It is currently Wed Apr 16, 2014 4:10 am

Post new topic Reply to topic  [ 1 post ] 
Author Message
PostPosted: Wed Dec 03, 2008 7:43 am 

Joined: Fri Dec 03, 2004 11:24 am
Posts: 4293
Location: Greenwich, London
Electronic News Bulletin No. 256 2008 November 30

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


If you are not already a member of the SPA, now is a great time to
join! We are offering to those who receive ENBs and are not already
members a SPECIAL JOINING PRICE of only £12.00, saving £4.00 on the
usual UK annual rate. (Overseas rates vary but discount still applies
-- see our website for details.)

Join NOW by going to our secure website at and click
the 'Join Online' button. To claim the your discount enter JOINPROMO
when asked for your voucher reference. To join by post send your
details with payment to: SPA Membership, 36 Fairway, Keyworth,
Nottingham, NG12 5DU, quoting reference JOINPROMO.

Please Note -- This offer is valid only until 2008 December 31 and
does not apply to renewals of membership.

By Jon Harper, Occultations Section Director

It takes place on Monday, December 1, low in the SSW during the late
afternoon/early evening. Venus, at magnitude -4.1, will be
occulted at the Moon's dark limb as the Sun sets and reappear at
the bright limb about 90 minutes later. The disc of Venus is 16.6
seconds of arc in diameter and is 69% illuminated, exhibiting a
gibbous phase. It will take between 45 and 50 seconds for the disc to
disappear behind the Moon, and subsequently for it to reappear. The
Moon itself will be a waxing crescent, 3.9 days after New, and 13%
illuminated. Jupiter is in conjunction with the pair at the same time
and is about 2° above Venus in eastern Sagittarius.

Details including graphics are in the last issue of Popular Astronomy,
and also on my web page:

Predicted timings (UT) are as follows:

Place Disapp. Reapp.

Penzance 15:37 17:11
Bristol 15:42 17:14
Swansea 15:40 17:12
London 15:46 17:16
Birmingham 15:43 17:13
Norwich 15:48 17:17
Manchester 15:42 17:12
Hull 15:45 17:14
Douglas 15:39 17:09
Newcastle 15:43 17:13
Belfast 15:37 17:07
Edinburgh 15:41 17:09
Inverness 15:39 17:07

Peter Grego, Lunar Director, is attempting to make a web cast of the
occultation from his home in Cornwall, or in the event of overcast
skies, a simulation of the event. Web:

By Robin Scagell SPA Vice President

It should be possible from the UK to view with binoculars the toolbag
lost overboard from the International Space Station (ISS), and to
photograph the object as a trail in the sky. But the object is faint
and you will need a reasonable familiarity with the stars in order to
look at exactly the right point in the sky as it comes over. It will
look like a small starlike point moving fairly rapidly through the
sky, easily distinguishable from a plane because it hasn't got red and
green navigation lights. The ISS is easily visible, and will make a
series of evening passes over the UK during the end of November and
the start of December. Instructions on how to observe it can be found
on the SPA website:

By Alastair McBeath, SPA Meteor Section Director

At 00:27 UT (17:27 local time) on November 20-21, a spectacular
fireball lit up the skies over Alberta and Saskatchewan in western
Canada. Sonic booms were reported from various places, and the
object itself seems to have passed somewhere to the east of
Edmonton and Calgary in Alberta. Meteorites claimed as having fallen
from it have been recovered near the town of Lloydminster in Alberta,
by the Saskatchewan border. The fireball was imaged from a number
of places, and there are links to video footage of it, and images of the
meteorites (see the link), on the Observing Forum topic at: . Grateful thanks go to Section correspondent
Jeff Brower in British Columbia, Canada too for clarifying details on
the event. Though the Section normally deals primarily with fireball-
class meteors seen just from the British Isles and places nearby, some
of the imaging of this event was too impressive to ignore! Anyone who
has spotted a fireball - any meteor reaching magnitude -3 or brighter -
from closer to the UK is welcome to send in a full report as soon as
possible. Advice on what details to provide is outlined on the "Fireball
Observing" page of the SPA website, at: .

