M31 = NGC224 ( 0h 42.7m +41°16´, 3.4 mag. )
Great Andromeda Galaxy was known since at least AD905 when it was listed by Al Sufi. It was observed by Messier on Aug. 3, 1764. At 2.3 million ly away, it is the most distant object visible to a naked eye (just 1° W of 4 magnitude star n Andromedae - see finder chart below). This spiral galaxy is the most massive member of the Local Group and contains over 300 billion stars. Its diameter is estimated at 180,000 ly. Two of its dwarf elliptical satellites, M32 and M110, are also on Messier list. Two more distant companions, NGC147 and NGC 185, are located in Cassiopeia. The brightest globular of M31, called G1, is located over 2°30' SW of that galaxy's center.
The above mosaic of M31 (including M32 and M110, as well) was assembled from 25 tiles. For each tile, five 60 sec. exposures were taken through infrared blocking filter on September 6, 7 and 11, 1999 from Sooke, B.C. using Celestron Ultima 8 SCT at f3.0 and Cookbook 245 LDC CCD camera. Individual images were combined with Multi245 software from Richard Berry and Corel PhotoPaint 8 was used to assemble the mosaic. Without counting calibration frames, that mosaic involved 125 min. of total integration time. This image shows stars down to 18.5 - 19 mag., including blue supergiants in M31 star clouds (like NGC206) !
The above image is reduced to 30% of the original. North is to the right.
The image of the central part of M31 below was taken on Dec. 13, 1998 from Sooke, BC using Cookbook 245 LDC CCD camera on Ultima 8 f6.3 telescope, autoguided with Cookbook 211 LDC CCD camera on piggybacked 500mm f8 telephoto lens. It is composed of W (10 x 2 min.) and CMY (4 x 2 min. each) integrations processed with AIP4WIN and further adjusted in Corel PhotoPaint 8 using Lab color model.
North is to the right as well.
Map created in Guide 7.0 - 9° x 10°. North is up.
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© Jan Wisniewski