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The Volume 124 No. 2 February 2015 Bulle n Monthly newsle er of the
Astronomical Society of South Australia Inc
23 years of public nights at The Heights p.5 Curiosity detects methane on Mars p.7 The planets for February 2015 p.10 Comet Lovejoy put in a great show p.11 Deep Sky ‐ observing Thor’s Helmet p.14 Registered by Australia Post Bulle n of the ASSA Inc
Print Post Approved PP 100000605 1
Don’t miss Dr Graziella
Caprarelli speak on the
future of solar system
exploration at the
February General
Meeting!
Visit us on the web: February 2015
www.assa.org.au In this issue: ASTRONOMICAL SOCIETY of SOUTH AUSTRALIA Inc GPO Box 199, Adelaide SA 5001
The Society (ASSA) can be contacted by post to the
address above, or by e‐mail to [email protected]. Membership of the Society is open to all, with the only
prerequisite being an interest in Astronomy.
Membership fees are: Full Member
Concessional Member
Subscribe e‐Bulle n only; discount
$75
$60
$20
Concession informa on and membership brochures can
be obtained from the ASSA web site at:
h p://www.assa.org.au
or by contac ng The Secretary (see contacts page).
Member Submissions Submissions for inclusion in The Bulle n are welcome
from all members; submissions may be held over for later
edi ons.
ASSA Ac vi es Details of general mee ngs, viewing nights etc 3
Reports Repor ng on Society ac vi es 4
Ar cle Paul Rogers tells of 23 years of Public Nights 5‐6
Ar cle Curiosity detects Methane on Mars 7‐8
Astro News Latest astronomical discoveries and reports
9
The Sky this month Solar System, Comets, Variable Stars, Deep Sky 10‐14
ASSA Contact Informa on 15
Members’ Image Gallery A gallery of members’ astrophotos 16
Wherever possible, text submissions should be sent via e‐
mail or posted on CD‐ROM in almost any word processing
format and may s ll be submi ed handwri en or typed.
Your name may be withheld only if requested at the me
of submi ng. Images should be high resolu on and
uncompressed, e.g. TIFF file formats, although high
resolu on JPEGs are acceptable. Your full name and
object designa on must be provided with each image and
will be published. Equipment/exposure etc details are
welcome but op onal.
Adver sing & Classifieds Small adverts and classifieds are free for members (space
permi ng). Commercial adver sing is available at a cost
of $50.00 per quarter page per issue.
Members are reminded that addi onal files, links, and
resources will be avaibale on the ASSA website to
complement material published in The Bulle n.
All enquiries and submissions should be addressed to The
Editor and preferably sent by e‐mail to:
[email protected]
Colorado Springs Astronomical Society www.csastro.org
Important No ce Addi onal Online resources for The Bulle n Sister Society rela onships with: Orange County Astronomers www.ocastronomers.org
Central Arkansas Astronomical Society www.caasastro.org
For large files (e.g. on CD) or
hardcopy items, post to:
Joe Grida Editor, The Bulle n PO Box 682, Mylor SA 5153 Contribu ons should reach the Editor no later than the 7th of each month, for publica on in the following month’s issue of The Bulle n
Cover photo: Comet C/2014 Q2 Lovejoy, imaged by Micheal Ma azzo
Bulle n of the ASSA Inc
2
February 2015
Ac vi es February 2015 ‐ the month at a glance
General Mee ng What’s hot in planetary science Wednesday, 4 February, 2015
@ 8:00pm
Kerr Grant Lecture Theatre
2nd Floor, Physics Blg
University of Adelaide
North Terrace, Adelaide
An overview and the future of solar system explora on In the past few months several
successful missions to planets and
objects of the solar system have made
the news.
Exo c names such as Mangalyaan,
Rose a, Maven, have become common
Guest Speaker: knowledge, and the achievements of
Dr Graziella Caprarelli planetary scien sts and mission
Associate Professor in Space Science engineers have once again bounced to
the a en on of the general public.
University of South Australia
(See speaker bio on page 4)
Through an overview of a number of
significant results from selected
missions, this talk will map the current
scien fic knowledge of planetary
systems, and highlight probable future
The scien fic discoveries made by each areas of explora on, including their
new mission of explora on of the solar challenges.
system bring us closer to unravelling
Planning on going observing? Save yourself unnecessary travel and me. If the weather looks doub ul where you are, check with the following people to see if the event is s ll on (or see www.assa.org.au a er 5pm). Stockport Observatory (DO 3‐13)
Observatory 8528 2284
Lyn Grida 8388 5980
Tony Beresford 8338 1231
Heights Observatory (DO 3‐34)
Robert Bronca 8266 7504
Black Forest
the mechanisms of forma on and
evolu on of our planetary system,
provide clues to what extra‐solar
systems look like, and direct our search
for possible answers to the ques on of
how and where life originated.