By Alastair McBeath, SPA Meteor Section Director

A strong return from the Leonids, producing Zenithal Hourly Rates,
ZHRs, up to 100 or so, happened overnight for Europe on November
16-17, probably peaking around 02:00 UT. Unfortunately, UK watchers
seem to have missed out thanks to some very poor weather that night,
apart from the problems posed by the bright Moon. Details on the
"live" International Meteor Organization (IMO) Leonid results page, at: have suggested ZHRs from the
shower were 35 or above from at least 23:20 UT on November 16 to
03:40 UT on the 17th, and for much of that time, seemed to have been
running at more than 50. The very best activity, ZHRs 90-110,
appeared to last for perhaps 20 minutes or more to either side of
02:00 UT. The actual values and timings are subject to revision as
more data comes through, and need to be treated with a degree of
caution because of the moonlight, but video data posted on the IMO-
News e-mail list and elsewhere also supported the highest Leonid
rates as happening close to 02:00 UT. A healthy number of brighter
meteors was reported as present during this near-maximum activity,
but it is not possible yet to say whether this was because of more bright
Leonids than normal, or simply because their activity was so good.

Assistant SPA Meteor Director David Entwistle has made a preliminary
analysis of the radio meteor results he recorded in England, along with
data from colleagues Enric Fraile Algeciras (Spain), Andy Smith
(England), Dave Swan (England) and Felix Verbelen (Belgium) - full
details should be in November's Radio Meteor Observation Bulletin
(RMOB), via , before mid December - plus
combined results from several observers in Japan kindly provided to
David by Hirofumi Sugimoto. Jeff Brower in Canada also sent in some
notes from an initial survey of his own radio results from British
Columbia. Activity pushed beyond that seen on days to either side due
to the Leonids only from about 00h-01h UT onwards on November
16-17, but then lasted at an elevated level through till 05h-06h UT.
There was a clear echo-count peak in most of the systems around
02h-03h, and a suggestion that brighter meteors may have been
somewhat more prevalent from about 02h-04h UT overall. One dataset
also indicated there may have been more bright Leonids again
towards the "traditional", or nodal crossing-point, time, around 07h-09h
UT on November 17. It is not clear if the predicted minor Leonid peak
around 21:35 UT on November 18-19 was detected too. The Japanese
results hinted at a possible small Leonid peak around 20h-21h then,
perhaps at best close to 20:05, but no visual or video results are yet
available from a similar interval for comparison. Grateful thanks are
due to these contributing observers, and commiserations to all those
who missed-out.

Leonid rates were thus well above the usual ~15-20 at best, but
interestingly, the timing of the main peak was significantly later, by
between 0.5 to 1.5 hours, than any of the predictions (see ENB 254, ). One of the professional analysts most
closely involved, Jeremie Vaubaillon at the California Institute of
Technology, has since circulated some notes on IMO-News (on
November 25) about what this may mean for the Earth's even closer
encounter with the same meteoroid trail, laid down by
Comet 55P/Tempel-Tuttle at its 1466 AD return, next year. He
suggested the timing could be 30 to 60 minutes later than the predicted
peak, due around 21:43 UT on November 17-18. This could mean the
maximum then might fall not far from the ~23h UT radiant-rise time for
the UK, and given that ZHRs may be up to 500, it is possible something
of the event may be seen from here. Further updates on this prediction
are likely - see for more. One thing is certain for
the 2009 Leonid return. New Moon is on November 16!

