[sac-forum] Re: Messier Marathon results questions

---- David Hofland <hofland@xxxxxxx> wrote: 
> M-77 is pretty low surface brightness and relatively even consistancy, its 
> highly unlikely that you were seeing M-77's core.


Actually, the core of M77 is one of the brightest in the sky.  There is a very 
large gradient in the brightness from this core to the outer edge.

I Googled "surface photometry" and M77, and it turned up a good paper that 
shows the isophotes.

http://adsabs.harvard.edu/full/1987PASJ...39..411I

The V-band photometry is in Figure 3b.  You can see the huge brightness 
gradient.  That innermost isophote is 15 mag/sq. arcsec, and it's surrounded 
closely by isophotes of 16 and 17 mag/sq. arcsec.  The core of such a galaxy 
looks pretty bright in a medium-sized telescope.

Tom

Other related posts: