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Published
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The Binocular
and Telescope
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Binocular
and Telescope
55 York
Street, Sydney
NSW 2000Shop
55 York Street, Sydney NSW 2000
OCTOBER 2004
* Volume 232
www.bintel.com.au
the best
NEW ASTRONOMY MAGAZINE
SKY & TELESCOPE ‘AUSTRALIAN EDITION’
American Sky & Telescope
has announced plans to produce an
Australian version of its monthly
magazine, beginning almost
immediately. In a deal that has taken
almost a year to stitch together, local
company Paragon Media Pty. Ltd,
has agreed to produce eleven issues
per year with a percentage of local
content and local advertising.
Managing Director of Paragon, Ian
Brooks together with Publisher Todd
Cole have previous experience with
large-scale magazine production.
They are already lining up
experienced staff to help produce the
first Australian issue of the magazine
which should be on the shelves at the
newsagents in early December in
time for Christmas sales.
“We plan to help grow the market. “
says Ian Brooks. “Given the respect
this title receives, we are confident
that it will rapidly find a following
in astronomy and science circles,
then attract the attention of the
general public.” Sky & Telescope
has been published by Sky
Publishing in the USA since 1941 and
is a well-known market leader.
Current issue
of Sky &
Telescope
from the USA
VIRGIN ASTRONAUTS . . . BRANSON SIGNS DEAL WITH RUTAN
Sir Richard Branson announced in late September that the Virgin group has signed a deal
with Paul Allen and Burt Rutan. The effect of the agreement will be that a new company
Virgin Galactic will offer the world’s first commercial passenger flights into space.... possibly
within the next two or three years.
SpaceShipOne, (shown on the left with the Virgin logo superimposed) was funded by Paul
Allen, co-founder of Microsoft with Bill Gates. The design and construction was by aircraft
inventer Burt Rutan, famous for his revolutionary canard wing designs and in the use of foamcored fibreglass shapes for home-built light aircraft.
Rutan also designed the light aircraft Voyager, which circled the globe non-stop and
unrefuelled in 1987. Voyager took off from Mojave airport in California carrying two pilots,
Dick Rutan and Jeanna Yeager into the history books. It flew 42,200 km in just over nine days
and used approximately 3200kg of fuel. The aircraft itself weighed just 450kg due to the use
of carbon composites and other super lightweight materials.
Burt Rutan said, on the signing of the historic deal that he believed that the consortium
would be able to develop the finest suborbital operation system possible. The first flight of
SpaceShipOne, although not perfect, included several new technologies that address the cost
and safety of manned space flight. By designing a craft that uses its own wing and tail system
as a brake for slow re-entry into the atmosphere, Rutan avoided the problems associated with high-speed, high-temperature re-entry. The destruction of the
space shuttle Columbia and its crew of seven astronauts in February 2003 highlighted the potential for disaster in high speed re-entry.
SpaceShipOne makes second successful space flight . . .. . just !
SpaceShipOne made its second successful flight into space on September 29 from its base at the
Mojave desert, California. In front of a large crowd of onlookers the craft was carried aloft, slung under
the belly of its mothercraft, WhiteKnight. At an altitude of 17,000 metres the spacecraft was dropped
from WhiteKnight. Pilot Mike Melvill ignited the rocket motor, a hybrid system that uses Nitrous Oxide
as an oxidiser and hydroxy-terminated polybutadiene (HTPB or rubber) as the solid fuel. The craft
accelerated through the sound barrier on its ascent. Halfway into the ascent the craft began a slow roll
which developed into a rapid roll, causing anxiety in observers on the ground. It appeared for several
seconds that the craft was out of control. The motor was cut, the flight reverted to smooth climb and
SpaceShipOne coasted to 103 kilometres altitude, just over the limit required.
