I was wondering if anyone would be interested in a regular thread for a series of challenging objects for a variety of size scopes every month.
to start
Binoculars
Nebula in another galaxy: 10x50 Bino's will show the Nebula NGC346 in the SMC. Look for a small glow just a little North East of the centre of the galaxy. Once you have seen it remember that you are looking at a Stellar nursery about 200,000 light years distant.
4-6" Scope
This observation is really for a rich field instrument f5-6. The Sculptor Dwarf is a satalite galaxy of the Milky Way. It is a Dwarf Spheroidal with a very low surface brightness. Select a low power wide field eyepiece and position the galaxy in the middle of the field. If you can see a brightening in the sky background you have found the galaxy. if your not sure give the scope a shake if the glow mooves you have it.
8-10" scope
NGC6288 is a galaxy in Sagittarius and another satalite of the Milky Way. It is an Irregular galaxy which contains numerous HII regions. It was the first galaxy to have the Variable stars correctly maesured and as such was the first known extragalatic object. In the 8-10" scope it wlill appear as a low surface brightness bar about 16' long and 6' wide. If you have a UHC filter handy have a look again and see if you can see the HII regions on the Northern end of the galaxy.
12-14" scope
WLM is another local group galaxy. It lies about 2.5 million LY away. This is a difficult galaxy to observe looking very similar to NGC6288 only smaller and fainter. Where NGC6288 has a gradual drop in surface brightness WLM has quite a sharp drop, making it easy to distinguish from the sky background.
It is 7' long by 4 ' wide and has a fairly bright star superimposed in the centre of the galaxy.
16-18" scope
WLM is good for this size scope as you should be able to catch an extragalatic globular. See the image attached to this message and you will see thew cluster marked. This is one of the easiest Extragalctic globulars.
20" and bigger.
You thought I would go for another Local group member and you are correct. This will be another challenge and it comes in 3 parts.
First part the Fornax Dwarf. not a particularly hard challenge for the size instrument requested. Second the 5 globulars again marked on the image posted with the message. Last is the Cluster marked as C and this is the real challenge. The only open cluster in the Fornax galaxy.
Anyone with a large instrument can try all objects and I urge anyone with a smaller scope to try and look at the objects listed for larger instruments. you never know.
I hope that people like this and if you do I will try and have one ready for each month. Till December......
Andrew
Myself, Mike and Andrew Durick used to compile a monthly observing challenge list a couple of years ago. Whilst none of the objects were difficult targets we would select one object of each type each month as the observing challenge. While the concept was great, it was very time consuming for the small amount of interest that was generated.
I hope you can arouse enough interest to make it worth your time and effort. Here are some links to the older files that we prepared a couple of years ago.
Might have a crack at Cluster "C" in the Fornax Dwarf when I'm up at Mudgee for several nights later this month, though it looks an exceedingly tough object for 18". There will be a very, very good 20" up there too so ...
Have seen the G.C's in the Fornax Dwarf with 12 and 18". It has always struck me as a little odd that such a small dwarf spheroidal has so many G.C's. The SMC -- a much more massive eg has only one "real" G.C (NGC 121) by comparison. Fornax probably hasn't undergone much in the way of gravitational interactions with major galaxies but I wonder why so many for such a small eg? Must be either something in the dynamical history or perhaps dark matter that has influenced this ??
The G.C in the WLM (one and one only here ... again) is also a suprisingly easy object in an 18" given the distance. Once you know exactly where to look -- piece of cake.
I am glade that this has meet with aproval from everyone. I will try and supply some additional details in the next few days. While I listed the Fornax dwarf for the largest scope please try with smaller instruments, a large pair of binos 15x80 and up will show the galaxy or a good 4" scope with about a 1 degree field of view. An 8" scope should see the brightest of the 5 globulars and i will let you discover which one that is. A good 12 should show 4 of the 5 globulars. Good hunting.
Andrew
The WLM galaxy (MCG -03-01-015) is at the bottom of this SkyMapPro map for midnight DST tonight.
The bright star between NGCs 210 and 247 is beta Cet or Difda (the second frog). http://penelope.uchicago.edu/Thayer/...TA/Cetus*.html
found ngc 346 tonight, very faint glow in the 7x50's 47tuc was good also. moved down to lmc & pretty sure i saw another GC below it, but i cannot identify it from my star maps - anyone know what i might have seen
thanks daniel
will try & tick off sculptor dwarf on weekend if weather holds
found ngc 346 tonight, very faint glow in the 7x50's 47tuc was good also. moved down to lmc & pretty sure i saw another GC below it, but i cannot identify it from my star maps - anyone know what i might have seen
Any chance that it was the Tarantula nebula (NGC 2070) which looks a bit like a GC in binos.
Saw the WLM galaxy after the moon set tonight. It was very faint in the 12". I had to wait till 30 mins after the moon set before I saw it, and it was better with low power (21mm EP, 71X).
Great work there Daniel, The SMC looks great in Binos as you get to see the whole galaxy in one go. Its great to hear from people going out to look at these objects. Next month I will base all the challenges on the SMC. and it's surrounds.
Good work with WLM Glen. It is quite faint in a 12" scope. Did you try for the Globular? Andrew
I took advantage of unexpectedly clear skies to try for some of the targets. All with 12' Newt, so I cheated a bit on the targets for smaller scopes.
Sagittarius was too low on the horizon so I gave NGC6288 a miss, but had found it previously after one of Rob K's observation reports. Sculptor was high so I went for the dwarf which I'd previously sought in vain. An I found it - very happy. Low surface brightness is quite an understatement! Went on to find WLM - will visit again for further inspection. By then I was on a roll with local group dwarf galaxies and decided to go for the Fornax dwarf and I don't know if I'm kidding myself, but I reckon I could make out at least a couple of the globulars.
I then went on to browse the various galaxies of Fornax an Eridanus.
In short, a wonderful night's viewing. Many thanks Andrew for the challenge which inspired me to look for things that I would normally pass up as too hard or not interesting enough. Quite nice to get to know the Local Group a little better as well.
Thanks for the link Glen - think the distance needs to be corrected though (over 3 million ly).