Febuary 2015 Calendar Day Time Ac vity Wed 4
7:00pm
Beginners’ Mee ng
Wed 4
8:00pm
General Mee ng
Sun
8
2:30pm
Telescope Clinic, The Heights
Sat
14
8:30pm
Members’ Viewing Night – Stockport
Sat
14
8.30pm
Member’s Viewing Night ‐ Riverland
Sat
14
8:30pm
Members’ Viewing Night – Tooperang
Fri
20
8:30pm
Public & Members’ Viewing – NYP
Fri
20
8:30pm
Public Viewing Night – The Heights
Sat
21
8:30pm
Public & Members’ Viewing – Whyalla
Sat
21
8:00pm
Members’ Viewing Night – Stockport
Wed 25
7:30pm
ASSA Council Mee ng
Fri
27
7:30pm
Deep Sky Imaging Group
Fri
27
8:30pm
Public Viewing Night, Henley Square
Note: Times shown above and throughout this document are: 5 Oct 2014 to 5 Apr 2015 : South Australia Summer Time (UTC+10:30)
6 Apr 2015 to 3 Oct 2015 : South Australia Standard Time (UTC+ 9:30)
4 Oct 2015 to 3 Apr 2016 : South Australia Summer Time (UTC+10:30)
Greg Weaver 8293 2341
Whyalla Ernie Ernes 8645 3613
Tooperang Jeﬀ Lowrey 0429 690 610
Northern Yorke Peninsula
Tony Henderson 0429 352 382
Riverland Tim Vivian 0407 800 225
Bulle n of the ASSA Inc
Astronomy Educa on ‐ Beginners’ Talks Wednesday, 4 February, 2015 @ 7:00pm Kerr Grant Lecture Theatre University of Adelaide This month we explore the inner planets of the Solar Sys‐
tem from Mercury to Mars. These are the
rocky planets which are similar to the Earth
in composi on. We also look at the new
class of Dwarf planets which include Pluto,
Ceres and Eris.
3
February 2015
Reports and No ces Reports on recent ASSA ac vi es, and no ces of upcoming events
Guest Speaker Biography Have you done your Police check yet?
February 2015 General Mee ng You may recall that ASSA published a no fica on in the
January 2014 Bulle n regarding Police Checks. The no ce
advised all members that they will require a current Police
Check (clearance) Cer ficate if they par cipate as a
volunteer at any ASSA sanc oned public event. Although
this is yet to be made mandatory by parliamentary
legisla on, it was, and is now even more so in the light of
recent events, only a ma er of me before this will be
compulsory.
Dr Graziella Caprarelli Dr Graziella Caprarelli is Inaugural Associate Professor in
Space Science at the University of South Australia. Dr
Caprarelli obtained her PhD in Earth Sciences from the
University La Sapienza (Rome, Italy).
A er two post‐doctoral appointments in Japan, she moved
to Australia, first in Adelaide, and then to Sydney, where
she worked at the University of Technology Sydney un l
December 2013.
Regardless, ASSA is s ll bound by a duty of care under the
guidelines set by the Commissioner for Children, and also by
our Insurance provider who state this clearly in our
insurance policy. Consequently, ASSA Council passed a
mo on that has made this a Policy that "all ASSA members
who volunteer at any ASSA sanc oned public event hold a
current Police Check Clearance Cer ficate". We gave
ourselves un l the end of June 2014 for the majority of
member volunteers to have completed this Police Check,
but it would appear that quite a few members who kindly
volunteer their me at these events have yet to meet this
policy requirement.
To date she has conducted research and published on the
topics of volcanic processes on Earth and Mars, impact
crater sta s cs, and Mar an ancient climate. She
an cipates that her scien fic curiosity will lead her
towards expanding her areas of inves ga on to other
planets and objects of the solar system and beyond.
Please refer to the member's sec on on our web site for
the Instruc ons and Guidelines on how to apply for the
Police Check Cer ficate.
h ps://www.assa.org.au/media/58017/Police‐Checks‐
Process‐for‐Applicants‐ASSA‐version.pdf Alterna vely , please contact Paul Rogers directly by email
and he can email you the guidelines as well as the
applica on form.
[email protected]
Telescope clinic Please note that there is NO FEE to do this, as ASSA has
been granted a V.O.A.N. number that means we don't pay
for members who volunteer, to have this check done.
Did Santa bring you a new telescope for Christmas? Or has your telescope languished in the garage or shed because you didn’t know how to set it up? Is something not quite right with your telescope? Out of collima on? Get answers to all these ques ons, and many more at the first Telescope Clinic of 2015. Get your copy now, and be prepared for 2015. Available at the General
Mee ngs or by mail order.
$23 + $4 postage
The Heights Observatory Sunday, 8 February 2015 2:30pm Bulle n of the ASSA Inc
Email [email protected] to place your order. 4
February 2015
Well, …..that was fun! Paul Rogers recounts his 23 years as co‐ordinator of The Heights public viewing nights
As most of you know, I’ve handed over the reigns as the co‐
ordinator of the public nights at The Heights to the willing
and capable Robert Bronca – who has also been elected a
Council member for 2015.
Robert, together with his partner Corrie and their children,
have been assis ng at The Heights regularly for some me.
Please con nue to support Robert with the public viewing
nights, just as many members have supported and assisted
me over many years.
In fact, on behalf of ASSA, I have been co‐ordina ng and
“running” the public nights at The Heights for 23 years, so
with other developments looming (family, grandchild
coming, re rement etc), I decided it was me to step back a
li le and encourage others to have a turn.
