Canberra
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Southern Cross - July 2001

• Circinus by Steve Crouch
• Dust Storms Break Out on Mars
• Shoalhaven Astronomers Visit Mt. Stromlo by Bob Higginson

Circinus

Steve Crouch

I have to confess that I forgot it was again my turn to do a Constellation of the Month (probably because of Mars). This month's constellation is therefore very abbreviated and considerably based on the Circinus notes in the second edition of Hartung's "Astronomical Objects for Southern Telescopes".

Circinus is quite easy to find, being adjacent to the two pointer stars, Alpha and Beta Centauri. It's very small and contains little of interest.

1. Double Stars

Firstly, h 3632 (13h 58.5m, -65° 48') is a good unequal pair (mags. 6.2, 10.0; sep. 6.4") with an orange-yellow primary and white secondary separable with 7.5 cm aperture.

Alpha Circini (14 42.5, -64° 59') is another unequal pair (yellow, red) with magnitudes 3.2 and 8.2 with a separation of 15.6".

Finally, Gamma Circini (15 23.4, -59 19) with whitish components of 5.1 and 5.5 separated by 0.83" would appear to require good seeing conditions for separation. Hartung claims that 20 cm aperture will do it.

2. Planetary Nebula

NGC 5315 (13 54.0, -66° 31') is a small bluish planetary nebula is only 5" across, so would require some magnification for certain identification without the use of an O III filter. I observed this with the C11 some years ago and merely remarked "small bright blue PN".

3. Galaxy

Given the proximity to the Milky Way, you wouldn't expect to find much in the way of galaxies here. There is one worth looking for, however. The Circinus galaxy (14 13.2, -65° 20'), although very much obscured, is detectable with 20 cm under a dark sky as a small elongated haze.

That's it for this month - I'll try and do better next time.

Dust Storms Break Out on Mars

Favorable oppositions of Mars always occur when Mars is high in the sky for observers in the Southern Hemisphere. This leads to southern observers having an unfair advantage over their northern counterparts: a large apparent diameter for the planet just when there is less atmospheric turbulence to peer through. In the current opposition, for example, Mars crosses the meridian in Canberra at an altitude of 81°. However, the seeing is also affected by the atmosphere of Mars, and it is an unfortunate fact that at favorable oppositions, when Mars is closest to the Sun and the planet's atmosphere receives more heat, dust storms are more common and can obscure surface features in particular regions or even globally. This opposition has been no exception. But to experienced observers well acquainted with the normal Martian surface markings, these phenomena can themselves be interesting to watch in progress.

Dust storm activity has recently been reported by many observers, including those attached to the Mars Section of the Association of Lunar and Planetary Observers (ALPO). On 24 June, dust was noticed over Hesperia, between Mare Tyrrhenum and Mare Cimmerium. The storm may actually have started in Mare Tyrrhenum, but cleared that region to form two streaks, one over Hesperia and one over eastern Hellas, which joined over Ausonia. Mare Cimmerium was still completely unaffected by the dust cloud on 27 June, but on 29 June a thick streak of dust coming from the south nearly divided it in two (see middle picture).

By 1 July, Japanese observers reported Mare Cimmerium as extraordinarily faint, covered with streaks of dust, and Electris to the southeast as bright with dust. This agrees with an observation by Albert Brakel on that date, using the Oddie Telescope at Mt Stromlo, that there was no sign of Mare Cimmerium even though Mare Sirenum next to it to the east was prominent; also, a thin long greyish streak latitudinally bisected the south polar hood.

Elsewhere on 29 June, a Singapore observer noted a "bright germ of dust" on the east coast of Syrtis Major, and Steve Crouch took a CCD image through his C14 that showed a dust storm in progress over Elysium and Amazonis, well to the north of Mare Cimmerium (middle picture). The dust cover was spreading rapidly.

By 2 July, the Japanese observed yellow dust over a broad region from Phlegra through Elysium to Aetheria, and extending south (Hellas to M. Sirenum) and north, covering much of the eastern hemisphere. The following night, another image by Steve Crouch showed the dust obscuring just about everything, but with the north polar hood still in view. Dust cover on this scale is rare, although there have been 3 global events in the late 20th Century.

Meanwhile, US observers were able to examine the opposite hemisphere. During 3-4 July, multiple dust storm centres were found over the Mariner Valley and the region to the south (Daedalia, Thaumasia, western Aurorae Sinus, Ophir, Tithonius), partially obscuring Solus Lacus and extending northwards into Tharsis. Activity extended to southern Chryse, north of Aurorae Sinus, on 5 July. These events may be similar to those in 1990, when multifocal storms occurred in this region.

[Compiled from various sources of information, including the ALPO Mars Observing Alert web page at www.lpl.arizona.edu/~rhill/alpo/marstuff/marsalert.html. The original color images by Steve Crouch can be seen on his website at www.pcug.org.au/~stevec/, along with examples of his other work]
1: A dust-free Mars on 17 June 2001, showing the polar hoods, clouds and haze on the morning and afternoon limbs, and Syrtis Major at right centre	2: Bright dust over Elysium and Amazonis, centre to middle right, north of M. Cimmerium and M. Sirenum, on 29 June. Note the bright dust streak almost bisecting M. Cimmerium	3: The virtually dust-covered eastern hemisphere of Mars on 3 July, with the north polar hood still visible.
CCD images of Mars through a C14 by Steve Crouch.

