Karachentsev, who knows more about the "within 10 Megaparsecs" sample of galaxies than anyone else (having made a lifetime study of it!) gives the following parameters for this galaxy in his
''Updated Nearby Galaxy Catalog"
( see:
https://heasarc.gsfc.nasa.gov/W3Brow...istance_method
)
Apparent B (= "blue") magnitude = 14.11
(note: I wouldn't bet on this being particularly accurate. Could even be half a magnitude out. )
Distance = 7.9 Megaparsecs
(this distance measurement is based in its membership of a Galaxy Group which has other members with actual distance estimates)
B Absolute Magnitude (at the assumed distance) = -16.1
(note: this Absolute Magnitude estimate has to be regarded as merely an indicative figure for the luminosity of this galaxy......
The distance , and even the apparent B magnitude, both have considerable uncertainty. But the parameters of this galaxy are sufficiently well established to show that this is indeed a Small Galaxy that is very much in the foreground of the major clusters of galaxies )
(( The aforementioned catalog is one of the most useful, for relatively nearby galaxies.))
INFO ADDED IN EDIT::
Additional data on UGC 12588, taken from Tully's "Nearby Galaxies Catalogue"(1988)
(this catalogue is available at the ""VizieR" facility at the CDS Strasbourg website)
Hubble Type = type Sdm
Velocity distance (based on a Hubble Parameter of 75 km/s/Mpc)
= 9.3 Megaparsecs
Mass of HI (total mass of the neutral Atomic Hydrogen gas, in this galaxy)
, equals 2.88 x 10E8 solar masses.
madbadgalaxyman's commentary;
Tully's radio observations of the neutral Atomic Hydrogen gas in this galaxy, indicate that it contains a modest mass of neutral atomic hydrogen.
I would suppose that it is this gas that is forming the bright blue stars, rather than molecular hydrogen gas, as there is unlikely to be enough dust in this galaxy to shade the molecular hydrogen from starlight.
(low metallicity and low dust content, is a marker of a small galaxy!)