>Can anyone out there explain to me if it is possible to determine the approximate
>distance to a galaxy using the data that Guide supplies?
>And if it is possible, what are the steps?

...you can take the distance modulus : apparent magnitude (m)- absolute magnitude(M)
of the galaxy and then, get the distance from that value. Ex.the absolute mag for M87
is -21.5 and his app.mag is 9.5 giving a m-M of 31. Then compute the distance by
solving : log D(parsec) = (m-M+5)/5 (neglecting absorption) = 15.8 Mpc (~ 50 M a.l.).

...or you can consider relative distance instead of absolute distance. This method is
for the outermost galaxy i.e. for those that are not affected by a peculiar velocity.
We take the heliocentric radial velocity of the galaxy, given in Guide. We assume
that the galaxies are on the Hubble flow, and then, find the relative distance with
the Virgo cluster wich has a typical RV of 1,200 km/s at a distance of ~ 50 Ma.l. Ex.
the galaxy x has a RV of 5,000 km/s. The relative RV with the Virgo cluster is then
5,000/1,200 = 4,16.


\ mario