M 38 is one of the three Messier open clusters in the southern part of constellation Auriga. It is larger than M36, spanning about 21 arc minutes in the sky and thus overflows the top and bottom edges of my frame. This may be due to its greater age, about 220 million years, since open clusters tend to dissipate over time. It lies about 4,200 light years from Earth 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 !


Image taken November 24, 2009, with the C-14 operating at F:7. Exposure is 1 minute.