Some Herschel Observations
Posted 20 August 2009 - 01:11 AM
I find that Mr. O'Meara's book is helpful in providing directions for where to find the various objects, but to really nail some of these I am using my Sky Atlas 2000 to follow his directions as the maps in the book just don't work for me.
So here are some objects from the other night. School started so instead of being able to observe whenever I want/can, I have to be selective. Go figure though, last night and tonight were absolutely wonderful in terms of seeing. Hopefully it lasts until Friday when I can go out again.
NGC 6638 (originally I put 6438)
This is a globular cluster that shows up, but as a very faint fuzzy.
NGC 6440 a Globular and NGC 6445 Planetary Nebula Box or Little Gem
I have already observed the planetary and recently but decided while looking at the globular and seeing both objects fit in the FOV to include both in the sketch. NGC 6440's core seemed visible with averted vision so I included it.
NGC 6781 Planetary Nebula
This object was very large and I could detect it without the Ultrablock filter but the filter really made it stand out. I also detected that the SW area of this PN was somewhat brighter than the rest of the PN. Overall, not a lot of detail was to be seen.
That's enough. I'll have to say in doing the Herschel's that I do about 7 to 8 in an evening and then I spend my time on a page of an atlas looking or working double stars or the best of the Urban. Some of the Herschels don't leave a lot of detail. Fun to find them though.
Posted 20 August 2009 - 03:04 AM
i had a similar view of ngc 6781 this week, have you tried planetary nebula ngc 6891 in Delphinus yet? iirc it had a very starlike core, (or a central star) a nice neb too!
Posted 20 August 2009 - 04:28 AM
Posted 20 August 2009 - 02:18 PM
Excellent observations of two interesting globular clusters and a planetary nebula. It is fun hunting down these elusive targets. Thank you for sharing them with us all.
Posted 20 August 2009 - 06:11 PM
These are fine sketches of your targets. Most of the fun is in the hunt and trying to record them as the eye and brain sees them. Very well done.
Posted 21 August 2009 - 01:27 AM
Kris, I agree with you on NGC 6891 and its star like core.
Jim, I agree that 6 to 8 is ambitious and the reality is that some nights its just not doable (until I am off for a 3 week period which happens 4x a year). Some nights I only get two or three down and I just can't pull a couple out even though I know I'm in the right area (backyard vs dark site). It also depends on whether many of them sit together and can be gone after close together. I'm not far into O'Meara's book so we'll see if I can keep combining items in the same area.
Carlos and Frank, thanks for your input and I totally agree with you, I love being able to hunt these down and record my observation. A question I have if anyone here knows is how many of the Herschel 400 do you think have the ability to be sketched? Sketching can cut me down from 6 or so a night to 3 or 4 a night or less. I'm in no rush to finish the Herschel 400, and am enjoying working on them, but just wondering how many realistically can be sketched?
Roland, thank you, I've sent you a PM.
Posted 21 August 2009 - 08:04 AM
Frank, you are correct it should be NGC 6638. Correction made and tonight I'll correct the sketch and repost that. Thanks to both of you.
Posted 21 August 2009 - 10:40 AM
Posted 22 August 2009 - 12:41 PM
Good list of targets too; I only have the last of them logged. You captured most of the detail I saw in it in your sketch (save the central star, which was pretty fleeting even with more aperture):
NGC6781 III-743 10/17/2007 21:30 UT; Pickering 7, NELM 5.5, SQM 20.5
16" SCT @ 260X, UHC
Good size planetary but with fairly low surface brightness. Circular shape with slight brightening to S and marked fading to N. Slight minima to center, more pronounced at 375x (12T4) or with UHC at 260x.
Fleeting hints of several foreground stars, but nothing confirmed at 510x. Ghost of a central star, perhaps visible 5% of the time in averted, offset slightly to E of center.
Posted 22 August 2009 - 07:07 PM
Jeff, yes, I've moved to digital but sketch still at the scope. On my blog I plan to post the sketch, the digital and the DSS version for comparison but feel that is too much here. It's also because I won't be able to get the software or scanner I really want until next spring due to some financial things that have come up at home and I just don't like how my current scanner scans (not just sketches but other items). That and I have enjoyed getting use to using GIMP so that has been helpful.
I was out last night from 9:40p.m. until 4:00a.m. at a dark site and bagged 7 Herschels and a few other items. Some Herschels I just don't sketch cause there isn't much there. I did sketch five items last night and they included NGC 6905 in Delphinus (fantastic one, I saw lots of detail on that and O'Meara's star hop is easy, yet fun); NGC 6629 a PN in Sagitarius; NGC 6568 OC in Sagittarius; NGC 6645 OC in Sagittarus; NGC 6664 OC in Scutum; NGC 6818 PN in Sagittarus and NGC 6712 GC in Scutum. Not a bad night. I'll post a few I hope tomorrow here.
Stephen O'Meara's Herschel guide is strong on directions, though I've modified some as I follow his hop and his detail maps are helpful, but the general maps are not. My Sky Atlas 2000 is a better choice there and often I find other ways to approach an object.
I have other comments on O'Meara's book so far but I won't go into them here, I'll put them on my blog.
Posted 23 August 2009 - 04:31 AM
I took a quick look through your blog -- goodness, your productivity puts some of the rest of us to shame! 14 Messier sketches to go? I've only gotten 22 of them done, and I think I've been sketching for more than twice as long.
By the way, that's a fantastic moon over the mountains sketch on your blog.
Let us know when you put up some voice recorder files; I'm quite curious. (I tried one for a little while myself, but couldn't really get used to it.)