Under the sky glow of a major urban center (Bortle class 8- white zone), where there is no possibility of seeing even the brightest parts of the Milky Way, it is always surprising to me that any galaxies can be seen. The night of this observation and sketch was a night of better than average transparency. The faintest stars visible near the zenith were about 4th magnitude. The brighter spring galaxies are indeed detectable and somewhat visible, but can be challenging to locate by star hopping in the gray background at lower magnifications. At higher magnifications the contrast does improve and one can see some detail in the cores of galaxies if you stay with them for extended periods of time. At visual magnitude 8.5 Sab spiral galaxy M-64 shows its core and dark dusty star forming region (black eye) pretty well. Astronomers tell us it is likely the dark star forming region formed some one billion years ago as the spiral galaxy collided with a small companion. This is at least one hypothesis proposed in the 1990’s. It is also worth noting that the inner and outer parts of this galaxy are rotating in opposite directions contributing to the increased rate of star formation along the black eye. M-64 is between 17 and 19 million l.y. from us and measures 51,000 l.y. across. The galaxy may be a member of the M-94 group of galaxies also called the Canes Venatici I (Schmidt and Boller) cloud and is located in the constellation of Coma Berenices not far from 35 Comae Berenices.
K.H. Schmidt and T. Boller, 1992. Nearby Galaxies. I. The catalogue. Astronomische Nachrichten, Vol. 313, No. 4.
Date and Time: 6-4-2010, 4:00-4:40 UT
Scope: 18” f/5 Dobsonian. 21mm eyepiece (108x) and 9mm eyepiece (254x)
8”x12” white sketching paper, 4B and HB graphite pencils,
blending stumps, gum eraser, scanned and inverted
Seeing: Pickering 7/10
Transparency: Average to above average 3/5-4/5
Low humidity, temperature 15°C (60°F)