Quoted from SEDS:
Discovered by Giovanni Batista Hodierna before 1654.
Messier 38 (M38, NGC 1912) is one of the three Messier open clusters
in the southern part of constellation Auriga.
Lying only 2.5 degree northwest (preceding) of
M36, this cluster
was silently discovered by
Hodierna before 1654, and independently found by
Le Gentil
in 1749.
Charles
Messier included it
in his
catalog on September 25, 1764.
Its brightest stars form a pattern resembling the Greek letter Pi, or
(according to Webb) an "oblique cross". At its distance of 4,200 light
years, its angular diameter of about 20' corresponds to about 25 light
years, similar to that of its more distant neighbor
M37. It is of
intermediate age (about 220 million years according to the Sky Catalog
2000) and contains a yellow giant of mag 7.9 and spectral type G0 as its
brightest member - this corresponds to an absolute magnitude of -1.5, or
a luminosity of 900 suns. For comparison, the Sun would appear as faint
as only mag 15.3 from the distance of M38 !
Kenneth Glyn Jones has a significantly smaller distance of only 2,750
light years. The Trumpler class of M38 is given as II,2,r by all
sources. |
