[vsnet-alert 3727] KM Lac in outburst

[Patrick Schmeer <extpasc@rz.uni-sb.de>]

CCD magnitudes obtained by P. Schmeer, Bischmisheim, Germany:
LACKM 991117.275 180C  Scp
LACKM 991118.180 164:C Scp
LACKM 991119.095 158C  Scp
Sequence:   USNO-A2.0 (red magnitudes)
Instrument: IRO (0.5-m RCT + AP-8)

KM Lac is currently undergoing its first ever outburst recorded on CCD.
The dwarf nova is about 3.7" WNW of the following USNO-A2.0 star:
221349.831 +552824.43 (2000.0) 14.4 15.1
I get the following positions (reference: GSC) from the outburst image:
KM Lac     22:13:49.43 +55:28:25.9
USNO star  22:13:49.83 +55:28:24.4
Both stars are visible on the DSS image.
In recent years Lasse Jensen, Tonny Vanmunster, and Makoto Iida reported
KM Lac at mag 14-15, but those were observations of the USNO star.
Based on the outburst dates (see below) given by Miller and Wachmann
(1971, Ric. Astron., 8, 12) I have derived a mean cycle length of 133
days for KM Lac = VV 347 (values of 76 and 56 days seem also possible
but less likely).

Time-resolved photometry and spectroscopy during the current outburst
are strongly recommended.

Regards,
Patrick

P.S.:
Excerpt from vsnet-obs message No. 1723 (Taichi Kato, 1995 Dec. 19):
-----------------------------------------------------------------------------
   As far as I know, there is no published spectrum of KM Lac.  My exami-
nation of the discovery paper seems to confirm the identification by
Downes & Shara (1993).  The discoverer gave the following outbursts dates and
magnitudes.  Has the system changed its properties dramatically, or was there
any problem in the original chart?

     JD         mpg
   2430256     14.8
     32766     14.8
     33156     14.9
     33276     15.0
     33442     14.8
     33975     14.8
-----------------------------------------------------------------------------

VSNET Home Page

Return to Daisaku Nogami

---

vsnet-adm@kusastro.kyoto-u.ac.jp