Deep Sky Night Report - 26 August 2006

Ian Ogilvie

It was a perfect evening with 6 scopes being set up on the northern side of the Bobroff "shed".

A wide variety of objects were viewed by the assembled company, and I hope the following notes compiled by Patrick Purcell and myself will give the reader some feeling for what was a great evening.

The 'usual showcase objects' were viewed during the evening: Jupiter, the Jewell Box, Centaurus A, Omega Centauri, 47 Tucanae, M22, M4, M7, the Tarantula Nebula, the Swan Nebula, the Eagle Nebula, the Lagoon and Trifid Nebulae, the Eta Carina Nebula, and the Ring Nebula.

PLUS: Other planetary nebulae including the Saturn Nebula, the Helix Nebula, the Bug Nebula, the Dumbell Nebula, NGC 246, NGC 4361, NGC 6337.

And: Galaxies including NGC 253, NGC 55, NGC 300, NGC 4945, NGC 7793.

And: Globular clusters M13, and NGC 288 [The Takahashi 6-inch telescope was impressive as it included NGC 253 and NGC 288 in the same field of view.]

Speaking of the CAS Takahashi, since refurbishment earlier this month, the CAS Takahashi has been working hard with the Science Festival activities and it attended the CAS DSN on Saturday. John Blank drove it for most of the night, generally using the 40 mm SWA eyepiece, with and without a UHC filter (and sometimes when we could "steal" one, a 31 mm Nagler with OIII). With between 2.5 and 2.8 degree FoV (31N vs 40 SWA) and a dark site, it produced the most wonderful expansive fields. Some of the highlights for me with the Tak in this configuration were:

M8 and M20 together in the same FoV, particularly with UHC or OIII this gives you a wonderful sense of perspective and scale.

M17 and M18 together also gave the same effect. Magnificent!!

Antares, M4, Sigma Scorpii, NGC 6144 and surrounds in a single FoV!!

NGC253 and NGC 288 together on the same FoV. This gave you the big picture, then over to Peter's 20" to look at the core of NGC 253. Wow!! The 2 scopes really complimented each other.

M6 and M7 were wonderful, both clusters beautifully framed.

Eta Carina of course, 2.8 degrees, high quality optics, with and without filters from a dark site ................ no comment required!

The Veil Nebula. Couldn't quite fit it all into a single field of view, but with a filter, gave a wonderful perspective on this object.

Again, to observe it though the Tak first and then swap to the 20" for a detailed look was magnificent.

It was a great evening with great company. Many thanks to Peter for his hospitality. See you all at the September Deep Sky Night.

CAS Members' Malin Award Successes

Mike Sidonio and Steve Crouch were among the winners in this years' David Malin Awards for astrophotography. Mike won the amateur deep sky category with his Eagle Nebula entry, while Steve's Omega Centauri and IC 4628 entries in the same category each got an honorable mention.

The competition was held as part of the Central West Astronomical Society's AstroFest. Amateur astronomers and photographers from around Australia were invited to take part in the exhibition and to submit their astrophotos for consideration in the prestigious "David Malin Awards".

This year's competition had three categories of entry: Wide-field (camera shots), Deep Sky (telescope shots) and Solar System objects. The photographs were judged in two sections, one for amateurs and one for semi-professionals. The photographs were judged by world-renowned astrophotographer, Dr David Malin, without David being aware of the identity of the photographers.
The winners were presented with the "David Malin Awards" at a special Civic Reception held in the Coventry Room of the Parkes Shire Library and Cultural Centre in the presence of invited dignitaries, during the CWAS AstroFest on 15 July 2006.

The judged photographs were exhibited for the entire month of July in the CSIRO Parkes Observatory's Visitors Centre. The exhibition then began a tour of the country to selected venues beginning with Sydney Observatory in August, to be followed by Mt Stromlo Observatory, Ballarat Observatory, Melbourne Planetarium and Brisbane Planetarium. Last year, the exhibition was viewed by 40,000 people, with even more expected to view it this year. The images will feature in "Australian Sky and Telescope", "The New Sky and Space" and "Australian Photography" magazines. It was not just technical skill that was awarded. The prizes went to pictures that captured the beauty of the sky and the intrinsic interest of astronomy in an aesthetically pleasing manner.

