National Optical Astronomy Observatory
Tucson, Arizona
For more information:
Douglas Isbell
NOAO Public Information Officer
(520) 318-8214,,

A sharply detailed image of the northwest portion of the Andromeda galaxy, M31, demonstrates the power of an on-going sky survey project sponsored by the National Optical Astronomy Observatory (NOAO).
This image of M31, the closest spiral galaxy to our own Milky Way, was taken by Phil Massey of Lowell Observatory, Flagstaff, AZ, and Nichole King of the Space Telescope Science Institute, Baltimore, as part of a survey project titled "The Resolved Stellar Content of Local Group Galaxies Currently Forming Stars."
This color image shows 20 percent of the planned survey region in M31. It is constructed from two overlapping 35 arcminute x 35 arcminute fields. Blue stars are the youngest, most luminous and most massive, while yellow and red stars show a somewhat older population.
The goal of the survey is to produce detailed, uniform photometry of roughly 100 million stars in the Local Group of galaxies, including M31, M33, NGC 6822, IC 1613, IC 10, WLM, Pegasus, and Phoenix.
The survey uses Mosaic CCD cameras on the National Science Foundation’s Mayall 4-meter telescope at Kitt Peak National Observatory near Tucson, AZ, and Blanco 4-meter telescope at Cerro Tololo Inter-American Observatory near La Serena, Chile. This image is a combination of two from the Mayall.
The image is available on the Internet linked from this press release at:
More details about the project may be found at:
For further information about the survey projects conducted by the NOAO, see:
Kitt Peak and Cerro Tololo are part of the National Optical Astronomy Observatory, which is operated for the National Science Foundation by the Association of Universities for Research in Astronomy (AURA), Inc.
NOAO is operated by the Association of Universities for Research in Astronomy, Inc., under cooperative agreement with the National Science Foundation.