The craft then nosed over and deployed the tail as a drag device to slow its return. After a slow
descent the tail was reconfigured from the ‘shuttlecock’ position and glided smoothly down to a perfect
landing. No passengers were carried but an equivalent weight was loaded aboard to comply with the
Ansari X requirements. At a debrief after the flight pilot Melvill said, "At the top, I got a surprise, the ship
Mike Melvill waves after flight.
really spun up and did a little victory roll. We got a little bit of a rolling motion going,"" He believes that
he may have over-corrected, causing the wild gyrations. "That sort
of thing can happen at my age!". He added that SpaceShipOne " ... flies like a dream. It's
Les Sara
Les Sara
a real Burt Rutan special." At a news conference later, Melvill said the flight began normally but he probably touched the controls when he shouldn’t have.
Other than the pilot-induced problem the flight was normal. The spacecraft will probably be prepared for another flight within a week. If this is successful the
prize will be won, leaving a dozen other teams struggling in their wake to be second. However as they say, there is no prize for second place.
AMATEUR STRONOMERS X-RATED ON INTERNET!
We ourselves find this hard to
believe .... but it has happened! An
amateur astronomer forum on the
internet has had an “Adults Only”
rating slapped on it by Yahoo.
The group, which discusses
all manner of subjects related to the
use of telescopes has suddenly found
that it is restricted to ‘adults only’ and
have been unable to find out exactly
why this has happened.
There are suggestions that some of
the topics they discuss, “...piggyback
mountings... bare wiring... Uranus...
and other similarly disturbing ideas,
including very clear references to
“naked eye viewing...” have tripped
switched somewhere in the Yahoo
system which has moved the group
to an age restricted area from the
“science, astronomy, amateur space
area” they were in before.
Members have attempted to contact
Yahoo regarding this error but have
had no success as yet in rectifying
the mistake. We’d like to mention the
name of the group but we are advised
that, as this newsletter goes out to
schools, it is best to not reveal the
name in case the site is inundated
by young people intent on viewing
‘naked eyes’, ‘piggyback mounts’
and other unseemly devices.
We dare not take part in a perverted
attempt to lower the morals of our
teenagers and younger astronomers.
There is a backlash (maybe
we shouldn’t even use that word...)
as fundamentalists, creationists and
flat-earthers take up arms against
science. Television stations are
already being pestered to remove
scientific programs and anything else
involved in truth and reality.
It’s on till December! The great Tele Vue sale!
. . . . . . . . . . . . . . . . . . . . check the new lower prices at www.bintelshop.com.au . . . . . . . . . . . . . . . .
Watery skies; Mel explains ...........2
AstroSpeak; using the language...2
Star Map for October ...................3
Mick ‘n Don .......................... .......4
SUBSCRIBE TO THE
NIGHT SKY FOR $12
Receive your copy
every month for an
eyeful of sky news .
A plaintive cry for help has been
received from a budding
independent politician to fund his
campaign for election in the federal
seat of Cook. Graeme Strang has a
Celestron CM-1100 telescope that
gets little use these days as he spends
most of his days (and nights)
developing his interesting theories
on zero taxation replaced by a land
and resource rent. Anyone interested
in snapping up a large telescope or
hearing about a different method of
funding the nation’s activities could
contact Graeme on 02 9580 1491.
★ ★ ★
Graeme stood in the last election and
was beaten by a mere 41,536 votes
by the sitting Member Bruce Laird,
seven other cantidates and the
donkey vote.
★ ★ ★
After months of rumours the cat is
out of the bag. Sky and Telescope,
the American astronomy magazine
is to launch an Australian edition.
The Australian edition should be on
the streets by Christmas. We live in
interesting times.
★ ★ ★
Internet Telescope Forum classified
as “Adults Only”? I kid you not! It
has indeed happened. Well, what do
you expect when amateur
astronomers talk about “naked-eye
observing” ... “piggyback mounting”
and other questionable practises?
What are we coming to?
★ ★ ★
What with Full Moon and all . . . .
the doom and destruction crowd
became somewhat agitated at the
prospect of the world’s impending
destruction at the hands of asteroid
Toutatis. Maybe they are becoming
bored with their own cries of ‘wolf,
wolf’! You can only claim that the
world is ending a few times before
nobody will listen. See the
prognostications of one of
Australia’s predictors of doom and
gloom on Page 2. If she’d been right
just a few times there would not be
many of us left to read this.
