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Old 22-07-2012, 09:45 PM
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shelltree (Shelley)
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Observation Report 20.7.12

Observation Report 20.7.12



After a depressing week of no observing and lots of rain , I was itching to get Berenice out under the stars and try for some new goodies.

My first target was NGC3918. The Gumball Nebula (as my friend and I so fondly dubbed it ) has eluded me ever since I first set up Berenice. Even when I saw it for the first time, it was because of my friend's amazing effort and determination. So I was really hoping to find it all by myself. But alas, yet again it eluded me and it wasn't long before it was behind the trees and out of sight.

The next target on my list was NGC5102. I had looked for this galaxy my last time observing and had come up empty. On my star maps, it seemed like the galaxy was almost on top of iota centauri but after checking it out in Stellarium, I realised it wasn't as close as I had first assumed. I made sure I placed iota centauri at the edge of the eyepiece and there it was! So very, very faint, I am really surprised I even found it. An average sized star, no bigger or brighter than the rest yet with the slightest of fuzzy smudges through the middle, I knew I had found it. I was very happy that after the frustration of trying to track it down last time, that I had finally found it!

I had another look at Centaurus A, mainly to make sure I could still star hop to it easily and not get muddled up. Sure enough I jumped from mu centauri and easily found Centaurus A. I think I'm starting to get a basic grasp on star hopping just by studying the maps and using my binos as an aid! I really wanted to find M104 again but alas, by the time I got home from work, had a bite to eat and a shower then set up, it had already disappeared behind the trees.

I decided I wanted to find something new and seeing as there was some pesky cloud floating around Scorpius' stinger for awhile that made trying to find The Bug Nebula frustrating (not to mention it was almost at zenith by this stage and a bit of a strange on the legs and back) , I shifted the scope to a different position in the yard so that the stars between Menkent and iota centauri were visible. I had been checking out Star Maps Pro, which has a very handy section called "Tonight" which tells you all the exciting things in the sky for the night and their rise time, transit time and set time. I decided upon M83 and so had to move the scope!

I used my binoculars first. In between Menkent (theta cen) and iota centauri, there was a small cluster of bright stars that formed an upside down 'Y' shape. I knew once I found the 'Y' of stars that if I continued downward following a squiggly line of close together stars that I would then reach two brighter stars. The fainter of the two stars would lead me straight to M83, which lay directly below it. In the binoculars, there was a definite faint fuzzy patch so I lined up the stars in the finderscope and sure enough, there it was!

I was actually really surprised by how faint it was, considering how big it looked in my binoculars. It had a bright nucleus with the fuzzy edges but it wasn't really popping out at me. I think the seeing was to blame, there was still cloud scudding around, it had cleared by the time I focused on M83 but I think there was still some invisible wisps around that made it hard to pinpoint any detail.

Seeing as I had moved my scope, I now had a good view of Aquila and Scutum. The glare from Brisbane and probably from Archerfield Airway as well, was pretty severe so I could only make out the brightest of stars. After looking at Star Map Pro again, I decided I wanted to find the Wild Duck Cluster. I had heard of it before, even tried for it with binoculars but I don't think I knew exactly what I was looking for or where to look for it. After studying the shape of Aquila against Star Map Pro, I knew where I needed to point. I hopped my way upward and noticed a bright fuzzy in the finderscope.

When I looked in the eyepiece, WOW! It was so bright and so dense, shimmering and sparkling! The first word that came to mind was "crunchy". The stars in objects like M6 and Omega Centauri, seem delicate, fragile and twinkle like glitter against deep velvet. But this was something different. The stars twinkled and shone like jewels, cut precisely and their edges giving a 3D effect. I was really blown away. What a beauty!

The last object for the night was the Eagle Nebula. Which, I actually happened to stumble upon by chance! I was looking for clusters in Scutum and noticed two clusters close together and centred one in the eyepiece for a closer look. I was blown away again! The dust was so wispy, so bright, like tendrils of milky smoke against a back drop of dark dust and stars, it was a sight to behold! I decided to try to find it for a second time, to make sure I was in the right area and I was. It is so bright, it is hard to miss!

I did try for a couple of other objects but the seeing was pretty rubbish by this point. The sky glare was ridiculous and turning to face more South wasn't proving fruitful either. So I called it a night after a couple of hours and headed to bed. Alas, the cold breeze that night (which I actually found wonderful and refreshing) coupled with my bad shoulder saw me wake up with a whopper of a migraine the next morning and the sniffles and a sore throat. Not to mention I woke up with an agonising stomach ache at about 1am.

Now that I'm feeling a bit better, I can most definitely say it was worth it! (although I stayed in tonight, just to be sure )
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Old 23-07-2012, 01:27 AM
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Suzy
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Great report as usual Shell!

I forgot about the Wild Duck Cluster- I haven't seen it before and after your enthusiasm I can't wait to see it, it sounds fabulous. Must add the Eagle Nebula to my list too- I saw it at Ron's last month through his scope but I haven't tackled it myself. I thought it would be dim object from suburbia so you've excited me on seeing this one too!

