THE BEST LUNAR OCCULTATION OF A BRIGHT PLANET IN 2008
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.
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:
www.lunarobservers.comVIEWING THE ISS TOOLBAG
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: http://www.popastro.com/
HUBBLE OBSERVES EXTRASOLAR PLANET DIRECTLY
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.
BETA PICTORIS PLANET FINALLY IMAGED?
ESO
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.
RED SPIRAL GALAXIES
RAS
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 DETECT MATTER TORN APART BY BLACK HOLE
ESO
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.
INDIA'S MOON PROBE HITS MOON
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.
JUNO MISSION TO JUPITER
NASA
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.
LHC REPAIRS TO COST £14m
BBC
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.
1000 SCHOOLS GET FREE TELESCOPES
RAS
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."
MT. WILSON CELEBRATES TELESCOPE'S 100th YEAR
Topix
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.
HUNT FOR COPERNICUS' TOMB IS OVER
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
University.
Topic: Late November Astronomy News (Read 1909 times)