★ ★ ★
When Harry Roberts, an amateur
astronomer announced that he could
detect ‘blue-shift’ on solar flares his
news was treated with scepticism.
Now however ......., see Page 4.
★ ★ ★
Greg Cantori, an amateur
astronomer in the Sydney region is
a long-term reader of this newsletter.
He claims to have read every issue
from the first in 1985.
He
complained that
his name has never
appeared in print
in the NIGHT
SKY. Well Greg,
here’s your 15
minutes of fame!
The Binocular and Telescope Shop, 55 York Street, Sydney. Tel: 02 9262 1344 web: www.bintel.com.au
‘STARGAZER’ BOOK LAUNCHED IN STORE
Spring has sprung! The warm
weather means that nights are not so M2 (NGC 7089) is a globular cluster
cold. October is the full last month lying 37,000 light years away. At
before daylight savings kicks in. magnitude 6.5, it can be easily seen
Now is the time to get out and enjoy in binoculars or small telescopes,
the last of the Winter constellations however to resolve the brighter stars
as well as some of the fainter Spring a telescope of 100mm or more is
constellations. One of the fainter and required.
NGC 7009 (the Saturn
most ancient constellations in the sky
Nebula) is a planetary nebula lying
is Aquarius.
Currently the Sun is in about 3,000 light years away. It
Aquarius from late February to early resembled the planet Saturn when
March, however in the future
Aquarius will one day contain
the vernal equinox (the point
Fomalhaut
when the Sun crosses into the
northern hemisphere each
year). This will not occur until
AD 2597 when the point will
Helix Neb
δ
move from Pisces to Aquarius.
Astronomically, this is very
important as the right
ascension
coordinate
measurements are taken from
ι
this point.
ζ
Aquarius is one of the
few constellations that has
carried a consistent mythical
theme across different
α
β
cultures. To the Greeks, the
constellation represented
Saturn Neb
Ganymede, a young shepherd
who was carried off by Zeus
M2
to be the wine-waiter to the
AQUARIUS
gods. The Babylonians saw a
man pouring water from a jar
and the Egyptians saw the figure as viewed through large aperture
Hapi, the god of the Nile, his urn telescopes. At 8th magnitude, it
appears as a blue/green ellipse and
symbolising good fortune.
Aquarius mostly consists of can be seen in telescopes 75mm or
relatively faint stars, with its brightest greater.
October also sees the return
star magnitude 2.9, thus making the
constellation harder to see in light of the annual Orionids meteor
polluted skies. However, Aquarius shower. Interestingly, this shower
was first recorded in 288AD by
has some dazzling sights:
Alpha (α) Aquarii is a yellow Chinese astronomers. Meteor
supergiant, shining at magnitude 2.9 showers are caused when the Earth
crosses the orbit of a comet and
and lying 760 light years away.
Beta (β) Aquarii is also a yellow encounters a trail of debris and dust
supergiant with the same magnitude left by the comet. Certain meteors
as Alpha Aquarii. Beta Aquarii is a showers can be attributed to
particular comets and the Orionids
little closer to us than Alpha.
Zeta (ζ) Aquarii is a well-known are associated with Halley’s Comet.
binary consisting of 2 white stars at Meteors are best seen after midnight,
magnitudes 4.3 and 4.5. Their orbital with the Orionids no exception. The
period is 760 years and currently they shower is active from October 2 until
are moving apart, making them an November 7. Maximum occurs on
October 21. However the Orionids
easy target for small telescopes.
M72 (NGC 6981) is a globular also experience many subcluster, however at 9th magnitude maximums that occur around this
and a distance of about 56,000 light date. The last two decades have
produced good rates of from 14 to
years.
NGC 7293, the Helix Nebula is the 31 meteors an hour which means that
closest planetary nebula to the Sun observations of this shower should
The Helix covers about a quarter of certainly be worth the effort. The
a degree of the sky, thus making it Orionids are usually bright and swift,
the largest planetary in apparent size. moving at approx. 66 km per second
In recent years Hubble Space with many leaving glowing trains.
telescope has taken close-ups Ensure you make the most of the
revealing small knots of molecular night hours this month and enjoy
gas dubbed “cometary knots” due to some of the Spring delights our
Universe has on show!
their appearance..
