Log in

View Full Version here: : Hourglass Nebula


§AB
15-10-2007, 07:51 AM
Decided to go outside for a short session last night. Well, it was clear and calm - looked perfect to catch Jupiter before it disappears behind my roof forever.....or so I thought.

Telescope: 10" Newtonian
Seeing: 2/10
Transparency: 3/5
Lim Mag: 3.5-4 (where sagittarius was), 4.5 (zenith).

Dropped in the 9mm plossl for 138x and it didn't take long to be dissapointed. Melbourne has turned on its normal seeing yet again. After a while however, I got a few good glimpses at 166x, even hinting at a few festoons. Well clearly tonight won't be a planetary night.

Decided that I'll do some DSO observing in Sagittarius, I had to go inside and grab more eyepieces. Did that and had to re dark adapt. Then I realised I forgot my nebula filter. Oh well, I wasn't going to loose my hard earned dark adaption to retrieve it.

I decided I'll try to find the Hourglass Nebula in M8. Easy to find, just look for the brightest portion in M8. At 227x, I could just hint at the hourglass. Although the seeing was shocking which is normal in Melbourne's climate, I needed more magnification to see it. At 416x, the seeing made a mess of everything. Generally, tonight would be a < 200x night. Anyway, at 333x I got my best view of the object. Using averted vision, I could see the shape, like two triangles joined at their pointy ends. Surrounding the nebula was a circular haze. I could also see a darker area adjacent the western edge of the Hourglass figure. Well, I was impressed considering the light pollution across the western half of the sky.

I also took a look at M22. At 166x I was almost convinced I was looking at an open cluster. Interesting. It was resolved, but didn't appear condensed. Using 333x, I basically got a larger version of what I was seeing at 166x. The stars seemed to spread across a background haze with dark lanes running across it. Maybe I was observing something else, but I was where M22 was supposed to be.

The Trifid Nebula wasbarely visible. At 138x, I could just barely make out the nebula and dark lanes. It was sitting in the light polluted west so I wasn't surprised.

The Planetary Nebula NGC 6818 was a nice, greenish circular orb, not unlike Uranus. At 333x, I the central region appeared slightly dimmer than the outer areas. Because of the seeing, tonight was not ideal to observe PNs.

I also checked out the globular M69. At 69x, it appeared as a fuzzy ball. Using 227x, the outermost stars started to show resolution and became noticibly more granular in appearance. I didn't use higher mags as the seeing basically made a mess of anything above 200x.

h0ughy
15-10-2007, 10:04 AM
nice report. I have seen 6818 through a 18" one night that was a buzz

Rob_K
15-10-2007, 11:18 AM
Another top report §AB! :thumbsup: Interesting your description of M22. As one of the brightest globs in the sky, it never disappoints - so it doesn't quite tally, but who knows what the atmospherics were doing to the view! At Silverton it was magnificent in the dark skies, and I saw it through a number of scopes. Kept getting drawn back to it :lol:!

Good to hear some PN descriptions - keep them coming! :thumbsup:

Cheers -

§AB
15-10-2007, 12:36 PM
I thought it was quite odd. It was only a short session so I had very basic star charts on me. I'll check in the Millenium Star Atlas if there's anything near M22 that I may have saw instead.

Dave47tuc
15-10-2007, 12:59 PM
Sab,
Near M22 is M28 Also NGC 6642 and NGC 6638. So you may have been on one of them. But the two NGC Globulars are faint. So my guess is that you have mistaken M28 for M22.

keep up the great observing you do:thumbsup:

Regards,
:)

DougAdams
15-10-2007, 02:19 PM
Good stuff. You threw me with the hourglass nebula - I thought that was a planetary. M22 is big, bright and obvious, but there are a ton of globs around there and easy to get lost.