By Alastair McBeath, SPA Meteor Section Director

Conflicting reports regarding the possible Taurid "swarm" return (on
which see the notes in ENBs 253, at , and 254 -
address above), perhaps including better than usual brighter meteor
activity, have continued to appear since the previous ENB. The most
convincing evidence remains the IMO's pair of "live" Taurid results
webpages, which have still indicated elevated combined ZHRs,
perhaps up to 20 on November 5, were present in the first few days of
November. However, the magnitude distribution for these meteors
appeared to be quite normal. Some of the late October RMOB data
hinted at perhaps marginally more bright to fireball-class meteors
generally for a few days near the end of the month, though this cannot
be confirmed as due to the Taurids. SPA correspondent Bob Lunsford
of the American Meteor Society, AMS, has recently reported an
exceptionally busy November thanks to a large number of fireball
reports from across North America, though as with the SPA late
October fireballs noted last time, it has not been possible to identify
their origins with certainty very often. The AMS fireballs listing can be
found via their homepage at: . The IMO's
Video Commission Director Sirko Molau reported in his monthly video
review for October on IMO-News (posted on November 24) a hint of
somewhat brighter Taurids near the end of October only. Regular
SPA video contributor Enrico Stomeo in Italy has provided data from
various better nights between October 25-26 and November 1-2
recently which also suggested slightly brighter Taurids may have been
present from October 26-27 to November 1-2, but the overall Taurid
numbers were small enough to make this most uncertain. Hopefully,
November's complete radio and video results will reveal more.

By Alastair McBeath, SPA Meteor Section Director

The clutch of four single-observer fireballs on October 5-6, noted in
ENB 254, which were earlier suggested as possibly connected to the
video-detected bright-meteor shower radiating from near Draco's tail-
tip found in both 2005 and 2006, now seems less likely to have been
linked to it after all. One, at 20:08 UT, had already been discounted as
possibly associated from the initial report, and further information from
the witness of the ~03:10 UT event has now allowed it to be excluded
as possibly radiating from this Draco source too. No video confirmation
of the shower was made in 2008 from Europe either.

By Alastair McBeath, SPA Meteor Section Director

After being full on December 12, the Moon will pass through Gemini, a
few degrees south of the Geminid radiant around the shower's
maximum, expected on December 13-14, within about 2h20m of 23h
UT. Consequently, both Moon and radiant will be visible all night, and
will be very well on-view from Britain by the predicted peak time. The
radiant reaches a usefully-observable elevation for meteor watchers by
about 20h UT in the UK, after which it remains nicely-placed for the rest
of the night, culminating around 02h. Highest ZHRs should be ~120
judging by recent returns, a strength that means something of the peak
should still be visible under clear skies despite the Moon, and Geminid
rates often remain near maximum levels for 6-10 hours to either side
of their best too. Geminids are medium speed and often bright meteors,
though few leave persistent trains after them. Much lower Geminid rates
may be seen away from the maximum night in any darker skies
available between December 7 to 17, judging by activity in past years.
Although the shower's parent object, Apollo asteroid 3200 Phaethon
(possibly a dormant or extinct comet) passed closest to Earth since its
1983 discovery on 2007 December 10, it seems not to have affected
Geminid rates then (it was not anticipated it would), nor is it expected
to this time.

Ursid activity usually lasts from December 17-26, but is typically low to
undetectable early and late in this spell. The shower's radiant at
maximum is near Kochab, the brighter of the two "Guard" stars in Ursa
Minor, so is consequently circumpolar from the UK, though highest
towards dawn. The shower has been greatly under-observed, thanks to
its proximity to the festive season, and frequently unhelpful winter
weather. This year, the peak is scheduled to fall between ~07h30m-
10h UT on December 22, in strong early morning twilight to full daylight
for Britain. Maximum ZHRs can be between 10-50 or so (they were ~30
for a time in 2000, 2006 and 2007 recently), though only at very rare
previous returns had the activity exceeded ~10-15. The last strongest
enhancements were in 1945 and 1986, with other lesser events in
1988 and 1994. If the peak timing is unfavourable for Britain, at least
there will be little moonlight, with the Moon waning to new on
December 27. It is worth noting though that some of the recent
enhancements have happened at times other than this predicted
maximum interval. The 2007 event happened about twenty hours after
the equivalent interval then, for instance. The proximity of the shower's
parent, Comet 8P/Tuttle, at perihelion on January 26 this year seems
to have helped produce the unusual activity in 2006-2007, and may do
so again in 2009, so it would be worthwhile keeping watch throughout
both December 21-22 and 22-23 this year in any better skies, just in
case something happens this year too. Typical Ursid meteors are faint,
and of slow to medium speed.

