2 nights under southern skies

[SAB]

Sunday May 25, 2008

The main objective last night was to view Jupiter, hoping for a view that I got the night before. It didn't take long for me to realise, that the seeing, despite every scenario being as good as freaking possible, was completely and utterly Rubbish. Only in Melbourne. Infact, it is typical of this area to have crud seeing in perfect setups. Just another fantastic trait of our desirable climate, ontop of the 180 annual cloudy days. I knew the seeing was Rubbish just by observing stars as they were flaring, jumping and were being smeared everywhere. Every clear night this winter so far, seeing seems to be horrendous. My best viewings were in summer. I know many like to say that best seeing occurs in winter. A big fat LOL to that. Not in Melbourne. It is not by accident that everyone bags our climate.

Not only that, at one point I was also interrupted by (unforcasted - typical) Melbourne cloud, but luckily that cleared after around 45 minutes.

Anyway, to the point. I set up the 12" dob at around 8.30pm and waited 2 hours for cool down while watching Wife Swap and Everybody Loves Raymond. Set up was a bit late and 2 hours wouldn't be enough for a dinner plate sized, 1.5 inch thick chunk of glass. The plan was to observe some open clusters and globulars while Jupiter rises, that'll also give the mirror a chance to cool down properly. Just a random selection of objects.

Scope: 12" F4.65 truss dob

Time: 10:30pm-1:45am

Seeing: 2-3/10

Temp: 6ºC

Harvard 6

Plotted as an open cluster in Musca in the HB atlas. Not alot could be seen at its plotted location. At 172x I could see 6 faint stars arranged in a cross with few others sprinkled about.

Harvard 8

Another alleged open cluster in Musca. All that could be seen at the supposed location is a diamond of 4 faint stars. There's nothing here to differentiate a would-be cluster from the background field. However, a short distance (2 FOVs at 172x) north lies a tiny trapezium of 4 stars with a further 6 arranged in a flattened "v" shape nearby. Maybe this is the real Harvard 8? Plotting error in the HB atlas perhaps?

LOD 757

Near the border of Musca and Centaurus lies this loose gathering. At 83x, I could see a line of 4 bright stars with a compact but sparse group of approx 15 fainter members located just to the north. Doesn't really stand out from the background field.

Rup 107

172x - same area of LOD 757, just a small faint loosely spread group of around 20 faint stars.

M20 - Trifid nebula

At 83x with the UHC filter I could just see the lanes, not bad considering the moon was just spitting distance away.

M8-Lagoon nebula

Again at 83x with the UHC, looked washed out for obvious reasons but could see a nice dark ribbon cutting across the nebula which made for quite a nice looking object. The brighter portion containing the Hourglass Nebula stood out well.

NGC 6153

This is a Planetary nebula located west of Zeta Scorpii. Rubbish seeing meant I couldn't use high mags. At 217x with UHC, it appeared as an egg-shaped patch of light, quite large aswell and I suspected annularity - which appears to be confirmed on photos. Showed up quite well despite moon glare. Forms a diamond with 3 adjacent bright stars.

NGC 6388

Globular cluster in Scorpius. At 217x (max possible on this night) there was no resolution although I could see 3 stars in its outer extremities, not sure if these were forground stars or actual cluster members.

NGC 6541

Another Scorpius globular. At 217x, it was largely resolved, perhaps 6/8th of the way in with 3 stars shining through the hazy, mottled core. Doesn't appear to have a tight condensed core. Very nice cluster, stood up well to the seeing. Infact it is one of the best globulars I've seen, after 47Tuc, Omega Cen, M22, the one in Pavo and the other one in Ara. Very nice and the background starfield makes it all the more nice!!! Kicks the Rubbish out of many M clusters Set in a nice rich field. Only need some good seeing to enjoy it fully.

M5

217x - seems to go suddenly from tenious outer regions to dense inner region. Almost fully resolved, innermost region appearing granular with a stellar core. I'd actually say that this cluster is no better than NGC 6541, although is perhaps a bit larger.

NGC 6210

Planetary nebula in Hercules. Very low down, but had it at 172x, with UHC. Appeared as a blue orb, but seeing really was crud and couldnt make out any features.

Saturday, May 24, 2008

Dank 1 / Dank 2

Apparently these are supposed to be a pair of open clusters (marked in the Herald-Bobroff atlas), located on the eastern edge of the coalsack. Nothing seen.

Stock 16

Open cluster not far east of Crux. Not alot seen, at 108x a small group of around 6 stars form an "A" shape. Pretty much a poor man's Jewel Box! A bright orange star lies near the cluster's eastern edge.

Basil 18

108x - loose collection of around 15 stars just east of Stock 16, with the 5 most prominent members arranged in a pattern reminiscent of the constellation Delphinus, with the head pointing east.

Lod 807

108x - another cluster adjacent to the Coal Sack. Sparse group barely stands out from the background star fields. A bright yellow star marks the northern extremity of the cluster. The brightest stars of this cluster are arranged in a perfect arrowhead outline. I thought that was pretty cool. It really is a perfect arrow! btw, it points south.

DY Crucis

That red star near Beta Crucis. Seems to have brightened and taken on more of an orange hue since the last time I saw it.

Homunculus Nebula

Scope has been cooling for a few hours by now and I was able to push it over 200x on the Homunculus. Bouts of good seeing revealed 2 'holes' in the major lobe, which also has a very irregular outline. The 2 spikes coming out of Eta Carina could also been seen.

M4

Very nice at 217x. Full resolution, higher mags make it look more like a rich open cluster! I spotted what appeared to be a ruddy coloured star near the northern end of the row that cuts across the clusters center. Not certain though, as its quite hard to make out colours in these faint stars.

M80

Outer areas of this globular were well resolved at 283x, quite nice but the seeing wasn't really great. Surprisingly I got slightly more resolution 326x, despite seeing. Also found this neat group of 4 stars while searching for M80, basically a nice golden double star with 2 other golden stars sitting on either side.

NGC 6309 - Box nebula

This PN showed up well despite moonlight. Used an OIII filter at 217x and I could see a tiny rectangular or ellipsoidal object with a faint star located immediately off its northern end. Looks like a nice high surface brightness PN, just asking for more mag but ofcourse the seeing realistically didn't allow anything beyond 200x.

At this point I went inside to warm up, and ended up dozing off for over an hour. Well, that was actually good coz when I woke up Jupiter was well positioned for viewing.

[Sam]

Nice report SAB - plenty of detail in there, almost like being there! You've had a great couple of nights by the sound of it.

[Paxo]

Nice report SAB, lots of clusters in there I see, my favourite subject. There's nothing like southern skies for those naked eye open and globular clusters.

Steve..

[centroid]

An interesting report, and having been in Oz (WA) twice last year, I can now somewhat relate to the sky down there.

Dave