M81 on 02-27-2008
Done with my 17.5 inch scope and SBIG ST-9E CCD camera
M81 is the brightest galaxy of a nearby group called the M81 group. A semi-recent close encounter with M82 has dramatically deformed M82 and has also left traces in the spiral pattern of M81 the brighter and larger galaxy.
Using the Hubble Space Telescope, a team under Wendy Freedman of the Carnegie Institution of Washington has investigated 32 Cepheid variables in M81 and determined the distance to be 11 million light years.
On March 28, 1993, a supernova (1993J) occurred in M81. The remnant of this supernova was imaged in the radio light at 3.6 cm wavelength for about six to 18 months after the explosion.
Investigations performed in 1994 have given evidence that M81 probably has little dark matter because its rotation curve was found to fall off in the outer regions.
OBJECT = 81
TELESCOPE = 17.5 inch f3.23
CAMERA = ST7-E
OBSERVER = Rusty Fletcher
LOCATION = Seguin Outdoor Learning Center
DATE (Yr-Mo-Dy) = 2004-12-10
TIME (UT) = 10:07:49
TOTAL EXPOSURE = 540 sec
IMAGES STACKED = 18
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