A&A Supplement series, Vol. 126, December II 1997, 401-406
Received November 14, 1996; accepted April 2, 1997
,E.A. Magnier
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T. Augusteijn
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S. Prins
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J. van Paradijs
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W.H.G. Lewin
Send offprint request: E.A. Magnier: gene@astro.uva.nl
Astronomical Institute "Anton Pannekoek'', Kruislaan 403, 1098 SJ Amsterdam, The Netherlands
Center for High Energy Astrophysics, Kruislaan 403, 1098 SJ Amsterdam, The Netherlands
University of Illinois, Astronomy Dept. Bldg. 103, 1002 W. Green St.,
Urbana, IL 61801, U.S.A.
Astronomy Dept. 351580, University of
Washington, Seattle, WA 98195, U.S.A.
Massachusetts Institute of
Technology, Room 37-624, Cambridge, MA 02139, U.S.A.
European Southern
Observatory, Casilla 19001, Santiago 19, Chile
Physics Department,
University of Alabama in Huntsville, Huntsville, AL 35899, U.S.A.
Cepheid variables can be used for more than just a distance
indicator. Since the age can be determined from the period, they
can be used to trace the star formation history of a galaxy. We
have identified 130 new Cepheid variable candidates in M 31,
particularly along the spiral arm regions in the north-east of the
galaxy. These areas had not been searched for Cepheids in
the previous study by Baade and collaborators. The contamination of
our sample by other types of variables is low (< 3%). For V <
21, the completeness is 
53%. These Cepheids will be used
to explore the star formation history in M 31.
keywords: (stars: variables:) Cepheids -- stars: formation -- galaxies: individual: M 31 -- galaxies: stellar content -- (cosmology:) distance scale