It’s hard to believe I have been doing this for 23 years, but
when I think about it and “look back” there are certain
memories and reminders that do indeed indicate the me
has passed.
Here’s a few snippets from those 23 years.
When I started, the Emanuel Papaelia domed observatory
was newly constructed, there were no fences around The
Heights school, and the 2nd Observatory – The Inghams
Rooms was s ll 9‐10 years away from construc on. Under
Emanuel’s guidance and encouragement, there was a very
ac ve student involvement, and it was not long before the
school was gaining recogni on and praise for its forward
thinking in science and especially, astronomy.
Accurate records for some of these numbers (public and
members) weren’t kept in the first few years, but from 1994
onwards to December 2014 this is what happened……
The regular monthly public nights also soon became well
known, both in the local area and more broadly thanks to
various publica ons that gave advanced no ce of these
nights. The first public nights were run by members such as
Joe & Lyn Grida, Trish Ellin and Manuel Papaelia, – Joe Grida
s ll writes regular ar cles for the Adver ser, and this has
been a con nuing source in adver sing these nights.
4,547 members of the public a ended at The Heights
assisted by 1,175 members – a lot of members on a regular
basis and some who are s ll coming to help since the start.
$11,054 was taken in cket sales. These numbers were
actually over 142 “go ahead nights” as there were another
137 nights cancelled. There was a 12 year period between
2004 to the end of 2012 when there were more
cancella ons than go aheads.
Students, with their parents, and also science teachers and
principals have all “moved on” since those early days, but
there has been a constant renewal of these people, some
with a passing interest, and luckily others with a more
enthusias c outlook and willingness to contribute and work
with ASSA to ensure the success of the facili es.
Anyway, enough of this boring stats stuﬀ. Some memorable
nights I recall…
Probably, the present me sees some of the strongest
involvement, with the current facili es and equipment a
reflec on of the dedica on and hard work by Andrew Cool
and by parents and the school – assisted at various mes by
ASSA members.
The only person I’m aware of that fell down the stairs – my
own daughter Claire when she was about 12 years old (now
32) – tried to get down quickly and uninten onally
succeeded by slipping and bouncing down every step on her
backside (she survived but was quite embarrassed).
So what happened at the public nights over the last 23
years?
Then there was the me the crea onist visited. Showed him
some distant objects that exceeded (in light me) his belief
Bulle n of the ASSA Inc
5
February 2015
Well, …..that was fun! Paul Rogers recounts his 23 years as co‐ordinator of The Heights public viewing nights
of the age of everything. He was quite ma er‐of‐fact in
in the dome (literally) when some idiots lobbed fireworks
sta ng that what he saw was fantas c, but couldn’t be there under my car that fortunately rolled out and oﬀ they went
at that distance!
sending colourful “stars” all over the dome, the me some
young girl guides embarrassed me (luckily it was dark), by
Who was at the oﬃcial opening of the Ingham Rooms
joining hands in a circle around me in the dome and singing
observatory and remembers the egg missiles lobbed on the a thank you song.
assembled dignitaries from some well hidden young
pranksters behind a neighbouring fence?
But probably best of all, are the comments of awe and
wonder from (especially young) people who have seen
And the rather inebriated young man that was becoming
something in the eyepiece that has really amazed them, and
very vocal on a very busy night – demanding that he have his their enthusias c responses are worth all the me and eﬀort
turn. I took on a new role that night in being Mr Policeman of the last 23 years.
and luckily he quietened down and did what he was told.
Of course, it goes without saying, ‐ and I’m not going to try
In a similar vein – David Benn and Michael Williams assisted and name them all – that none of these nights would have
in (last thing at night when everyone had le ) flushing out 3 been a success without all the help of many dedicated
young people that had broken into a school equipment shed members of ASSA who have – and s ll do – a end regularly
and were in the process of damaging the contents before we and make the experience for the public, one to remember
intervened and they were scared oﬀ.
and enjoy. Sadly some of those members who used to assist
are no longer with us, but I remember them all fondly.
There are many other memories…. The night I bogged the
Magna, the visit by a cycling club in the pouring rain, the
Thank you everyone for your contribu ons at The Heights
police oﬃcer who snuck up the stairs and gave me a fright
over the years that I represented ASSA as the co‐ordinator
for the public viewing nights …. it was fun.
when he challenged my (early by myself se ng up)
presence, and then stayed for some twilight views of Saturn.
(and, thank you Paul for the great work you did!... Ed)
the me the seismograph needle was going ballis c, and I
dismissed it as “local interference” – yes, egg on face, next
day an earthquake had been reported, the night I saw stars (Photos supplied by Andrew Cool).
Bulle n of the ASSA Inc
6
February 2015
Curiosity detects methane spike on Mars Dr Tony Phillips from Science@NASA reports on the latest discovery at Mars
Dec. 16, 2014: NASA's Mars Curiosity rover has measured a tenfold spike in methane, an organic chemical, in the atmos‐
phere around it and detected other organic molecules in a rock‐powder sample collected by the robo c laboratory’s drill.
"This temporary increase in methane ‐‐ sharply up and then
back down ‐‐ tells us there must be some rela vely localized
source," said Sushil Atreya of the University of Michigan,
Ann Arbor, and Curiosity rover science team. "There are
many possible sources, biological or non‐biological, such as
interac on of water and rock."
been delivered to Mars by meteorites.
