Data for M31: m = 1.04, vrot = 275 km/s, dM31 = 770 kpc.
For M31, log10 (vrot) = __________
The apparent magnitude, md, if M31 were at a distance of the 6 galaxies is __________
How many magnitudes dimmer is this than M31's real apparent
This is Δm in the formula for d given in the instructions.
The distance is then d = ___________ (See the instructions for the appropriate formula.)
The average vexp for the 6 galaxies = ___________
H0 = vexp/d = __________ (The usual units for this are km/s/Mpc, so convert d to Mpc first.)
For many years, a veritable blood feud has been going on
between various astronomers who think that this number is either
50 or 100. More recently there seems to be a consensus developing
that it is somewhere in between. Where does your value fit in?
Image scale = 90"/(length of 90" line) = __________ arcsec/mm.
Table 2: Mass-to-Light Ratio
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