The observations of WMAP showed
that the ripples were about twice the size of the full Moon, or around
a degree across. Just from those results, some scientists concluded
that the cosmos is made up of 4% normal matter, 22% 'dark' or
invisible matter and 74% "dark energy" -- simply a name for what was
otherwise unaccounted for.

The team used astronomical objects that appear as unresolved points
in radio telescopes to test the way the WMAP telescope smoothes
its maps. They find that the smoothing is much larger than
previously believed, suggesting that its measurement of the size of
the CMB ripples is not as accurate as was thought. If true, that
could mean that the ripples are significantly smaller, which could
imply that dark matter and "dark energy" are not present after all.
In addition, the astronomers recently collaborated in an international
team whose research suggested that the structure of the CMB may not
provide the independent check on the presence of "dark energy" that it
was thought to do.

If "dark energy" were to exist, then it has been thought to cause the
expansion of the Universe to accelerate. On their journey from the
CMB to WMAP, photons travel through superclusters of galaxies. The
photon is first blueshifted when it enters the supercluster and then
redshifted as it leaves, so the two effects cancel. However, if the
supercluster galaxies are accelerating away from each other because of
dark energy, the cancellation is not exact, so photons stay slightly
blueshifted after their passage. Slightly higher temperatures should
appear in the CMB where the photons have passed through superclusters.
However, the new results, based on the Sloan Digital Sky Survey which
surveyed 1 million luminous red galaxies, suggest that no such effect
is seen, again threatening the recent models of the Universe. If the
result is repeated in new surveys of galaxies in the southern
hemisphere then it will pull the rug out from under dark energy.

If the Universe really has no 'dark side', it will come as a relief to
some theoretical physicists. Having a model that depends on as-yet-
undetected exotic particles that might make up dark matter and the
completely unexplained dark energy has left real scientists feeling
uncomfortable. It also throws up problems for the birth of stars in
galaxies, with as much 'feedback' energy needed to prevent their
creation as gravity provides to help them form. The European PLANCK
satellite, currently collecting more CMB data, is expected to provide
new information and help to answer fundamental questions about
the nature of the Universe we live in.

HAYABUSA RETURNS TO EARTH
NASA

The sample capsule from the asteroid explorer Hayabusa, launched in
2003 by the Japan Aerospace Exploration Agency (JAXA) has returned to
Earth. With Hayabusa, JAXA scientists and engineers hoped to obtain
detailed information on electrical propulsion and autonomous
navigation, as well as an asteroid sampler and sample re-entry
capsule. The 510-kg Hayabusa spacecraft reached the asteroid Itokawa
in 2005 September. Over the next 2.5 months, it made scientific
observations of the asteroid's shape, surface, surface altitude
distribution, mineral composition, gravity, and the way it reflected
the Sun's radiation. On November 25 of that year, the craft briefly
touched down on the surface of Itokawa and attempted to sample
asteroid surface material, but there seemed to be a malfunction in the
sample-collection process. Nevertheless, scientists hope to find some
of the asteroid's surface material in the capsule.

ROSETTA SET TO ENCOUNTER ASTEROID LUTETIA
Science Daily

The European Space Agency's comet-chaser Rosetta is expected to pass
to within 3300 km of asteroid Lutetia on July 10. Rosetta started
taking navigational sightings of Lutetia at the end of May so that
ground controllers could determine any course corrections required to
achieve their intended fly-by distance. The close pass will allow
around 2 hours of good imaging. The spacecraft will instantly begin
beaming the data back to Earth and the first pictures will be released
later that evening. Rosetta flew by asteroid Steins in 2008 and other
space missions have encountered a number of asteroids, each of which
has proven to have its individual character. At present, no one knows
what Lutetia looks like. Orbiting in the main belt of asteroids
between Mars and Jupiter, it appears just as a point of light to
ground telescopes, although its magnitude suggests that it has
dimensions of the order of 100 km. A continuous variation in its
brightness makes it clear that Lutetia is rotating and has an uneven
surface.

Owing to holidays, the next scheduled bulletin will be issued on July
18.

Bulletin compiled by Clive Down