For more information and a Geminid radiant chart, see the December
meteor activity webpage at: .

Science Daily

The Hubble telescope has taken the first visible-light photo of a
planet circling another star. Estimated to be no more than three
times Jupiter's mass, the planet, called Fomalhaut b, orbits the
bright southern star Fomalhaut, located 25 light-years away in the
constellation Piscis Austrinus. Fomalhaut has been a candidate for
planet-hunting ever since an excess of dust (supposed to be a sign of
planet formation) was discovered around it in the early 1980s by
the Infrared Astronomy Satellite. In 2004 Hubble produced a visible-
light image of the region around the star and clearly showed a ring of
proto-planetary debris approximately 20 billion miles across and
having a sharp inner edge. That large debris disc is similar to the
Kuiper Belt, which encircles the Solar System and contains a range of
icy bodies from dust grains to objects the size of dwarf planets such
as Pluto.

Astronomers proposed in 2005 that the ring was being gravitationally
modified or 'shepherded' by a planet lying between the star and the
ring's inner edge. Now, Hubble has actually photographed a point
source of light lying 1.8 billion miles inside the ring's inner edge.
Observations taken 21 months apart show that the object is moving
along a path around the star, and is therefore gravitationally bound
to it. The planet is about 10 times the distance of the planet Saturn
from our Sun and is brighter than expected for an object of three
Jupiter masses. One possibility is that it has a Saturn-like ring of
ice and dust reflecting starlight. Astrometric measurements of
the planet's orbit should in due course yield an accurate mass.


Astronomers using ESO's Very Large Telescope have imaged an object
located very close to the star Beta Pictoris, and which apparently
lies inside its disc. At a projected distance from the star of 8
times the Earth-Sun distance, the object is probably the giant planet
that has already been suspected. If so, it would be the first
directly observed planet that is as close to its host star as Saturn
is to the Sun. The hot star Beta Pictoris is one of the best-known
examples of stars surrounded by a dusty 'debris' disc. Debris discs
are composed of dust presumed to result from collisions among larger
bodies like planetary embryos or asteroids. They are bigger versions
of the zodiacal dust in our Solar System. The Beta Pictoris disc was
the first to be imaged, in 1984, and remains the best-studied one.
Earlier observations showed a warp of the disc, a secondary inclined
disc and infalling comets onto the star. Those are considered to be
signs of the presence of a massive planet lying between 5 and 10
times the Earth-Sun distance from the host star.

Observing such a planet so close to its star is difficult. In 2003,
the team used one of the 8.2-m Unit Telescopes of the VLT to study the
immediate surroundings of Beta Pictoris. Recently, a member of the
team re-analysed the data in a different way to seek the trace of a
companion to the star. The principle was to identify and subtract as
accurately as possible the bright stellar halo. There remained a
feeble, point-like source well inside the halo. To reduce the
probability that it was an artefact and not a real object, suitable
tests were made, and several members of the team, using three
different methods, did the analysis independently, always with the
same result. Moreover, the companion was also discovered in other
data sets. The observations point to the presence of a giant planet,
about 8 times as massive as Jupiter and with a projected distance
from its star of about 8 times the Earth-Sun distance. The fact that
the candidate companion appears to lie in the plane of the disc also
implies that it is bound to the star and its proto-planetary disc.
Moreover, it has the right mass and distance from its star to explain
the disc's properties.


Most galaxies are either blue spiral ones like the Milky Way or
Andromeda, or red elliptical ones. Now astronomers have noticed some
red spiral galaxies that could be the missing link between the two
classes. Because blue stars are generally younger and hotter, while
red stars tend to be older and cooler, most bluish spiral galaxies are
thought to be young compared to the reddish ellipticals. Astronomers
think that spirals are actively forming stars, with the newly born
stars giving the galaxies their blue colour.