Organic molecules, which contain carbon and usually
hydrogen, are chemical building blocks of life, although they
can exist without the presence of life. Curiosity's findings
from analyzing samples of atmosphere and rock powder do
not reveal whether Mars has ever harbored living microbes,
but the findings do shed light on a chemically ac ve modern
Mars and on favorable condi ons for life on ancient Mars.
Researchers used Curiosity’s onboard Sample Analysis at
Mars (SAM) laboratory a dozen mes in a 20‐month period
to sniﬀ methane in the atmosphere. During two of those
months, in late 2013 and early 2014, four measurements
averaged seven parts per billion. Before and a er that,
readings averaged only one‐tenth that level.
"We will keep working on the puzzles these findings
present," said John Grotzinger, Curiosity project scien st of
the California Ins tute of Technology in Pasadena (Caltech).
"Can we learn more about the ac ve chemistry causing such
Curiosity also detected diﬀerent Mar an organic chemicals fluctua ons in the amount of methane in the atmosphere?
in powder drilled from a rock dubbed Cumberland, the first Can we choose rock targets where iden fiable organics have
defini ve detec on of organics in surface materials of Mars. been preserved?"
These Mar an organics could either have formed on Mars or
Above: This image illustrates possible ways methane might be added to Mars' atmosphere (sources) and removed from the atmosphere (sinks). NASA's Curiosity Mars rover has detected fluctua ons in methane concentra on in the atmosphere, implying both types of ac vity occur on modern Mars. Bulle n of the ASSA Inc
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February 2015
Curiosity detects methane spike on Mars Dr Tony Phillips from Science@NASA reports on the latest discovery at Mars
Researchers worked many months to determine whether
any of the organic material detected in the Cumberland
sample was truly Mar an. Curiosity’s SAM lab detected in
several samples some organic carbon compounds that were,
in fact, transported from Earth inside the rover. However,
extensive tes ng and analysis yielded confidence in the
detec on of Mar an organics.
and were freed when SAM heated it, yielding informa on
about the history of Mar an water. The ra o of a heavier
hydrogen isotope, deuterium, to the most common
hydrogen isotope can provide a signature for comparison
across diﬀerent stages of a planet's history.
"It's really interes ng that our measurements from Curiosity
of gases extracted from ancient rocks can tell us about loss
of water from Mars," said Paul Mahaﬀy, SAM principal
inves gator of NASA’s Goddard Space Flight Center in
Greenbelt, Maryland, and lead author of a report published
online this week by the journal Science .
Iden fying which specific Mar an organics are in the rock is
complicated by the presence of perchlorate minerals in
Mar an rocks and soils. When heated inside SAM, the
perchlorates alter the structures of the organic compounds,
so the iden es of the Mar an organics in the rock remain
uncertain.
The ra o of deuterium to hydrogen has changed because
the lighter hydrogen escapes from the upper atmosphere of
Mars much more readily than heavier deuterium. In order to
go back in me and see how the deuterium‐to‐hydrogen
ra o in Mar an water changed over me, researchers can
look at the ra o in water in the current atmosphere and
water trapped in rocks at diﬀerent mes in the planet’s
history.
"This first confirma on of organic carbon in a rock on Mars
holds much promise," said Curiosity par cipa ng scien st
Roger Summons of the Massachuse s Ins tute of
Technology in Cambridge. "Organics are important because
they can tell us about the chemical pathways by which they
were formed and preserved. In turn, this is informa ve
about Earth‐Mars diﬀerences and whether or not par cular
environments represented by Gale Crater sedimentary rocks
were more or less favorable for accumula on of organic
materials. The challenge now is to find other rocks on Mount
Sharp that might have diﬀerent and more extensive
inventories of organic compounds."
Mar an meteorites found on Earth also provide some
informa on, but this record has gaps. No known Mar an
meteorites are even close to the same age as the rock
studied on Mars, which formed about 3.9 billion to 4.6
billion years ago, according to Curiosity’s measurements.
The ra o that Curiosity found in the Cumberland sample is
about one‐half the ra o in water vapor in today's Mar an
Researchers also reported that Curiosity's taste of Mar an
water, bound into lakebed minerals in the Cumberland rock atmosphere, sugges ng much of the planet's water loss
occurred since that rock formed. However, the measured
more than three billion years ago, indicates the planet lost
much of its water before that lakebed formed and con nued ra o is about three mes higher than the ra o in the original
water supply of Mars, based on assump on that supply had
to lose large amounts a er.
a ra o similar to that measured in Earth's oceans. This
SAM analyzed hydrogen isotopes from water molecules that suggests much of Mars' original water was lost before the
rock formed.
had been locked inside a rock sample for billions of years
Le : This graphic shows tenfold spiking in the abundance of methane in the Mar an atmosphere surrounding NASA's Curiosity Mars rover, as detected by a series of measurements made with the Tunable Laser Spectrometer instrument in the rover's Sample Analysis at Mars laboratory suite. Image Credit: NASA/JPLCaltech Bulle n of the ASSA Inc
8
February 2015
Astro News Interes ng news stories sourced around the world Researchers detect possible signal from dark ma er Scien sts have picked up an atypical photon emission in X‐rays coming from space, and say it could be evidence for the
existence of a par cle of dark ma er. If confirmed, it could open up new perspec ves in cosmology.
