Omega Centauri

[dennisjames1]

Hi Everyone

In fairly light polluted skies my 80 mm doesn't resolve stars in the cluster visually, what would do the job ?

cheers

Dennis

[omegacrux]

I find a lower ep anything over 20-30 works a lot better in my ed80 than a higher power
I like the view with a 2in 30mm , unless I'm using my big dob , then you can use a lot higher power
Also the light gathering of an 80 isn't that great
Try Tucana 47 that has a lot brighter core

David

[Doogs38]

Hi Dennis. My 5 inch newt just starts to resolve individual stars with direct vision. My 14 inch dob shows the cluster as a wonderful spectacle of stars all the way to the core. Alex.

[madbadgalaxyman]

Sometimes, moving to a much higher power works, and increases the visibility of the stars in a cluster;
at least, if your scope is good enough to take that extra magnification!

Accurate focus is critical to achieving the resolution of a globular cluster (so perhaps focus on a brighter star nearby, instead of focussing on the cluster) and very good optical quality can also aid in seeing the stars within globulars with small apertures.

Also, a really good quality eyepiece can give you "the edge" when it comes to trying to resolve globular clusters.

Also, if you don't succeed, try and try again; experienced deep sky observers like our Dana and Paddy will spend enormous amounts of time, sometimes on several nights, trying to tease out the details in a single object!

I have definitely resolved Omega Cen with four inches of aperture in good dark skies. (A four inch has 78 percent more light gathering power than a three inch.).

Omega Cen is at 5.2 kiloparsecs from our Solar System according to William Harris globular cluster catalog
(this is equivalent to 17,000 light years)

NGC 6752 in Pavo is substantially closer than Omega Cen, at a distance of 4.0 kiloparsecs (= 13,000 light years), so the brightest stars in it are somewhat brighter than the brightest stars in Omega Cen; so I have succeeded in partly resolving NGC 6752 with a three inch refractor.

Another globular which is particularly easy to resolve is Messier 22.

[mental4astro]

Omega Centauri I've resolved in 11X70 binos! Very tight, and experience was the only way to do so, and a dark site helped.

But, I've also resolved it in my 80mm refractor from home in Sydney. Like Robert said, juicing up the magnification is the key here for light polluted skies.

Another tip is to be patient - the constituent stars are faint, & require careful averted vision. Up the magnification to about 80X to 100X and look to on side of it & fix your attention there for a moment. This will saturate your eyes & the resolved stars will suddenly just lift out. This is a little trick that helps with all GCs, of cause depending if your aperture can resolve the GC in question. An 80mm scope will also resolve 47Tuc.

[dennisjames1]

Thanks everyone

I have a 6inch LX80 Meade SCT which i bought as well. just for a little more aperture.

So i will give it a try, i gather that it should start to resolve some of those stars.

I do like the convenience of that little grab and go ED 80 mm though;)

Thanks again

Dennis

[astro744]

I just looked at Omega Centauri with a Tele Vue-60 and the following eyepieces under mild light pollution:

24mm Panoptic - 15x Outer part resolved. Inner core needs more magnification.

19mm Panoptic - 19x Same as above just a little easier.

16mm T5 Nagler - 22x Core begins to scintillate with stars. Effectively resolved.

12mm Radian - 30x Core clearly resolved.

6-3mm Nagler Zoom at 6mm setting - 60x Core easily resolved.

15 x 70 Celestron binoculars (hand held) - I shake too much! (Although I did see outer part resolved briefly)

[dennisjames1]

Nice love Televue product beautiful gear :)

[speach]

It's a naked eye object in my back garden. Albeit you have to know where to look, and use averted vision.

[brian nordstrom]

:), Here goes,

Takahashi sky90 f5.5 , 5mm TV Radian 100x .
From Wolf creek Crater, super dark and transparent skies Omega resolved almost to the core , an easy naked eye object.
From home only hinted at , partial resolution .

Istar 127mm f8 doublet achromat , 10mm TV Radian 100x.
From our Dark sky site beautifully fully resolved , the way only a quality refractor can .
From home , partially resolved but still nice , not as contrasty .

Celestron C9.25 f10 , 24mm TV Panoptic 97x.
From a dark site , simply spectular !!, totally resolved to the core , 'Owl's eyes' easily seen ,very very nice.
From home easily resolved to the core , just not a contrasty again and the 'Owls eyes' not seen .

So there it is , I believe that dark and steady skies are the key here and if my sky90 from an exceptional site like 'Wolf creek' or our dark sky site at Brookton WA can resolve it under the same conditions your 80mm just might ;) , good luck and please report back your results.

Brian.

[cometcatcher]

For me, I get the greatest pleasure from globulars with the greatest aperture I can get hold of, even the brightest globs like Omega Cent and 47 Tuc. Sure it resolves some in smaller scopes, but aperture rules on these objects. Through the 16" it's awesome. I would like to see it with a 20" to 30" one day!

[dennisjames1]

I've added a lx200 ACF 8 inch now, so on the ioptron mini tower 2 the 80mm triplet on one side and the LX 200 OTA on the other. be interesting to compare.

[brian nordstrom]

:) Look forward to the review .
Brian.

[Fox]

Hi Dennis, I think your 80mm should be able to resolve it. It sounds as though you need darker skies, and pump up the power. Your 6 inch is a no brainer, it should readily resolve, again best with dark skies and enough magnification. My 4 inch Genesis easily resolves both Omega and 47Tuc - from dark skies, the pictures are glorious, I look at them for hours and hours. They are balls of fine grade sand, its mind boggling that each 'particle' is a sun, hoarded together…

Tell us how 80mm, vs 6 inch, vs 8 inch goes!

PS: I used to have an 8 inch Meade SCT, and it could do things my refractors can't. On the other hand, its amazing how the refractors can strut their stuff in other ways, esp from dark sites. Also, I owned the 8 inch SCT over 30 years ago, and sky conditions were SO different back then. I can totally recall how dark the Melbourne South East suburb skies were compared to the white wash of nowadays. It's rather heart breaking for us observers - that's another story, eh?

Fox

[Rob_K]

Might be. In lighter skies Omega Centauri is a big washy nebulous patch in my 4.5" but in dark skies it's like sparkling cotton wool.

Cheers -