Omega Centauri vs 47 Tucanae

[m11]

Hi All,

My understanding is that Omega Centauri GC is larger and brighter than 47 Tucanae GC. When comparing both from dark site and urban skies seems to show 47 Tucanae as coming out as brighter.
Not sure if its just my perception or my telescope .:question:

Does anyone have a similiar view?

Mel

[Atmos]

I am going to guess that it is likely due to where they are in the skies at the moment. This time of the year Omega Centauri is likely to be lower to the horizon than 47 Tuc and that will make it appear dimmer, looking through more atmosphere, potentially more light pollution as well depending on where you are.

[m11]

Hi Colin,

Thanks for replying. Will need view at later in the night or wait later in the year.
So I assume you see defintely see Omega Centuri as brighter?

Thanks,

Mel

[Atmos]

To be honest I have never really noticed, there is only about 0.3 mag brightness between them, Omega Centauri being bigger and brighter.

[m11]

No problems, thanks for replying.

Just noticed that many people who have viewed with me say the same thing, that 47 Tucanae is brighter.

Will wait until Omega Centauri is higher as you suggest and view again.

Thanks,

Mel

[barx1963]

Overall, Omega Centauri is brighter. The U2000 field guide lists its visual magnitude as 3.9 while 47 Tucanae is listed at 4.Ihave read elsewhere of larger differences.
The key thing is that 47 Tucanae is far more compressed so appears much brighter. In a decent sized scope, 47 is much more interesting viewing as Omega is just so spread out.

Cheers

Malcolm

[bigjoe]

Hi Mel.

I find I need to wait for Omega to rise higher in the sky compared to TUC 47, otherwise it can be quite unimpressive in comparison.

The core of TUC 47 always seems to be much more intense; just loverly.


bigjoe

[m11]

Hi Malcolm,

Thank you for the explanation. It makes alot sense. 47 Tucanae has always been my favourite GC
Both are lovely GC and we are lucky to have both.:thumbsup:

Mel

[m11]

Hi Bigjoe,

I just need to wait a bit later to view it seems. It just seemed to me alot dimmer and I have been wondering why when i compare both.

I love the intense core of 47 everytime, it blows me and everyone I show away.
Thanks again for responding and giving a logical explanation :)

Everyone has been really helpful :)

Mel

[pdalek]

The surface brightness of the core of 47 Tuc is higher than that for Omega Cen. However it drops faster with radius.
From high LP sites the high core brightness makes 47 Tuc stand out. From dark sites the greater size of Omega Cen dominates.

A good paper comparing the two
http://arxiv.org/pdf/1305.6025v1.pdf

[m11]

Hi Pdalek,

Thanks for the link on GC and explaining the differences between both GC.Will need to spend time reading it and hopefully understanding it.

Appreciate everyone being so helpful :)

Mel

[uwahl]

I observed Omega Centauri at 400x with a 10 inch scope at a dark sky site with 20% humidity and a very steady atmosphere in western Queensland last year. The core stars were rock steady. Now that was impressive.

I have never before or since been able to do that but as I have only been observing for two years I live in hope.:D

[m11]

Hi Uwahl,

Agree with you , its those moments you always remember and hope to replicate again.

:)

Mel

[The_bluester]

Yeah those exceptional observing moments are memorable aren't they. One of my best nights was at an ASV Messier star party and for about half an hour (I think, felt like all night and also like ten seconds, all at the same time) I had awe inspiring views of Saturn at around 430X. Never before and never since. I was just transfixed until the seeing deteriorated again.

On the glob topic, I have always found 47 Tuc my personal favourite, probably for the reasons described above it just seems to carry more WOW factor for me. It is a bit like that first glimpse of the Orion nebula for the season, an old friend, but for 47Tuc it is like that every night.

We have an astro night planned at home for this Saturday and I can safely assume the scope is going to spend quite some time aimed at 47 Tuc, despite the fact it will be less than ideally placed.

[bigjoe]

Yes 47 Tucanae; straight up near the zenith one night in winter at my house in Concord, Sydney in a 7" Mak , the view was as memorable as the view in a 10" SCT at my property at Castelreagh near Penrith!

You just never forget those moments!


bigjoe.

