A 38 minute exposure taken with an SBIG STL-1301E CCD camera thru our 20-inch telescope. The field of view is about 12x16 arc minutes with North at the top.
Charles Messier (December 17th, 1780): 'A cluster of small stars which contains some nebulosity in the Whale and on the parallel of the star delta, reported of the 3rd mag. but which M. Messier estimates to be of the 5th. M. Mechain saw this cluster on the 29th Oct. 1780, in the form of a nebula.
W. Herschel: (1814) Such a cluster of stars as the 77th of the Connoissance des Temps will put on the stellar appearance when it is viewed in a very good common telescope.
Rosse: (Dec 1848) A blue spiral.' (Oct. 29th, 1851) 'The central part is flatter on the f. side.' (Nov. 24th, 1851) 'The central part is, I am nearly sure, spiral."
Spiral Galaxy M-77 is one of the most unusual objects in Messier's catalog. However, its visual appearance in a 10-inch telescope is far from spectacular. It appears as a small, round, nebulous patch, with a small, bright, almost star-like nucleus. There is an 8th magnitude star just to the west. This star and the tiny nucleus may be what convinced Messier that this was "A cluster of small stars which contains some nebulosity...." P.Mechain, Messier's friend and rival, first observed M-77 in October 1780. However, it wasn't until 1848 that lord Rosse recognized it as a 'spiral nebula'
M-77 is the brightest and closest of the Seyfert galaxies. In 1943 Seyfert described this class as spiral galaxies with nuclei that showed emission lines in addition to the normal continuous spectrum. This implies that there is a cloud of rapidly expanding gas in the nucleus. Observations with X-ray and radio telescopes support this. M77, as well as other Seyfert galaxies, is very bright in the infrared, and its brighness is variable. It has a small energy source in its nucleus that is pumping out more energy than several millions of supernovae. Most astronomers now consider Seyfert galaxies to be older versions of the much more energetic, distant, and young, quasars. The central energy source is most likely a billion solar mass black hole which is consuming gas and whole clusters of stars.
M77 is the largest member of a small group of galaxies, which includes spiral galaxies NGCs 1055 and 1073, as well as five small irregular galaxies. NGCs 1087, 1090, and 1094 appear close to M-77, but they are background galaxies.
George Normandin, KAS
March 26th, 2007