Astronomers at the University of Nottingham claim that in order to
have spiral arms, the red spiral galaxies must have been normal, blue,
ones until fairly recently, but for some reason their star formation
has been stopped, and they have turned red. Whatever caused them to
stop forming stars cannot have been particularly violent, or it would
have destroyed the delicate spiral pattern. The red spirals tend to
be found near locations crowded with other galaxies, and the
scientists suspect that their environment may have played a role in
slowing down star formation, although no mechanism has been
identified. A galaxy's mass also affects how it ages. The red
spirals tend to be more massive galaxies, and the scientists suggest
that smaller galaxies cannot retain their spiral arms for long after
star formation shuts down, and transform more quickly into smooth,
lens-shaped galaxies. To complete the changeover into full-blown
ellipticals, a violent event such as a collision between galaxies is
probably also needed. A large galaxy is more resistant to disturbance
by its local environment, so it is presumed that the reason that the
red spirals tend to be the larger galaxies is that the smaller ones
are transformed more quickly.


Astronomers have observed violent flares from the centre of the Milky
Way. They used the VLT and the Atacama Pathfinder Experiment (APEX)
telescope to study light from Sagittarius A* at near-infrared and
sub-millimetre wavelengths respectively. Sagittarius A* is located at
the centre of our Galaxy at a distance of about 26000 light-years.
It is thought to be a black hole with a mass about four million times
that of the Sun. Its emission is supposed to come from gas thrown off
by stars, which then orbits and falls into the black hole.

After several nights' waiting at the two observatory sites,
astronomers at the VLT noticed that Sagittarius A* was active, and
getting brighter by the minute. They immediately alerted colleagues
at the APEX telescope who were able to observe the flares. Over the
next six hours, the team detected violently variable infrared
emission, with four major flares from Sagittarius A* . The sub-
millimetre observations also showed flares, but they occurred about
one and a half hours after the infrared ones. The researchers think
that the time delay may be caused by the rapid expansion, at speeds of
about 1500 km/s, of the clouds of gas that are emitting the flares.
Although 1500 km/s sounds fast, it is only 0.5% of the speed of light.
To escape from the very strong gravity so close to the black hole, the
gas would have to be travelling 100 times as fast -- half the speed of
light -- so the researchers believe that the gas cannot be streaming
out in a jet. Instead, they suspect that a blob of gas orbiting close
to the black hole is being stretched out, and that is what constitutes
the expansion.

Science Daily

The Moon Impact Probe is the first Indian-built object to reach the
surface of the Moon. It hit the Moon near the south pole. Weighing
34 kg at the time of its launch on board Chandrayaan-1, the MIP
carried three instruments -- a video imaging system, a radar altimeter
and a mass spectrometer. The video imaging system was intended to
take the pictures of the Moon's surface as MIP approached it. The
radar altimeter was included to measure the rate of descent of the
probe to the lunar surface; such instruments will be necessary for
future soft-landing missions.


NASA is planning a new study of Jupiter. Called Juno, the spacecraft
will placed in a highly eccentric polar orbit around Jupiter to
investigate its formation, evolution and structure. Underneath
Jupiter's dense cloud cover, there may be clues to the fundamental
processes and conditions that governed our early Solar System. The
spacecraft is scheduled to be launched in 2011 and to reach Jupiter in
2016. It will orbit Jupiter 32 times, skimming about 4800 km above
the cloud tops at perijove passages, for approximately one year. The
mission will be the first solar-powered spacecraft designed to operate
at such a great distance from the Sun.


Repairing the Large Hadron Collider near Geneva is expected to cost
almost £14 million. An electrical failure shut the machine down in
September. The European Organization for Nuclear Research (CERN)
thought it would be out of action only until November, but the damage
was worse than expected. It is hoped that repairs will be completed
by May or early June; the machine will not be able to be re-started
until at least the end of June. The failure occurred just nine days
after the LHC was turned on, with CERN blaming it on a single badly
soldered electrical connection in one of its super-cooled magnets.
The collider operates at temperatures colder than those of outer space
for maximum efficiency, and experts needed gradually to warm the
damaged section to assess it. The cost of the work will fall within
the existing budget.


