GALEX M31 Novae

M31 Novae Observed by GALEX

Using the nova list from Pietsch et al. (2007) we generated lightcurves from the GALEX epochs that overlap with the nova outbursts. Of the 20 novae that were in outburst and covered by GALEX imaging, 14 were convincingly detected: 2003-01c, 06a, 06b, 06c, 06d, 07a, 07b, 08a, 08c, 09a, 09b, 2004-05a, 07a, 08c. Several more may possibly be measured with more sophisticated photometry, required by proximity to M31's nucleus. See the finder charts to bolster our detections and to see which novae are effected by proximity to the nucleus.

UV Photometry was performed using the IDL aper.pro routine in two passes. The first pass is used to decide if the nova is detected and uses a 2 pixel radius measurment aperture. If the signal-to-noise ratio is greater than three, the nova is considered detected. The detected novae are then measured again with a 1 pixel radius aperture (R=1.5") and the fluxes are corrected to full flux using the aperture corrections from Patrick's GALEX calibration paper. The sky annulus used in both passes is from 5 to 15 pixels. In the plots below the detected novae are plotted with a blue diamond (NUV) or a purple triangle (FUV), while the non-detections are plotted as limits with the corresponding color.

Optical Photometry was taken from Pietsch et al. (2007) which is a compilation from various sources of mostly R-band measurements with a few V and Ha measurements thrown in.

Nova UV and Optical Light Curves

The epochs of the GALEX images are indicated by the vertical dashed lines. The epoch of the putative nova outburst is indicated by the vertical dotted line. If a nova was off the edge of the image for a given GALEX epoch, it is indicated by a black plus-sign near the bottom of the plot.

Last updated, 06 Sep 2007

Please send questions or comments to Don Neill at neill AT srl DOT caltech DOT edu