Could there finally be tangible evidence for the existence of
dark ma er in the Universe? A er si ing through reams of X
‐ray data, scien sts in EPFL's Laboratory of Par cle Physics
and Cosmology (LPPC) and Leiden University believe they
could have iden fied the signal of a par cle of dark ma er.
analyzing X‐rays emi ed by two celes al objects ‐‐ the
Perseus galaxy cluster and the Andromeda galaxy. A er
having collected thousands of signals from the ESA's XMM‐
Newton telescope and eliminated all those coming from
known par cles and atoms, they detected an anomaly that,
even considering the possibility of instrument or
measurement error, caught their a en on.
This substance, which up to now has been purely
hypothe cal, is run by none of the standard models of
physics other than through the gravita onal force. Their
research will be published next week in Physical Review Le ers.
The signal appears in the X‐ray spectrum as a weak, atypical
photon emission that could not be a ributed to any known
form of ma er. Above all, "the signal's distribu on within
the galaxy corresponds exactly to what we were expec ng
When physicists study the dynamics of galaxies and the
with dark ma er, that is, concentrated and intense in the
movement of stars, they are confronted with a mystery. If
center of objects and weaker and diﬀuse on the edges,"
they only take visible ma er into account, their equa ons
explains Ruchayskiy. "With the goal of verifying our findings,
simply don't add up: the elements that can be observed are we then looked at data from our own galaxy, the Milky Way,
not suﬃcient to explain the rota on of objects and the
and made the same observa ons," says Boyarsky.
exis ng gravita onal forces.
A new era
There is something missing. From this they deduced that
The signal comes from a very rare event in the Universe: a
there must be an invisible kind of ma er that does not
photon emi ed due to the destruc on of a hypothe cal
interact with light, but does, as a whole, interact by means of par cle, possibly a "sterile neutrino." If the discovery is
the gravita onal force. Called "dark ma er," this substance confirmed, it will open up new avenues of research in
appears to make up at least 80% of the Universe.
par cle physics. Apart from that, "It could usher in a new era
in astronomy," says Ruchayskiy. "Confirma on of this
Andromeda and Perseus revisited
discovery may lead to construc on of new telescopes
Two groups have recently announced that they have
specially designed for studying the signals from dark ma er
detected the much sought a er signal. One of them, led by
par cles," adds Boyarsky. "We will know where to look in
EPFL scien sts Oleg Ruchayskiy and Alexey Boyarsky, also a
order to trace dark structures in space and will be able to
professor at Leiden University in the Netherlands, found it by reconstruct how the Universe has formed."
Video: h ps://www.youtube.com/watch?v=aogKkzESbgs&feature=youtu.be
Story Source: Ecole Polytechnique Fédérale de Lausanne. "Researchers detect possible signal from dark ma er." Science‐
Daily. 11 December 2014. www.sciencedaily.com/releases/2014/12/141211115520.htm
Le : Could there finally be tangible evidence for the existence of dark ma er in the Universe? A er si ing through reams of X-ray data, scien sts in EPFL's Laboratory of Par cle Physics and Cosmology (LPPC) and Leiden University believe they could have iden fied the signal of a par cle of dark ma er. Credit: Image courtesy of Ecole Polytechnique Fédérale de Lausanne (screen shot from video) Bulle n of the ASSA Inc
9
February 2015
Solar System Highlights by Joe Grida
The major planets during February 2015
There are 2 brilliant beacons in our night sky this February.
Venus in the west, and Jupiter in the north‐east.
1.2. Combine that with its proximity to the western horizon
soon a er sunset, and it is really too hard to observe.
Mercury is a morning object this month, and reaches its
greatest elonga on west of the Sun (27o)on the 24th of
February. At the start of astronomical twilight at 5:30am
ACDT, you’ll find the li le mag 0.1 planet in Capricornus, just
7o above the eastern horizon.
Jupiter, the colossus of the solar system, comes to
opposi on on February 6th, so it is visible from dusk un l
dawn. During the first half of February, it retrogrades from
Leo back into Cancer, its brightness peaking at magnitude –
2.6. Its equatorial diameter is 45 arc‐seconds, so once Jupiter
is high in the sky on a night of steady atmosphere, a good
medium‐size telescope will reveal dark belts, light zones, and
hints of luxurious details within them. Jupiter is at a fairly
high northern declina on during this appari on, so it never
really rises more that about 40o above the horizon.
Venus dominates the western evening sky. It shares the
constella on of Aquarius with Neptune and Mars. On
February 1, the planet shines at magnitude –3.9, and
displays an almost full disk of 11.1 arc seconds, at a distance
of 1.5AU. It has a close encounter with Mars on the 22nd at a
distance of only 0.4o. They will make a good colour contrast
in binoculars. With Mars shining at just mag 1.2, it is 100
mes fainter than Venus! The night before, the thin crescent
Moon joins Venus and Mars in the twilight for a great photo
opportunity.