From next year pupils in 1 in 4 secondary schools will get views of
the Moon, planets and stars, in one of the largest astronomical
outreach projects ever seen in the UK. The Society for Popular
Astronomy (SPA), Royal Astronomical Society and Science and Technology
Facilities Council have collaborated to give free telescopes to 1000
secondary schools from early in 2009. The project -- Telescopes for
Schools -- is part of the effort to celebrate the designation of 2009
as the International Year of Astronomy, which commemorates the 400th
anniversary of Galileo's first use of the telescope for astronomy,
work that led to a scientific revolution.

Four centuries later, astronomers hope to achieve a different kind of
revolution in UK schools -- using the 1000 telescopes to enthuse
students about science. The project aims to attract them to astronomy
and space science as well as to the underpinning subjects like physics
and mathematics. The participating schools will receive a DVD with
clips explaining how to use the telescopes and what they can look at.
Space scientist and SPA President Dr. Helen Walker sees that as a
great way to liven up science in schools. "The UK has a flourishing
community of amateur and professional astronomers. Through Telescopes
for Schools they can share their enthusiasm with our young people --
we hope to reach tens of thousands of pupils each year. We think
every pupil should have the chance to look through a telescope, an
experience to remember for the rest of their lives."


The 60-inch reflecting telescope that ushered in the modern age of
cosmic exploration has marked its 100th anniversary. When it was
commissioned on Mount Wilson, which overlooks the Los Angeles basin in
southern California, in 1908, the revolutionary 60-inch telescope was
the largest in the world and the first to explore (rather than map)
the Universe. It was the brainchild of George Ellery Hale, who
founded the Mount Wilson Observatory in 1904 with money from Andrew
Carnegie and was a pioneer in the then new field of astrophysics.
Acknowledged as the forerunner of every modern research telescope --
including the Hubble -- the telescope is now retired from active
science, but is the largest telescope available in the world
exclusively to the public for astronomical viewing. It took only four
years to build and was the first designed primarily for photographic
and spectrographic use. The observatory, with its telescopes and
solar towers 5,700 feet up in the San Gabriel Mountains, was once a
popular tourist attraction, but many people now seem unaware of its
existence and historic importance.

Science Daily

DNA studies on two strands of hair and a tooth have ended a centuries-
old hunt for the tomb of Nicolas Copernicus, the 16th-century
astronomer who shocked the world by declaring that the Earth was not
the centre of the Universe. The tests confirmed that remains found in
Frombork Cathedral in northern Poland in 2005 are those of the man
considered to be the father of modern astronomy. Born in Torun,
northern Poland, in 1473, the mathematician and clergyman is
celebrated for his heliocentric theory of the Universe.

Polish, French and German researchers have tried for two centuries to
find the tomb of Copernicus. He was a canon of Frombork, a Gothic
cathedral on the Baltic-Sea coast of Poland, and was thought likely to
have been buried beneath its floor. In 2005 archaeologists found the
remains of a 70-year-old man in the main Holy Cross altar of the
cathedral. The skull was taken to the Central Forensics Laboratory at
Poland's National Police Headquarters, where computer graphics were
used to create a facial reconstruction, which proved to be of an old
man who bore a striking resemblance to portraits of the young
Copernicus -- including a scar above his right eyebrow.

Recently, scientists have compared genetic material from two strands
of hair found in Calendarium Romanum Magnum, a book by Johannes
Stoeffler published in 1518 and owned by Copernicus for many years, to
a tooth from the skull found in Frombork. The two strands of hair
found in the book have the same genome sequence as the tooth from the
skull and a bone from Frombork. The Calendarium and other books that
once belonged to Copernicus were taken to Sweden during the
17th-century Polish-Swedish wars and are now held by Uppsala

Bulletin compiled by Clive Down

(c) 2008 the Society for Popular Astronomy

 Profile Send private message  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 1 post ] 

All times are UTC

Who is online

Users browsing this forum: No registered users and 0 guests

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You can post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group