The Cepheid Variable M31_V1: Hubble's First Cepheid

The AAVSO is pleased to note the publication of the Hubble Heritage images of the Cepheid Variable V1 in M31 this past month.  At the 100th Spring Meeting of the AAVSO, cohosted by the American Astronomical Society in Boston, the Hubble Heritage team finally released their work on Edwin Hubble's first Cepheid "V1" in the Andromeda Galaxy.  This image set -- a series of images showing this star changing in brightness over a span of about 30 days -- was obtained in part with the help of several observers of the AAVSO, who provided STScI with phasing information about this star.  With the help of an ephemeris created using AAVSO data, four HST visits were scheduled that imaged this star at its brightest and faintest.  The resulting HST observations were published by the Hubble Heritage team at a press conference at the AAS meeting attended by several AAVSO observers.

You can find the Hubble Heritage release and related materials at this website:

We're thrilled to see the work of the amateur observer community put to such use, and we congratulate both the participating observers and Hubble Heritage on the release of this beautiful image!

However, our work isn't done yet.  The AAVSO observers put together a wonderful data set on this star, and we're preparing a scientific publication presenting the light curve and ephemeris for the use of future observers.  M31_V1 hadn't been studied in several decades, and the observations of AAVSO observers provide an important new dataset for the study of this star that we'll share with the astronomical community.  Look for this paper later in 2011!