Mass of NGC 1097 Galaxy I've been looking all over the internet for this and can't seem to find a reference.  Can anyone refer me to a paper citing the mass of NGC 1097 based on luminosity?
 A: This paper reports modelling of NGC 1097, and they use a figure of around $10^{10}$ solar masses. They cite a paper that isn't available online.
I have to confess this seems small to me. It's only 1% of the mass of the Milky Way.
A: You have to distinguish between stellar mass and gravitating mass. 
The quoted Milky Way mass includes dark matter.

Despite searching in the literature, I have yet to find reliable apparent magnitudes and good distance estimates for NGC 1097. 
The total Blue luminosity of this galaxy is near to Minus B-band absolute magnitude -21, but only ballpark estimates can be made from the existing data. NGC 1097 is significantly more luminous than our own Milky Way Galaxy!
Here is the best that I can do, insofar as estimating the distance and the absolute magnitude and the luminosity of NGC 1097:
http://www.iceinspace.com.au/forum/showthread.php?p=1164458
Unfortunately, NGC 1097 is one of many bright southern galaxies for which there are no "high accuracy"(+/- 10 percent) distance determinations using methods such as TRGB and Cepheids. 
People are writing lots of papers on N1097 without having a good idea of how far away it is!!

A more accurate way to estimate the mass, in the form of stars, in a given galaxy, is to base the luminosity estimate of a galaxy on the Near-infrared magnitude, for instance the H or K band magnitude. 

Sincerely yours,
Robert
alias madbadgalaxyman