THE MILKY WAY
Left: Customers queue for sales and
refreshments at the B & T Shop .
Right: Professor Fred Watson busily
signing copies of his book .
Below: Nadia Douglass watches carefully as
Professor Fred Watson signs one of six copies
she bought.
Below: The book itself.
Cover depicts Atlas
holding up the sky
Dr Fred Watson’s new book “Stargazer, the life and times of the telescope”
was given a cheerful introduction to the book-buying public at The Binocular
and Telescope on 23rd September.
Fred was installed at a desk in the store in the late afternoon and sat
there chatting with customers, signing and inscribing copies of the book for
almost three hours! In the meantime amateur astronomers and book-buyers
from as far afield as the Blue Mountains chatted, consumed several bottles
of commemorative “Fred’s Coice” Cabernet Merlot and Semillon Chardonnay
and munched their way through trays of finger foods and sandwiches.
It wasn’t till 8.30pm when the last book was signed, the last Cabernet
Merlot quaffed and the last customer ushered out the door that Fred was
allowed some rest before being taken off for a well-earned dinner by Glen
Dawes of Quasar Publishing.
An eminently readable book, “Stargazer” will make an excellent
addition to the bookshelf of the person interested in the history of astronomy.
October 2004 * Volume 232 * Page 2
ASTRO-SPEAK
an observer’s
dictionary. . . .
More language from Jack Kramer’s
“Guide to Astrospeak, the amateur
astronomer’s dictionary”;
Cruise Control: a clock drive on a
telescope mount.
Dew dads: droplets of water that
form on telescope surfaces.
Dob Snob: an amateur astronomer
who considers Dobsonian telescopes
superior to all others.
Faint fuzzies: celestial objects
whose name begins with NGC, IC
or Messier.
Fuzzy friendly: a good dark sky site.
Fuzz finder: a person who prefers
looking at very faint objects.
Gotit!: An exclamation that indicates
that an observer has found a faint
fuzzy
Gunky: cloudy (the sky was .....)
MZero: When an observer can see
nothing.
Nailed it!: To definitely see a faint
fuzzy.
Diddly Squat’s Nebula: An empty
hole in the sky.
MACQUARIE
UNIVERSITY
ASTRONOMY
OPEN NIGHT
Saturday 23 Oct
6pm till 10pm
North Ryde
kids welcome !
CLOSE ENCOUNTER WITH ASTEROID
BUT WORLD DOES NOT END THIS TIME
Doomsayers have been busy claiming that the asteroid Toutatis could
possibly strike the earth causing mayhem, death and destruction. Wild claims
were made that NASA (why always NASA?) knew the risks but was refusing
to inform the world. As you are reading this we can confidently suggest that
Toutatis passed by the earth without inflicting casualties.
One doom-sayer, possibly a figment of somebody’s fevered imagination
is supposed to be an Australian, a Mrs Phipps-Earl. She is claimed to have
predicted late in 2003 that the following would occur in 2004:
“There will be four substantial earthquakes in Australia in the first five months
of this year, Victoria, New South Wales and South Australia. NT and central
Australia will have massive floods, many cut off completely. Northern Queensland will have several destructive
cyclones and two in the Gulf, three in Northern WA.
There will be a massing of sharks in Southern WA, many people attacked and many beaches closed. The bottom
corner of WA will have a heatwave with little or no rain. There will be a gold strike in WA, many travelling to WA
to make a fortune. South Australian grape crops for wine will be destroyed, one will be weather the other flying
locusts, worst in history. Melbourne will have an earthquake, storms and major flooding. There will be a mystery
illness, many taken to hospital. Sydney and North will experience an earth quake. Another major disaster in the
Blue Mountains and a disaster will occur in the Sydney underground train system. Fires and gas leaks in Sydney,
loss of water and power. Several States in Australia will experience substantial durations of loss of power and
telephone. Severe drought and bush fires in South-West Queensland. Yet floods in Northern NSW up to Brisbane.