Saturn rises around 1:30am ACDT at the start of February,
and midnight at the end of the month. You’ll find the
glamour‐puss of the solar system si ng on the head of
Scorpius. It shines at magnitude +0.5, and its equatorial
diameter is only 16″. Even at a distance of 10.3AU, it s ll
manages to look larger than Venus, nearly 7 mes closer! A
Mars starts the month in Aquarius, but crosses the border telescope shows its gorgeous rings. They are lted almost
into Pisces on the 11th of February. The red planet has a ny 25° from an edgewise presenta on, prac cally the most
diameter of 4.2 arc‐seconds, and shines at a magnitude of
open they ever become (27o).
Dairy of phenomena February 2015 d
1
3
4
5
6
6
9
11
12
13
14
15
17
18
19
19
20
21
21
22
24
25
25
26
27
h(UT)
17 Venus 0.8oS of Neptune
23 FULL MOON
5 Jupiter 5.0oN of Moon
5 Regulus 3.8oN of Moon
6 Moon at apogee
18 Jupiter at opposition
19 Spica 3.2oS of Moon
8 Mercury stationary
3 LAST QUARTER
0 Saturn 2.1oS of Moon
16 Moon furthest South (-18.4o)
23 Pluto 3.0oS of Moon
5 Mercury 3.4oS of Moon
23 NEW MOON
7 Moon at perigee
10 Neptune 3.6oS of Moon
23 Venus 2.0oS of Moon
0 Mars 1.5oS of Moon
22 Uranus 0.3oS of Moon
5 Venus 0.4oS of Mars
19 Mercury greatest elong W(27o)
17 FIRST QUARTER
23 Aldebaran 1.0oS of Moon
4 Neptune at conjunction
7 Moon furthest North (18.3o)
Bulle n of the ASSA Inc
Uranus is some 4° above and to the right of Venus at the
end of the month, pre y low for finding a 6th‐magnitude
speck in the a erglow of sunset. Uranus will pass close to
Venus on March 4th.
Neptune starts the month near Venus, but at 8th magnitude
it’s very diﬃcult to see in the evening twilight. It’s invisible
the rest of the month, going through conjunc on with the
Sun on February 26th.
Happy observing!
Moon Phases ‐ February 2015 10
February 2015
Southern Hemisphere Comets by Michael Ma azzo
A roundup of bright and telescopic comets visible for southern hemisphere observers
Comets in 2015 Unless you are visi ng Northern Australia or parts further north, the comet Lovejoy show is over. Let us take a
look at what's ahead for 2015, including another 2 poten al naked eye comets!
C/2014 Q2 Lovejoy As of wri ng this in mid January, the comet was an easy
naked eye object in the northern evening sky a er sunset.
It peaked at magnitude 4.0, with an ion tail traceable to 7
degrees in length photographically, as it passed by Earth on
January 7 at 0.47AU.
Visually the ion tail was only a couple of degrees long and
required a dark sky to see it well.
The coma size was a whopping 25 arcminutes, almost as
large as the Moon, with a bright stellar "nucleus" in
telescopes.
The ion tail dynamics were a treat to photograph,
with frequent mul ple streamers and disconnec on events
on oﬀer.
Disconnec on events are caused by solar wind striking the
comet, stripping the ion tail away from the nucleus.
A new ion tail rapidly replaces the old one.
10P Tempel
Was discovered in 1873 as a 9th magnitude object and has
an orbital period of 5.5 years.
The appari on in 2015 is an average one, with the comet
closest to the Earth on May 24 at 1.31AU whilst arriving at
perihelion on November 14 at 1.41AU.
It will be observable as a magnitude 10 object in the
constella on of Ophiuchus, during October‐November
evening skies.
Very interes ngly, this comet displays a fine dust "trail",
detectable in CCD images.
22P Kopﬀ Was discovered in 1906 as an 11th magnitude object. The
perihelion distance was at 1.70AU.
Following an encounter with Jupiter in 1942, its period was
Above: A wide field photo by Michael Ma azzo, taken on 11 January, 2015 showing Orion, Taurus and the comet. 3x30 second exposure with a 50mm lens Bulle n of the ASSA Inc
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February 2015
Southern Hemisphere Comets by Michael Ma azzo
A roundup of bright and telescopic comets visible for southern hemisphere observers
reduced to 6.4 years and
perihelion decreased to 1.5AU.
This year the comet is closest to
the Earth on April 27 at 1.39AU,
then closest to the Sun on October
25.
The appari on is not very
favourable but it will be brightest
in October as a magnitude 10
object in the constella on of
Ophiuchus, in the same vicinity
as 10P Tempel.
An encounter with Jupiter in 2026
will further reduce the perihelion
distance to 1.31AU, and again in
2038, to 1.18AU. Very interes ng
mes ahead for this comet!
67P Churyumov‐Gerasimenko Above: Comet Lovejoy imaged by Jeﬀ Lusher at Eudunda on January 16, 2015.
Was discovered photographically
in 1969. The Rose a spacecra ,
now orbi ng 67P, will have prime seat for viewing the
comet approaching the Earth on 2016 January 16 at 0.72AU.
comet as it arrives at perihelion on August 13 at 1.24AU.
Because this object is a dynamically new one ( first
passage), it is more than likely to fizzle and fall below
It should peak at magnitude 10 in late September for us
expecta ons, but me will tell!