Congratulations to Mike and Steve for their continuing achievement of excellence! The winners in the other categories can be found at http://www.parkes.atnf.csiro.au/events/astrofest/awards/.

CONSTELLATIONS OF THE MONTH - Pavo

Steve Crouch

The constellation for this issue is the far southern one of Pavo (the Peacock) between Telescopium and Octans. As this constellation is far from the plane of the Milky Way, the majority of the deep sky objects are galaxies, but there is one globular cluster, the beautiful NGC6752. NGC6752 is the outstanding object in Pavo, and any observer in a hurry who looked at only it would still go away well satisfied. Pavo also contains a faint planetary nebula, Hart/Tritton 6 (RA 17 51.8, Dec -60 23) that should be in the reach of larger telescopes. I have to confess that I did not have time to search for it myself, but perhaps someone out there can send in a report. My observations were conducted from a reasonably good backyard site with my 28 cm C11 using a 22 mm Panoptic eyepiece giving a magnification of 127x.

We start with a fairly easy galaxy, IC4662 (17 47.1, -64 38) near h Pavonis. I did not notice anything special about it except a slight elongation, approximately E-W. The next galaxy, IC4717 (18 33.3, -57 58), is somewhat more challenging at magnitude 14.5, but was nevertheless seen fairly easily as a small faint streak of definite E-W elongation. This object, in common with many of the other galaxies in Pavo, only has a catalogued photographic blue magnitude. Visually, it may therefore be a little brighter than 14.5.

Another brighter galaxy is NGC6684 (18 49.0, -65 11) at magnitude 11.4. It appeared as the familiar small, roughly circular patch with a prominent slightly off-centre nucleus and is located near the tip of an arrowhead-shaped grouping of five 6-7th magnitude stars. Probably the best known galaxy in Pavo, however, is the large barred spiral NGC6744 (19 09.8, -63 51). This galaxy photographs well, as the accompanying picture shows, but it is rather less impressive visually. The central bar is very bright but the surrounding structure has a fairly low surface brightness. I thought, however, that I could see suggestions of the outer spiral arms.
We then come to the previously mentioned globular cluster NGC6752 (19 10.9, -59 59). This beautiful object is unusual in that it seems to consist of two separate groupings of stars. The small core, resolved cleanly to its centre in the C11, is overlain by brighter stars, generally scattered but some forming streamers, giving the initial impression that this is a globular cluster embedded in a rich open cluster. An even brighter star to the south of the centre is the prominent double h5085 (mags. 7.7 and 9.2, sep. 2.8", PA 241º).

Galaxies often appear in tight clusters and Pavo is no exception to this. A good example is the grouping of NGC6769, 6770, 6771 and IC4842 (19 19.5, -60 39) located not too far away from NGC6752. These objects form a prominent chain, with IC4842 appearing to me to be the brightest but all are fairly similar with magnitudes ranging from 12.6 to 13.5.

Two challenging galaxies now. IC4866 (19 34.6, -61 09) has a blue magnitude of 13.9 and would probably be a difficult object in 20 cm. The C11 showed it as a very faint small patch without noticeable structure. Slightly fainter and of almost identical appearance is IC4887 (19 48.3, -69 35) at magnitude 14.1.

Next is IC5052 (20 52.1, -69 12) which is a particularly striking example of an edge-on galaxy. Although faint, it is pretty easy and appears as a quite large uniform streak without noticeable structure.

Finally in Pavo, for those who like anonymous galaxies, is ESO 107-G004 (21 03.6, -67 10). This is one of the brighter examples in the ESO catalogue and I saw it quite easily as a faint circular patch.