Andromeda I

Dwarf Spheroidal Galaxy Andromeda I (PGC 2666), type dE3 pec ?, in Andromeda

RA:: 00 : 45.7
Dec:: +38 : 00
Type:: dE3 pec ?
RV:
Distance:: 3000 kly
Apparent Dimension:: 2.5 x 2.5 arc min
Diameter:
Brightness:: 13.2
Abs. Mag:
Mass:

Andromeda 1, or And I, is a dwarf spheroidal galaxy, and a companion of the Andromeda Galaxy M31, situated roughly 3.5 degrees south and slightly east of the great neighbor, corresponding to a projected distance of about 150,000 ly. From us, it is slightly more distant than the great galaxy, according to van den Bergh 2000.

And I was discovered by Sidney van der Bergh on photographic plates taken in 1970 and 1971 with the Palomar 48-inch (1.2-meter) Schmidt telescope, together with And II, And III, and the presumable non- or background galaxy And IV (van den Bergh 1972).

Our image was obtained by Martin Germano. It is a 125-min exposure on hypered Kodak Tech Pan 2415, taken through his 14.5-inch f/5 Newtonian telescope in September 2001. Martin writes: "This dwarf elliptical Galaxy in Andromeda is really faint! Just a small scattering of faint dots near the center of this image."

References:

Sidney van den Bergh, 1972. Search for Faint Companions to M31. Astrophysical Journal, vol. 171, pp. L31-L33 [ADS: 1972ApJ...171L..31V]
Sidney van den Bergh, 2000. Updated Information on the Local Group. Publications of the Astronomical Society of the Pacific, Vol. 112, No. 770, pp. 529-536 [ADS: 2000PASP..112..529V]