Earthbound observers. Unfortunately the observing
C/2014 Q1 PANSTARRS circumstances are not very good, with the comet situated
A bright southern comet!
low in the morning sky in the constella on of Gemini.
88P Howell Was discovered in 1981 and has an orbital period of 5.5
years.
With a perihelion distance of 0.31AU on 2015 July 6, this
comet has the poten al to reach magnitude 3.
Unfortunately it is at low solar elonga on, but moves
It is closest to the Sun on April 6 at 1.35AU and closest to the suﬃciently far away from the Sun by mid July to be visible,
low in the western evening sky in Cancer, fading from
Earth on October 3 at 1.33AU.
magnitude 4.
An encounter with Jupiter in 1978 reduced the perihelion
Although the appari on is unfavourable, the big plus with
distance from 1.9 to 1.3AU, and the comet has been very
C/2014 Q1 is that it is a returning visitor, with an orbital
ac ve of late.
period of 38,000 years.
Although not a favourable appearance, the comet is
The comet has been baked by the Sun on previous
expected to peak at magnitude 9 during April‐May in the
encounters. If this is the case, the currently dormant comet
morning sky, situated in Aquarius.
will switch on as it reaches the ice mel ng line (at 2AU this
April) and has the poten al to be considerably brighter than
C/2013 US10 Catalina Arrives at perihelion on 2015 November 15, at a distance of predicted!
0.82 AU. It will be very favourably situated in southern
hemisphere evening skies during October, where it may be a See my southern comets website for latest informa on and
photos:
faint naked eye target at magnitude 4 or 5. The
comet moves into solar conjunc on during November's
h p://members.westnet.com.au/mma /sc.htm
perihelion passage, then re‐appears in late December's
morning sky.
I can be contacted at mma @westnet.com.au
Unfortunately, Northerners are then favoured, with the
Bulle n of the ASSA Inc
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February 2015
Variable Vagaries by David Benn This regular column will cover happenings in the ever‐changing world of variable stars.
Over the last few weeks,
other than the usual fes ve
silliness and a emp ng some
images of comet C/2014 Q2
Lovejoy, I spent more me
characterising my Canon
1100D DSLR, in par cular
finding suitable combina ons
of ISO, f‐stop, and exposure
me for stars of various
magnitudes.
The plot shows so‐called
instrumental magnitudes on
the ver cal axis and exposure
me in seconds on the
horizontal axis. Each point
corresponds to a brightness
measure of a single star from
a single image where the star
is labelled as having a
par cular (rather bright)
magnitude, e.g. Mag 4.6, or
Var.
In this example, the la er
indicates a variable star (brightest star at lower right in
image below) whose brightness is bracketed by two
comparison stars; more comparison stars would be used for
an actual photometry measurement intended for
submission. Instrumental magnitudes are brightness values
measured directly from a DSLR RAW image. These vary
across camera/so ware combina ons and would ul mately
be converted to standard magnitudes. We’ll talk about that
in a future instalment.
Moving from le to right, brightness values trend further
nega ve, corresponding to sampling from an overall brighter
image due to longer exposure mes.
I’ll con nue to experiment!
On a diﬀerent front, in a week or two I should have a light
box with which I can create proper flat frames so I can start
to think seriously about doing photometry as opposed to
just ge ng ready to do so.
Links: h ps://dbenn.wordpress.com/2015/01/06/more‐c2014‐q2‐
lovejoy‐images
There is a more or less linear change in such brightness
values across images star ng at the upper le of each star’s
series. The further right and downward, the more we
approach camera sensor satura on. If we intended to use
such images for photometry, we would need to use images
for which satura on had not occurred, in this case, the first 2
or 3 images (1, 2 or 4 seconds).
These plots are probably complicated by the fact that the
images were taken on a fixed tripod, so untracked. The
radius of the photometry aperture used to measure the
magnitude was the same for each image, which may be less
than ideal for the last couple of images where trailing is
more prominent. The main point remains however: star
images that are saturated cannot be used for photometry
since they will not represent the true value of the star’s
brightness.
Bulle n of the ASSA Inc
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February 2015
Alone in the dark A guide to observing faint fuzzies in our night sky
by Joe Grida
Observing Thor’s Helmet in Canis Major One of my favourite summer me targets is NGC 2359 in
Canis Major. Also known as Thor’s Helmet, it is located 8.9
degrees north‐east of Sirius.
observing this with a 50mm refractor. Renowned deep sky
observer, Steve Go lieb writes:
NGC 2359 is a wind blown bubble powered by the extremely
massive and unstable Wolf‐Rayet star HD 56925. These types
of stars (only about 300 are known presently) represent a
late evolu onary phase of massive O‐type blue giants which
have become unstable in the late stages of their short stellar
life. WR stars heavily influence the surrounding interstellar
medium.
NGC 2359 consists of two dis nct components. The outer
component is a "U" shaped diﬀuse HII region of illuminated
gases ejected at an earlier me by the O type progenitor of
the WR star. The inner component is the central filamentary
bubble blown more recently by the winds of the WR star HD
56925. The stars get their name from the French
astronomers Georges A. Rayet (1839‐1906) and Charles J.
Wolf (1827‐1918) who first reported their existence in 1867.
