The Andromeda galaxy, M31 and its companions
AAO image reference 'Caltech M31'.    « Previous || Next »

Caltech M31
Top left is NE. Image width is about 2 degrees   © 2000-2002, Malin/Caltech, Photograph by Bill Miller.
This image is only available as a digital file.


M31 is the finest and nearest large spiral galaxy in the sky, about 2 million light years away. It has several close companions, the most obvious of which are the compact elliptical galaxy M31 (NGC 221) at lower centre here, and M110 (NGC 205) at upper right. M 31 is a member of the Local Group of about 30 galaxies that includes the Milky Way and M31 as its most massive members as well as the two Magellanic Clouds.

This particular picture is of interest because it was one of the first-ever astronomical colour images and certainly the first of M31. The 120 minute exposure was made 50 years ago, in 1958 August 11 with the Palomar 48-inch Schmidt Telescope (now the Oschin Schmidt) by Mt Wilson and Palomar Observatories' William C. Miller. Miller used the then revolutionary Super Ansco reversal film which had a nominal speed of 100ASA. Caltech sent the original to me in about 1989 for re-mastering, which was done photographically in those pre-digital days. I have since digitally re-mastered the copy I made at that time. The quality of the picture as a large digital file is quite outstanding, indicative of the fine optics of a large Schmidt telescope and Bill Miller's patient guiding.

Entry from NGC 2000.0 (R.W. Sinnott, Ed.) © Sky Publishing Corporation, 1988:
NGC  205  Gx 00 40.4  +41 41 s  And  17.48.0  vB, vL, mE 165deg , vgvmbM; = M110 
NGC  221  Gx 00 42.7  +40 52 s  And7.68.2  ! vvB, L, R, psmbMN; = M32  
NGC  224  Gx 00 42.7  +41 16 s  And 178. 3.5  !!! eeB, eL, vmE (Andromeda); = M31 
Related images
INT 1.  The nucleus of M31, direct image
INT 2.  The nucleus of M31
INT 3.  The southern arm of M31 (NGC 224) and M32 (NGC 221)

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