Apparent Nova in M31 (1998)

According to IAUC No. 6981, M. Modjaz et al. (KAIT team) discovered an apparent nova in M31.

   00h 42m 37s.00  (J2000.0)
   +41o 16' 56".7

The reported unfiltered CCD magnitudes are

   1998 Jul. 19.5 <18.0
             23.5  16.1
             27.5  14.4
             31.5  15.6

Even considering the different CCD response to historical photographic records, the peak brightness of 14.4 is remarkable. The brightest novae ever discovered in M31 (disregarding SDOR stars and candidates) are:

                max  min   maxJD              name
  M31V0748  NA 15.0 (18.6 2448244(1990) - - - ShA33
  M31V0889  NA 15.0 (19.0 2445613(1983) - - - Nova1983
  M31V0942  NA 15.0 (18.  2438707(1964) - - - Nova57

The record of other M31 (classical) novae seems to indicate the existence of a sharp cut-off around 15.0 mag. Follow-up observations of the present anomalously luminous (apparent) nova are thus highly recommended. Although chance coincidence is very small, there may still exist a chance of a foreground variable.

Historically, two novae were observed close to the location of the present (apparent) nova. The difference in coordinates may safely preclude the possibility of a recurrence.

004234.9 +411639 (2000.0) M31V0849 N 17.5 (19.0 24701(1926) - - - Nova64
004238.8 +411703 (2000.0) M31V0868 N 17.2 (18.5 22608(1920) - - - Nova18

Chart

Nick James' image

http://www.astro1.demon.co.uk/images/m31_980729.jpg Link to the image

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