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Old 10-07-2012, 02:50 PM
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Vegeta (Ibrahim)
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M104 and NGC 5128

Hi, I was just recently observing M104 for the first time in a large scope (12") and noticed that it is pretty bright for a galaxy. The belt that bisects the galaxy was visible. I turned the scope around at NGC 5128 and noticed that it was roughly the same brightness as M104 . I always thought that NGC 5128 had a higher surface brightness and magnitude and would therefore, be much brighter.
they were both observed from an area with relatively low light pollution and were observed for 3 days, each with modrerate seeing.

Does anyone know why i'm seeing this?
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Old 10-07-2012, 04:55 PM
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Back Yard Boy (Kevin)
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I must say that the last time I looked at the M104 and Centaurus A galaxies, I thought they both appeared to be of similar brightness. If there is any difference in brightness it certainly is not apparent to my eyes. I have a 12" DOB.
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Old 10-07-2012, 06:11 PM
Rob_K
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Strange, their integrated magnitudes are similar (NGC 5128 a touch brighter) but NGC 5128 is a much larger object and its surface brightness always seems considerably less than M104 to me.

Might be a 12" thing! Observing through a little scope, M104 is a bright little gash at low powers, but the dust lane can be seen. NGC 5128 is seen as a much bigger dull nebulous object that looks like a fuzzy pacman on a bad night but on a good night it is larger again and the dark lane can be seen right through. M104 holds really well at higher powers making the dust lane clearer while NGC 5128 is not worth viewing at higher powers, yuk!

Just my experience, they're like chalk and cheese to me.

Cheers -
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Old 10-07-2012, 09:45 PM
clive milne
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5128 is a galaxy that really benefits from aperture.

Through a 25" mono or 20" binocular the dust clouds on the main edge of the central band become easily resolved leading to a stunning spectacle.

It is one of the best objects in the sky for this class of instrument, 104 less so.
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Old 10-07-2012, 10:10 PM
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Paddy (Patrick)
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I have to say that subjectively M104 is brighter to my eye. I wonder how much of the effect is that the centre part of NGC 5128 is much brighter than the outer parts of the halo. It took me a while to work out when I first started observing it that the reason it looked so different in images was that a lot more of the disc is visible than it is even in a 16" scope.
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Old 10-07-2012, 10:41 PM
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NGC 5128 has always struck me as somewhat underwhelming, whereas comparatively M104 slaps you in the face. I actually never understood why northern hemisphere observers foam over NGC 5128, it really is quite low surface brightness and the lane takes some effort to see under any light pollution. Is it the mystique of it being a far southern object?

M104 is a bright gash (good choice of words Rob!) and as the surface brightness is much higher the dark lane stands out better, albeit much smaller than the big broad highway bisecting 5128.
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Old 11-07-2012, 05:33 PM
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Vegeta (Ibrahim)
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thanks for the replies, I agree M104 is pretty impressive and handles magnification pretty well, But NGC 5128 is best for me at around 50x - 100x magnification (even then, M104 still takes the lead, I don't know why northern observers complain!). I must admit, in terms of ease, NGC 5128 is really easy to find for me.
M104 sits in the middle of no where
I havn't tried looking for NGC 253 yet, it's my spring/summer target, so if anyone has seen it, please leave some feedback
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Old 11-07-2012, 07:10 PM
Rob_K
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Quote:
Originally Posted by Vegeta View Post
I havn't tried looking for NGC 253 yet, it's my spring/summer target, so if anyone has seen it, please leave some feedback
Hi Ibrahim - 253 is a behemoth compared to M104, it'll be big and bright in your 12" scope. Should be easier to find too. Lots of galaxies in that general area - NGC 247 is quite close but is smaller and a veritable 'ghost' compared to 253! NGC 55 is a treasure, a big galaxy not much less impressive than NGC 253 and with a distinctly lop-sided appearance. Good luck & I look forward to your report when the time comes!

Cheers -
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Old 12-07-2012, 07:57 AM
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orestis
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I have not observed for quite some time, but through my 12'' dob I would say that M104 is slightly brigher but that is probably because it is much smaller.Considering favoritism,both are equally impressive probably leaning towards M104.

I hope to try to view these wonderful galaxies soon.

Regarding Ngc 253, it is quite spectacular in a 12'' you should be able to see a considerable amount of detail if your at a dark site.Also try and view Ngc 55 it is a very unique galaxy, a joy to observe.

Clear skies
regards Orestis
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