The Discovery of a Possible Luminous Blue Variable in NGC 4414

We report the serendipitious discovery of a variable object, based on WFPC2 images of NGC 4414 retrieved from the HST archive. Photometric light curves show an increase of over 1.5 magnitudes in observations taken for the HST Key Project (Turner et al. 1998). In observations taken one year later, the object was not detected above the background (i.e. the spiral arms; v = ~ 25 mag). The peak brightness of this object, using a recently determined distance modulus to NGC 4414 (Turner et al. 1998) of 31.41 mag, is of order M_V = -10 mag. Given the limitations of this dataset it is difficult at present to determine conclusively the nature of this object. However, the shape of the light curve and peak brightness are suggestive of an eruption of a Luminous Blue Variable or a supernova. Follow-up HST WFPC2 imaging is scheduled for May/June 1999.