Beaches washed away on Gold and Sunshine Coast.
Water rushing in from the ocean up the Brisbane River, flooding inner city area. Major scientific discoveries made
in Australia between now and August next year, three medical and one re space (the universe) which will involve
a complete change in thought. Labour will win the next election.” .................. well, we’ll soon find out!
Queensland amateur astronomer Eddie Trimachi took this impressive image of the Milky Way galaxy from Norma to Ophiuchus at the recent
Queensland Astrofest. Eddie used his SBIG ST-10 CCCD imager with a 50mm Asahi Pentax lens. The panorama is a composite of 28 images
laced together. Each image consists of six 5 minute exposures using a Ha 10nm Schuyler filter.
More details: [email protected]
The Binocular and Telescope Shop, 55 York Street, Sydney. Tel: 02 9262 1344 web: www.bintel.com.au
October 2004 * Volume 232 * Page 3
you can now shop on-line at www.bintelshop.com.au for astronomical telescopes
Mid-evening mid October 2004
The Moon’s appearance for the
month of October is shown thusly:
6th
6
th
Mercury is behind the un
early in the month. Later
it reaches the evening sky setting an
hour after the Sun.
Saturn is in Gemini and
makes a neat line with
Castor and Pollux. Look
for it around 3am in the North East.
Venus rises around 4am.
and is the brightest
object in the pre-dawn eastern sky.
.
Uranus is in Aquarius
high in the western sky.
Difficult to find.
Last Quarter
Moon at apogee
14th
New Moon
22nd
Perigee
23rd
First Quarter
28th
Full Moon
Ralph Baldwin proposed that lunar
craters were formed mostly by
meteor impacts in 1941. Most
astronomers at the time dismissed his
theory. They now agree with him.
Mars is too low in the
eastern dawn sky to be
seen easily. Patience!
Wait till Christmas for better views.
Jupiter is rising in the
bright pre-dawn sky at
the beginning of the
month. By the end of
October Jupiter is much more easily
seen, especially as brighter Venus is
now near the giant planet.
Neptune is high in the
West. Visually appears
as a faint blue-green dot
in telescopes.
Pluto is having a whale
of a time. Pollies are
throwing porkies to the chooks (to
mix metaphors) and Pluto is tearing
around snapping lying ankles as fast
as he can. Election time is great for a
drover’s dog .
Meteors are best seen after midnight,
with the Orionids no exception. The
shower is active from October 2 until
November 7. Maximum occurs on
October 21. However the Orionids
also experiences many submaximums that occur around this
date. The last two decades have
produced good rates of from 14 to
31 meteors an hour which means that
observations of this shower should
certainly be worth the effort. The
Orionids are usually bright and swift
with many leaving glowing trains.
Make sure you make the most of the
night hours this month and enjoy
some of the Spring delights our
Universe has on show! The Orionids
will be visible after midnight in the
East. Look for the group of stars
known as the ‘Saucepan’ or as some
people call it the ‘Shopping Trolley’
.
Want to see what has been
described by one observer as a
“celestial golf ball”? Located near
the Small Magellanic Galaxy is a
globular cluster of stars that goes by
the interesting name of 47 Tuc.
It can be found about fifty degrees
above the southern horizon near the
Small Magellanic Galaxy. Easy in
binocs!
The Binocular and Telescope Shop, 55 York Street, Sydney. Tel: 02 9262 1344 web: www.bintel.com.au
FIRST LIGHT FOR CAS MEADE LX200 GPS 14”
SCOPE
CANBERRA Astronomical
Macarthur Astronomical Society Inc: NSW
☎ (02) 4627 1424 Ian Cook.
[email protected].
Sutherland Astronomical Society Inc: NSW
☎ (02)9832 4082 Brett McMillan.www.sasi.net.au
Northern Sydney Astronomical Society Inc:
☎ David (02) 9876 6750
www.nsas.ozau.net
British Astronomical Association (NSW)
☎ 9398 9705 E. Cocking www.baansw.asn.au
The Astronomical Society of NSW.
