[vsnet-alert 251] on identification and current outburst of PY Per

[tkato@kusastro.kyoto-u.ac.jp]

    The position of dwarf nova PY Per, currently reported to be in bright
outburst by M. Iida (VSOLJ, cf. vsnet-alert messgae on Oct. 6), was measured
by him from Ouda CCD frames.  He obtained the following accurate position of
the outbursting object.

    02h50m00s.17  +37o39'22".5  (J2000)  (5 GSC stars, residual 0".1)

    This position corresponds to the south-east faint companion in Downes
and Shara (1993) finding chart.  D. Nogami has checked POSS I and concluded
that the fainter component was actually outbursting at the epoch of POSS I.
(This seems to be slightly contradictory to the discovery notice by
Hoffmeister, 1966, Astron. Nachr. 289, 139.)

    The outburst amplitude of PY Per should be thus much larger than
previously believed (may be a TOAD?).  This suggestion seems to be
strengthened by the possible discovery of superhumps by Ouda CCD photometry,
which has yielded repeated dip-like fadings separated by 0.058 day.
The identification of PY Per as an SU UMa-type dwarf nova now seems to be
acceptble, although precise determination of the period would require
further analysis and observations under conditions less affected by the
moonlight.

Regards,
Taichi Kato & Ouda team

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