Hi All,
Quote:
Originally Posted by Rob_K
Although I had to wait till the end to read the best!  Nice score with AM-4, in fact all of the difficult globulars for that matter! I'd imagine if you could see Pal 5, then Pal 6 would be a (relative) doddle. You seem to have missed UKS 1 though...   |
Yes Rob, AM-4 was a bit of a surprise actually -- I didn't think that I'd see it as it is incredibly faint (one of the intrinsically faintest GC's and was until very recently considered the most remote Milky Way GC. I only had a go on a whim.
Being at Zenith was a mixed blessing. Straight up is the best view but is 2 1/2 steps up the ladder and a bit of a lean in to the eyepiece -- uncomfortable.
Being so close to zenith means the accuracy on the Argo isn't so good - even with 8,000-step encoders (its not the fault of the Argo, its just that the azimuth lines are converging so closely) if your pointing is out just a fraction (say a couple of tics) you can be 2 medium-power field's out. The solution with the Servocat is to do a go-to to a reasonably nearby bright and certain object and then do a "Local sync" on that object -- which will land you right on it.
After I'd done this (I used IC 4351 which is an unmistakable eg 2 degrees away) I still seemed to have a lot of trouble properly identifying the star-pattern shown on Megastar/DSS at the AM-4 field. I did about 3 or 4 trips back to the PC to try and make he pattern certain. With an object this faint, you have to know
exactly where to look, to within an arc-minute in the field, or you'll never find it. While this was going on, several times I seemed to be seeing this very faint 16th mag galaxy near what I took to be the right spot (from the pattern) which was a severe distraction because I knew there was no galaxy that bright within about 8 arc-mins of AM-4. That is when it dawned on me -- the "galaxy" I kept seeing occasionally was in fact AM-4. It is extremely faint and low SB. I switched up to the 9mm T1 Nager and then I was seeing frequent intermittent views of it. I called my mate Gary over and within 30 seconds he'd confirmed it as per the DSS overlay on Megastar.
I was pretty (very actually) happy with that. I'd thought AM 4 was beyond 46cm, so there you go. The conditions could hardly have been better. The SQM reading was 21.82 at that time, the seeing okay to good and it was straight up.
Re Pal 5, There are quite a few observers out there who rate Pal 5 as not very hard. I respectfully disagree -- I think it is a very, very tough object for say a 10" and not easy for even 18". Once you've seen it once for certain, it's easier next time though. Pal 6 is a difficult object too but it seemed okay on the night -- not difficult at all.
With Pal 5. again, one of the problems is discarding a paradigm. Don't look for anything that actualy looks like a GC -- instead look for a mod-sized weakly milky patch with a slight over-abundance of faint stars (mag 15.5 -16.5) within it. That's what Pal 5 looks like even in 18-20" 'scopes. I forgot to include it but I also took a look at AL-3 -- one of our Milky Way's "newest G.C's and DJ 2 too.
UKS 1?? Ummm ... that's absolutely beyond the pale I think. Even Barbara Wilson needed a 1m 'scope to see it.
Quote:
Originally Posted by seeker372011
after one all nighter I flag..needless to say you seasoned observers don't..something in what you eat ???
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Nothing like that -- when I'm up at Mudgee, it's the knowledge that you don't have to get up at any set time in the morning that allows you to go until you are dropping off your feet. Sleep in as long as you like -- even 11am or 12md makes it even easier to go later the next night. If you feel like it -- take a "nanna-nap" in the arvo too.
Quote:
Originally Posted by Jone5y
I grew up in Mudgee and try to get back there when possible for some dark, clear skies. Where were these obs performed?
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Steve, it is at Observatory Downs here:
http://www.mudgeeobservatory.com.au/locate.html
Technically it's Gratti, but if I wrote that, almost no one would know where it is was.
Thanks for the comments guys!
Best,
Les D