☎ (02) 4572 1568. Adrian Saw. www.asnsw.com
The Western Sydney Amateur Astro Group Inc
☎ Dave Gault (02) 4754 4351
www4.tpgi.com.au/users/wsaag
The Hawkesbury Astronomical Society: NSW
☎ (02) 4572 1568 Adrian Saw .
The Wollongong Astronomy Club. NSW
☎ (02) 4261 9369 Paul Brown
The Illawarra Astronomical Society: NSW
☎ (02) 4276 3199 Peter McKinnon
Shoalhaven Astronomers: South Coast NSW
☎ (02) 4423 2255 Jack Apfelbaum
www.shoal.net.au~astronomy/index.html
The Astronomical Society of the Hunter: NSW
☎ (02) 4937 4664 Col Maybury
[email protected]
Newcastle Astronomical Society: NSW
☎ (02) 4950 0725 Allan Meehan
www.nas.org.au
Central West Astronomical Society, NSW
Alex Abbey: [email protected].
Port Macquarie Astronomical Association NSW
☎ (02) 6583 1933 Jim Daniels.
Grafton Astronomical Society, NSW
☎ (02) 6642 4130 Jeff Ashenden
Ballaarat Astronomical Society: Vic
☎ (03) 5332 7526 John Hastie
http://observatory.ballarat.net
Bendigo District Astronomical Society
PO Box 164 Bendigo Vic 3552 . Barry McPhee
Astronomical Society of Victoria Inc
☎ (03) 9888 7130. Linda Mockridge
www.asv.org.au
Latrobe Valley Astronomical Society Vic
☎ (03) 5174 6453 home.vicnet.net.au/~lvas
Astronomical Society of Geelong, Vic
☎ 0407 345 070 Frank Baker for details.
http://members.optushome.com.au/asog
Mornington Peninsula Astronomical Society,
☎ 0419 253 252 Richard Pollard for details.
Astronomical Society of Melbourne, Vic.
☎ 0412 - 318 125 Chris Ellis
[email protected]
Canberra Astronomical Society: ACT
☎ (02) 6288 7394 Diane Purcell.
Brisbane Astronomical Society: Qld
☎ (07) 3321 8511 Darryl Mitchell
www.bas.asn.au
www.ozemail.com.au/~nwilliams/bas
Southern Astronomical Society:Qld
☎ (07)5537 3852 Kevin Dixon.
www.sas.org.au
Astronomical Association of Queensland, Qld
☎ Peter Hall (07) 3378 1173 www.aaq.org.au
South East Queensland Astronomical Society,
☎ (07) 3844 7904 Dave Larkin.
www.powerup.com.au/~mcerlean/index.html
Ingham Amateur Astronomers Club
☎ (07) 4776 5773 Tracey Castles.
Bundaberg Astronomical Soc. Qld
☎ (07) 4159 7232 www.interwox.com.au
Redlands Astronomical Society Qld
☎ (07) 3822 5545 Ross Spence
Bundy Skywatchers (South-Central Qld)
☎ (07) 4159 9674 Karlene Galway
Astronomical Society of South Australia, SA
☎ (08) 8338 1231 Tony Beresford.
www.assa.org.au
Astronomical Society of Tasmania, Tas
☎ (03) 6244 3476 Laurie Priest.
www.ast.n3.net
Astronomical Society of Alice Springs N.T.
☎ (08) 8952 9817 Annette Green
Darwin Astronomy Group NT
☎ (08) 8945 9450 Phillip Smith
Gove Amateur Astronomers, NT
☎ 0417 601 490 Ian Maclean for information.
Astronomical Society of Western Australia, WA
(now incorporating Murdoch Astronomical
Society) http://aswa.info
☎ (08) 9299 6347 Val Semmler.
Astronomical Society of The South-West, W.A.
☎ (08) 9721 1586 Phil Smith.
Kim Rawlings, John Howard and Andrew White fire up the new Meade LX200.