I think you're a legend for finding M83 as quickly as you did- aye, I had sooo much trouble finding it. It wasn't until I came across the star hop from Centaurus (the one you used), that I was able to find it. Also, I was expecting something magnificent as said in all my books. Alas, all I got was a bright stellar core and that was it. I've gone back to it several times and still nothing. Others have noted too that from light pollution, it's a poor display. When I looked thru Ron's 16" scope last month, I had a look at it and it became quite obvious why I couldn't see anything. I did see the full disc, but to me it looked fairly faint- well faint enough to understand why it didn't show up from my house. So since then, I've looked and studied hard again from my place and I did see an extremely faint area (not a defined disc) surrounding the core. But in all honesty it would not have been apparent had I not known what to expect. I had to look really hard!

Here's a star hop for The Blue Planetary (NGC 3918). It's a popular star hop that I've used as well.
http://www.ojb.co.nz/owen/XuAstroObjects/NGC3918.html

Sorry to hear that you weren't well afterwards. I wonder if it was hayfever? I often seem to suffer (spring & autumn) the next morning after observing. And the strange this is that this week (and it's winter so I don't get it!) I've had a touch of hayfever. Must be all that wind.

Keep the reports coming Shell, you and Berenice are sure having a blast together.

P.S.
What eyepieces did you use on those objects? Would you mind specifying them next time please. Just so we can reflect the report on your magnification.
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Old 24-07-2012, 12:22 PM
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Paddy (Patrick)
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Thanks for another great read Shelley. Being a face-on spiral, M83 will suffer badly with light pollution. With a dark sky and plenty of revisits and used of averted vision you will be amazed at how much detail you can make out with a 10-12" scope. Messier 11 is a stunner - loved your description. The other nebula near the Eagle would have been the Swan or Omega Nebula, M17. It is well worth a visit next time you're in that neighbourhood. One of the best emission nebulae in the sky IMHO.

Keep these great reports coming!
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Old 29-07-2012, 09:30 AM
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MattT (Matthew)
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Great report Shelly glad theres observing to be had somewhere....so many stars covered by so many clouds down here, bino's are an observers best friend I agree, as well as Sky Safari, keep em coming.
Matt
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Old 14-08-2012, 07:00 PM
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madbadgalaxyman (Robert)
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Quote:
Originally Posted by shelltree View Post
Observation Report 20.7.12
The next target on my list was NGC5102. I had looked for this galaxy my last time observing and had come up empty. On my star maps, it seemed like the galaxy was almost on top of iota centauri but after checking it out in Stellarium, I realised it wasn't as close as I had first assumed. I made sure I placed iota centauri at the edge of the eyepiece and there it was! So very, very faint, I am really surprised I even found it. An average sized star, no bigger or brighter than the rest yet with the slightest of fuzzy smudges through the middle, I knew I had found it.

)
NGC 5102 and NGC 5253 are two Dwarf S0 (pronounced "Ess-Zero") galaxies in the nearby Centaurus Group of Galaxies that includes NGC 4945, NGC 5128, & M83.

The innermost portions of NGC 5253 and NGC 5102 are of reasonable surface brightness, but over the years I have found that it takes a really excellent (dark and transparent) sky to see them as more extended objects.

Both objects contain a "spheroidal" component (a bulge) together with a flattened "disk" component, which makes them nominally galaxies of Hubble Type S0, in that S0 galaxies are disk+bulge systems having overwhelmingly old stellar populations.

What you may be seeing is just a small central part of the overall galaxy, in the case of NGC5102.

In the telescope, under perfect conditions, NGC5102 resembles a bright spheroid, together with a surrounding "envelope" with a lens-like outline.

The very extended envelope is what really makes this galaxy look like a galaxy, but it is totally invisible in conditions that are not perfect. (it is overwhelmed by too much sky brightness ; also there is not enough transparency to give a good signal to the eye from this vanishingly faint diffuse light that is composed of innumerable star images!).

Take another look at this galaxy in really excellent dark-sky conditions; you will be surprised how big it really is.

This said, both of the dwarf S0 galaxies in the Centaurus group have been thought to be unusual;
NGC 5102 has relatively blue colours (for an S0 galaxy) due to a recently ended ( though modest) episode of star formation, and NGC 5253 has a bright and compact centre of irregular appearance...... which is a bona fide ongoing (or very recent) burst of star formation!
[[ There has recently been an ongoing paradigm shift in humankind's knowledge of S0 galaxies; giant S0 galaxies are disk+bulge systems with overwhelmingly old stellar populations, as has been known for a long time, but it was recently discovered that dwarf S0 galaxies often do have some ongoing star formation ]

NGC 5102 looks "faint", but it ain't really! Think of this object as being comparable in brightness to a 9.6 magnitude star......except that the light of this galaxy is spread over a vast area of sky; the major (long) axis diameter of the diffuse envelope is probably some 9-10 arcminutes!!!

Last edited by madbadgalaxyman; 14-08-2012 at 07:50 PM.
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Old 15-08-2012, 03:05 PM
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madbadgalaxyman (Robert)
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Oh, and one more question, Shelley,
what magnification did you use on NGC 5102?

Low magnifications are sometimes necessary for objects of very low surface brightness, in that the slightest extra magnification can make the object "disappear" by moving it to a surface brightness that the eye cannot detect. This object might actually look better in 50-100 mm binoculars than in the telescope, because of the additional contrast provided by two eyes linked to a human brain.
(for example, I have found the spiral arms of M33 to be more obvious in large binos than in the telescope)
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