[MattT]

Both best observed with Binoviewers IMO...both give the 3D effect. Have spent hours with 30mm plossls a 1.6x barlow on a 6" f8 frac and 10" f4.8 Newt.....beautiful.

[johnnyjetski]

Very Interesting thread everyone!

47 Tucanae for me is one of the most amazing sights in the southern sky.
I never cease to enjoy looking at it and imagining what it would be like being closer to an environment like that.
It fires up my imagination and hopefully others when I show it through my scope.

JohnS

[bigjoe]

Hi Matt.

I must put a Binoviewer on my to buy list and try it in a 10" sct I have; I think i'll be in for a wonderful surprise!

cheers bigjoe.

[m11]

Hi Matt,

Never thought of a Binoviewer to view these beauties in particular. Does the Binoviewer enhance the view in other ways as well?

Wondering if its worth getting a binoviewer and what objects really stand out in particular with them?

Thanks,

Mel

[m11]

Was going to add, thanks to everyone who have responded. I am very new to astronomy and found everyone so helpful.

I didn't expect so many people willing to impart their knowledge and take time out to reply.

My sincere thanks :thanx:

Mel

[bigjoe]

Hello Mel once again.

Glad to help it's just soo hard starting out, esp if you want to get into astrophotography (it's a minefield for the unwary).

I myself see binoviewers more as a luxury than a necessity, but a lot of people swear by them when viewing , as if things appeared more3D like.

Who knows for sure; better go to a star party before spending and find out!!

bigjoe.

[ngcles]

Hi All,

Photo says it all ...

[MichaelSW]

I have this AAO image of 47 Tuc as the background on my Desktop Screen at work. Many of my work mates have stopped to ask about it.

[bigjoe]

Ngcles Hello !

Love it. Now maybe you've started something here!! I have to think of something for my cars!!

Hmmm: NGC 6752 ,no, NGC6067, no Arggg!!!

[Allan]

I consider Omega Centauri the king and 47 Tuc the queen. I've had the courage to sketch the king,

http://www.iceinspace.com.au/forum/attachment_browse.php?a=184097

but I think the queen is more complex, and I haven't had a go at that one yet.

[jenchris]

I took these pics withy 8 inch lx90 a few years ago now
.
I picked both out of the sky as about equal brightness to my eyeball in my garden.
Once i looked at them in the eyepiece, I realised that the overall light was similar but the gradient on tuc 47 was really pronounced.
Though I can't get over the awe I felt watching omega centauri in my own kit.
It was a life changer.

[Atmos]

On Friday night I compared the two one after another. I can understand what you mean about 47 Tuc appearing brighter because it is far more compact. I preferred looking at Omega Cent though. Looked better through my 5" refractor at a dark site than the 10" cat in the city :)

[The_bluester]

Funny enough, Saturday night finally gave me the chance to refresh my memory. Pretty much what I remembered, whatever the stats say, 47 Tuc just provides more impact for me. Omega Cen is visually bigger but just somehow does not capture my eye in the same way.

[m11]

Hey Colin,

Yah, that is a better description in that 47 Tucanae has a more dramatic impact due its compact core.

The urban skies really kill alot of awesome deep sky stuff. I have found it hard to get out to dark skies on a regular basis due to family commitments.

Mel

[m11]

Hey Paul,

Yep, I feel the same way for 47 Tucanae as it just feels its more dramatic for me where as Omega Centauri is more spread out.

Mel

[raymo]

Like Paul, I prefer 47 visually, but have never been able to get an image
that does it justice; I think I need more focal length.
raymo

[MattT]

I use the binos on Planets and the Moon mostly. Its more relaxing, for me, to sit and look with two eyes. I compared binos with 15mm GSO Superview eyepieces and various Barlows to Pentax XW 10 7 5 and 3.5mm eyepieces for quite a long time (months) and came to the conclusion the Binos were better on Solar system and bright DSO's. I sold the XW's and haven't missed them at all.
Bright DSO's include the Orion Nebula, Carina Nebula, Globs, open star clusters etc.
For dimmer DSO's mono is better.
Matt

[m11]

Thanks for sharing your experience Matt. Something I will look at in the future as I havent done much planet viewing.

Mel