Shoalhaven Astronomers Visit Mt. Stromlo

Bob Higginson

For some weeks now, several members of the Shoalhaven Astronomical Club had been organising a trip to Mt. Stromlo, and to take the opportunity to use the Oddie Telescope. Two of our party of six had in the past year or so done the certificate training course required by the CAS in order to operate the 'scope, and they had been discussing at committee level the idea that they should lead an 'expedition to the mountain,' in order to view, among other things, the 'Red Planet', which was to be the jewel in the crown or perhaps the icing on the cake, or whatever.

At the April and May general meetings of the club however, only Club President Jack Apfelbaum, Treasurer and ticket-holder Frank Gross, co-ticket-holder Chris O'Hanlon, V-P. Dan Crowley and partner Kim Touzel, and this writer and committee member Bob Higginson, indicated that they would be willing to go.

The day/night chosen was Saturday May 26.

The 'plan' was to attack the mountain on three fronts simultaneously, from the east along the King's Highway, and from the west and northwest via Goulburn and the Hume Highway/Illawarra Highway.

~~~

The Saturday morning dawned bright and reasonably clear, though with a cold westerly blowing, but one which the group unanimously expected would keep the clouds at bay.

However, by the time Canberra's northern suburbs had been breeched and the bulk of Mt. Stromlo was in sight, the clouds had lowered and the Sun had been all but blotted out by ominous grey, stratus clouds, of the type which were not conducive to good viewing. At the Mountain itself, the top was immersed in the stratus, and things looked hopeless, yet still some in the party pressed on, even while the warmth and safety of places like the Downer Club or similar beckoned.

The visitors centre at Mt. Stromlo was the focus of much of the rest of the group, and one or two were most reluctant to leave its interior. Yet, with so much having been done and so many kms covered and taken by the party, the general consensus was that 'we must press on'.

The previous week had excellent weather with calm winds and light high cirrus, which, as most would know, often enhances viewing, and as 'luck' (?) would have it here was another Astronomy night going down the gurgler!

The dome housing the Oddie was in sight by 5:30 pm, and as the party was disembarking and moving provisions into its sanctuary from the convoy of personnel carriers and all-terrain vehicles, the fog and overcast conditions had turned to rain and then sleet, and conditions became just terrible. In fact, this writer thought seriously about decamping, but since he was a guest in the Preso's car, that was out of the question, much to his chagrin.

The Oddie Dome was opened and the sight that greeted us was one of amazement - amazement on two fronts: 1) The telescope was there alright and looking quite fabulous, and as those who had not seen it before marvelled at Man's ingenuity, and were really ecstatic at getting this close to such a wonder, we saw the second front: 2) Beetles! Tens of millions of them; no millions of squillions of them!

The beetles were all over the Telescope, the seating, the flooring and any other apparatus which happened to be in the confines of the dome.

They covered the walls, the ceiling, and the opening section of the dome itself, so that when or if the dome was opened, as some wanted to do on the spot, a torrent of these creatures would surely have rained down upon the hapless humans below.

Consultation with a field book that was found determined that the beetles were of the genus 'coccinellidae', species 'adalia bipunctata' [i.e. ladybird beetles-Ed.] and though harmless enough, were in every conceivable nook and cranny of the dome.

Sleep that night, which did come blessedly for all at some time later in the evening, meant having these 'things' wander over all ones gear, in ones ears, through ones hair, down the neck and even finding their way into the sleeping bags.

Several nights later, at home, this writer's wife looked down from her TV show to stop and stare at two of the blighters making their way across her plate of desert. Her brow knitted in a frown, she asked 'where did they come from?', but I blithely maintained my silence. It was better to continue to watch the ABC News than to try to explain.

~~~

Meanwhile, back at the Dome: The six of us got cracking (?) and attempted to clean up the beetles from the gears of the 'scope, and to sweep them up off the floor, but there's a saying somewhere in my brain that says something about a King Canute??

Three times the floors were swept in quick succession, and just as quickly the lady-birds came right back down again, as if to mock us with their sheer weight of numbers. The animal kingdom surely is most impressive when seen under these conditions.

Ticket holders Frank and Chris ran us through the intricacies of working the 'scope and there was then much debate on the wisdom or otherwise of opening the dome. Of course, it was by now raining quite heavily with visibility down to absolute zero, and so the rain outside actually put paid to any such thought. Thankfully we settled down to have a meal of sorts in the dome environs. The red wine brought by this writer had a remarkably soothing effect on his otherwise rapidly deteriorating behaviour, based on him not getting his 'driver' (and Pres.) to agree to a strategic withdrawal.

The night was a complete wash-out, and a total waste of resources and time - but being an astronomer used to arranging public viewing nights or school visits and having them clouded out or rained out, the trip was not viewed in its entirety as a disaster. The sight of the Oddie Telescope sitting in its housing in all its majesty, and being able to read some of the literature kept in the dome about the history of the 'relic' was worth the trip in its own right.

The group slept the night away, though dawn could come quickly enough for this writer, and with the dawn came an early rise and a quick clean-up and departure. As we drove down off the Mountain, of course we emerged in the light and eventual sunrise of Sunday May 27, which after a brief encounter with some errant clouds, soon burnt off to be as nice a day as one could want!

Nowra and Ulladulla had to be retaken and the group split up into its component parts and went on their ways. The weather on the coast had been fine though cold with some clear viewing time for most of the night. No rain fell in Ulladulla or Nowra!