Society had all its belongings
destroyed in the devastating fire that
raged through Canberra on Saturday
19th January last year. Their library,
records, computers and telescopes
were at Mount Stromlo and were
destroyed along with everything else
on the mountain.
Society members approached
Meade Instruments in the USA to see
if they could negotiate the purchase
of a new 10” or 12” telescope at a
reduced price. Meade contacted the
Binocular and Telescope Shop and
the upshot was that a brand-new
LX200GPS 14” telescope was
donated to the Canberra society on
the basis that it would be
permanently mounted in an
observatory where it could be used
for public education as well as for
the Society’s research purposes.
The telescope has since
arrived and been temporarily
installed in a dome where members
can come to grips with the
complexities of its operation.
Society members have been
buying books and other items to
make up for the loss of the library
that was reduced to ashes in the blaze
that levelled hundreds of homes and
almost every building and telescope
at Mount Stromlo. The new telescope
will be relocated to Mount Stromlo
when its new home is completed.
SEEING DOPPLER SHIFTS WITH Ha FILTERS! Harry Roberts
We have all heard of the effects
of “red-shift”, discovered in the early
sixties, whereby the light of distant
galaxies, and particularly quasars, is so
reddened by their recession velocity that
spectral lines located in the ultra-violet
become visible in white light photos.
Measurement of the red-shift allows the
recession velocity of the object to be
calculated; blue shifts of objects
approaching the earth are also recorded
The Lumicon H-alpha filter
has a pass bandwidth of 1.5 Angstroms
(A), and a 1 to 2 angstrom tuning range,
either side of the central emission line at
6563A . It came as a surprise to find (after
six months of observations) that the
Lumicon H-alpha filter was capable of
detecting both blue-shifts (often) and redshifts (occasionally) for high velocity
ejection events that occur on the surface
of the Sun.
Observing with the filter, the
user soon learns to recognise the dark
sinuous features appearing on the solar
surface, called filaments. These come in
two kinds, Active Region Filaments
(ARF) and Quiet Region Filaments
(QRF)1 . The smaller ARF’s are found in
clusters radiating from large sunspot
groups (Fig 1). Both mark the boundaries
between zones of different polarity.
Although normally stable, both kinds of
filament occasionally erupt, which causes
flaring. Just before they erupt they grow
dramatically darker (Fig 2), from grey
to dense black over half an hour.
Typically, around the time that
flaring begins near the filament (Fig 2),
the filament itself mysteriously
disappears (Fig 3).
The filament, of course, is a
real object, perhaps 100,000 km long,
containing millions of tonnes of matter;
and can’t just disappear. The erupting
filament, lifting off the Sun’s surface at
huge velocity, say 50 to 100 km/second
(~300,000 km/hr), has its H-alpha light
(at 6563 A wavelength) shifted to the blue
side of the band by the enormous speed
of approach towards the observer. This
shift is about minus1 Angstrom (A) for a
velocity of 50 km/sec, and minus 2 A if
the velocity of approach is about 100km/
sec.2 Since the pass band-width of most
filters is around 1 angstrom, the blue
shifted light will no longer pass the filter,
and the approaching filament is therefore
invisible.
The Lumicon filter permits the
observer to “tune” the filter by using a
fine pitch tuning screw, allowing a shift
of band width into the blue or red “wings”
of the H-alpha waveband. There, in the
blue “wing”, at 6562 or 6561A the
observer will see the previously invisible
filament (Fig 4). Of course, all other Halpha detail visible “on-band” is now
unseen, although sunspots remain visible.
In effect the observer is now viewing a
very narrow red part of the white light
Sun, as well as the Doppler shifted Halpha filament. Fig 5 shows how events
might appear if viewed side on.
This ability to “tune” into both
blue and red ”wings” of the 6563 H-alpha
band is a very desirable feature to have.
It allows the user to search for material
ejected towards or away from the
observer, such as material streaming
down onto the Sun’s surface in Post Flare
Loops, or the enigmatic Surges, that can
shoot backwards into the Sun!3 I suspect
this wide “tuning” range is not available
on competing sub-angstrom filters
although I have NOT been able to test
them. The sub-angstrom filters do
produce higher contrast views of static
surface phenomena.