See this ar cle on Wikipedia for more informa on:
h p://en.wikipedia.org/wiki/Wolf%E2%80%93Rayet_star
So, what is it like to observe. It responds well to small
telescopes as well as large ones. I’ve seen reports of people
"Thor's Helmet is a remarkably bright, detailed nebulosity at 100x using an OIII filter. The central region is a 5' bubble (illuminated by a Wolf-Rayet star) with a brighter rim along the west side giving a "C" appearance with irregular knots, filamentary wisps of nebulosity and areas of thinner nebulosity in the interior. A number of fainter stars are superimposed in the central region along with some brighter mag 11 stars on the north por on of the rim. A ached at the south end is a brighter 4' extension elongated towards the west with a mag 9 star at its SE side. This sec on then thins out into a long 10' streamer which precedes the main sec on and forms the southern "horn" of the helmet. A second long, thicker streamer is a ached at the north end of the central mass and extends out to the NW (this piece is also catalogued as IC 468). A fainter strip of nebulosity also begins on the north end and extends 10' due east while weak nebulosity is also east of the central helmet oﬀ the south side”. You do need dark skies to observe this surreal object. And
the OIII filter is mandatory as well.
Above: NGC 2359 (Thors’ Helmet) imaged by Paul Haese at Clayton Bay, SA. Equipment ‐ GSO 8" RC, with QSI583WSG
CCD. Guiding ‐ Takahashi TSA102 and Orion Star Shoot Autoguider. HaLRGB ‐670 220 220 220. Darks, flats and biases ap‐
plied. Processed in CCD stack and Photoshop CS
Bulle n of the ASSA Inc
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February 2015
Contact informa on Here’s how to contact various members of Council, Regional Co‐ordinators and SIG’s
2015 COUNCIL President & Public Oﬃcer Vice President Secretary Assistant Secretary Treasurer Editor Publicity Oﬃcer Observatories Director Technical Informa on Oﬃcer Instrument Oﬃcer Librarian Beginners’ Councillor Councillors Joe Grida
David Benne
Peter McKeough
Phil Stephen
Philip Pudney
Joe Grida
Paul Curnow
Lyn Grida
Dr Tony Beresford
Paul Haese
Susan Baker
Colin Hill
Greg Weaver
Robert Bronca
Steven Saﬃ
Lina Raslan
Stephen Scheer
(08) 8391 5377
0419 419 552
0418 688 654
(08) 8356 6936
0408 818 839
(08) 8391 5377
0402 079 578
(08) 8391 5377
(08) 8338 1231
0408 808 390
(08) 8524 3634
(08) 8523 0211
(08) 8293 2341
(08) 8266 7504
0431 585 014
0434 580 212
0423 702 975
[email protected]
vice‐[email protected]
[email protected]
assistant‐[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
steven.saﬃ@assa.org.au
[email protected]
[email protected]
Honorary Life Members: Ian Anderson, Ian Bedford, Dr Tony Beresford, Trish Ellin, Joe Grida, Lyn Grida, Colin Hill, Blair
Lade, Paul Rogers, Michael Williams, Mick Wolf.
Note: To address all members of the ASSA Council, send email to: [email protected] REGIONAL GROUPS Whyalla The group meets on the last
Wednesday of the month; and
public viewings are held monthly.
Coordinator: Ernie Ernes
Ph: 8645 3613
Email: [email protected] Northern Yorke Peninsula The NYP’pers hold combined mem‐
bers’ and public viewing nights
monthly.
Coordinator: Tony Henderson
Ph: 0429 352 382
Email: [email protected] SPECIAL INTEREST GROUPS Deep Sky Imaging Neil Walter
0418 805 182
Variable Stars David Benn
0407 261163
Radio Astronomy Peter Gray
0418 829 632
Light Pollu on Mar n Lewicki
0413 494 366
Aboriginal & Ethno Astronomy Paul Curnow
0402 079 578
Comets & Meteors Michael Ma azzo
0420 959 664
Planetarium Paul Curnow
0402 079 578
Society Historian Terry Wardle [email protected] OTHER CONTACTS Schools Viewing Nights Coordinator TBA
Webmaster Phillip Pudney
0408 818 839
[email protected] Awards Commi ee [email protected] Riverland The Riverland group hold com‐
bined members’ and public viewing
nights monthly.
Project Manager, Stockport Dome Replacement Project Co‐ordinator: Tim Vivian
Ph: 0417 800 225
Email: [email protected] South Australia Telescope (36”) Bulle n of the ASSA Inc
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Dean Davidson 0413 039 477 [email protected] [email protected] February 2015
Members’ Gallery Highligh ng members’ astrophotos
Above: Comet Lovejoy C/2014 Q2 imaged by Graeme Quinn on December 21 from Clayton, SA. Astro‐Physics EDF 130 GT
refractor, Canon 6D DSLR Camera, single 3 minute exposure, ISO 1600. Bright star near top le is Kappa Columbae, mag 4.4
Below: Narrowband image of NGC1760 in the LMC, by Paul Haese at Clayton Bay, SA. Takahashi FSQ106ED telescope &
QSI683‐8 CCD. SII Ha OIII 570 720 420(30 minute subs narrow band. Processed in CCD stack and Photoshop CS6
Bulle n of the ASSA Inc
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February 2015