It is important to note that the
Doppler effect can only be seen when the
ejected material approaches or recedes
from the observer along their line of sight.
The effect is best seen near the centre of
the Sun. Near the Sun’s limb there is very
little motion along the line of sight, and
no Doppler shift is seen. Doppler shifts
can be detected almost every time a
filament ejection and flare occur, but this
can require a lot of observing.
Direct observation of Doppler
shifts is heaps of fun! I’m sure Einstein,
who recognised the application of the
effect to light beams while working up
his Special Theory, would concur.
1
Zirin, H. “Astrophysics of the Sun”, Cambridge
Uni Press. P 266.
2
Pasachoff, J. Field Memorial Professor of
Astronomy, Ward College, personal comm.
3
Zirin, H “Astrophysics of the Sun”. p 299.
If you’d like your Society included, please
contact Mike Smith at (02) 9262 1344 or
[email protected] with information. We’ll
put your details in the above list.
Hey Don,
why you carryin’
that umbrella?
It ain’t rainin’.
Mick, that big asteroid
Toutatis
has me
worried.
They say
an umbrella
will protect
us against
asteroid
strikes.
Er, a man
can’t be too
careful.
Umbrellas also
protect you from
meteor
showers.
October 2004 * Volume 232 * Page 4
Bouncy Spring Quiz
QUIZ
Professor, His Eminence, Dr. Nervo
Shatterini BGB, reports that the
answers to the Winter Quiz are:
(1) background radiation
(2) Charon (3) Jupiter’s 11th moon.
(4) William Lassell (5) NearShoemaker spacecraft.
(6) Emission, reflection, dark.
(7) crater on Phobos (8) An
imaginary line joining centre of a
satellite to centre of the parent body.
(9) In a meteorite. (10) Tycho Brahe
(11) Fred Hoyle (12) 47 Tuc
(13) Vulpecula (14) Cetus
(15) on the Moon. (16) crust of a
planet or moon.
(17) Neutral hydrogen. (18) Ernst
Opik. (19) 1992 (20) 9,300km
So many answers! So many
mistakes! Best entry was from Kelly
Belford of Ermington NSW.
His Intrinsic Immenseness
now presents his Bouncy Spring
Quiz. Get to it quizaholics!
(1) In what direction does a transit
telescope move?
(2) Where is the largest known
caldera?
(2) Who or what was the Leviathan
of Parsontown?
(2) Who discovered the dwarf
companion of Sirius?
(2) What part of Africa is recorded
as a constellation?
(2) What is the cosmological
principle?
(2) What metal does flint glass
contain?
(2) Where did the largest known
stone meteorite fall?
(2) Seth Nicholson discovered which
moon?
(2) What type of asteroids are bright
and often slightly red?
(2) What was the diameter of
Newton's first telescope?
(2) Which constellation lies between
Cygnus and Andromeda?
(2) Vulpecula contains which object
you might see in a gymnasium?
(2) Who invented the Coude
telescope?
(2) How much moon rock did
astronauts bring back from the
Moon?
(2) Which ancient described a 'nebula
following the sting of the scorpion?
(2) In which year was the SOHO
spacecraft launched?
(2) Name an object in space that
relates to a young frog.
(2) What is a TLP
Answers please! Use a Search
Engine.... deduct two points! His
Honorific Holeyness asks you to
send your entry (plus a suitably large
donation for His Eminence’s Home
for Wayward Blondes to:
Prof. Shatterini c/- BINTEL, 55 York
Street, Sydney 2000 or by email to:
[email protected]
James Hardie shares, pollie promises
and other questionable sources of
filthy lucre are discouraged in favour
of Euros, US dollars or platinum
bars. Mars Bars would be nice too.
Remember, deduct points for
Googling or for Yahooing.
Night Sky is published monthly by
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55 York Street, Sydney NSW 2000.
Tel: (02) 9262 1344 Fax: (02) 9262 1884
Mike Smith Editor.
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