British Astronomical Association

New SN in M51

Guy Hurst reports in The Astronomer E-circular E2124 the discovery by Wolfgang Kloehr, in Germany of a 14th magnitude supernovae in M51 on June 28.91.
Further CCD images by Richard Miles from Golden Hill Observatory shows a V mag of V=14.53 on 2005 June 30.993 showing the object may well be fading already.

In addition, Maurice Gavin has captured a spectrum which can be viewed at
http://home.freeuk.com/m.gavin/2005cs.htm

The TA report is as follows (with thanks to Guy Hurst):-

SUPERNOVA 2005cs IN M51
Wolfgang Kloehr, Schweinfurt, Germany, reports his discovery of a magnitude 14 apparent supernova in Messier 51 (NGC 5194). It was recorded on CCD frames of June 28.91 and 28.93UT using a 0.20-m reflector. It may also have been present on June 27.93UT near magnitude 16.

The discoverer provides the following position:
RA 13h 29m 53.37z DEC +47 10'28.2" (2000), 15" W and 78" S of the host galaxy's centre. Kloehr adds it was not present on May 11 and May 26 and is also absent from the Digitised Sky Survey.

A KAIT image obtained on June 30.25UT confirms the presence of the new object at about magnitude 13.5 with end figures:
RA 52.8s DEC 36.3"

Hitoshi Yamaoka, Japan adds:
SN 2005cs is located on the southern arm of "Whirlpool Galaxy" M 51. On the pre-discovery image, there is a bright star cluster and H II region. It is possibly a gravitational-collapse of a massive star, but the prompt spectral classification is urgently needed, as well as follow-up photometry.

Editor: Could I please request all our observers to check any recent images of Messier 51, a popular deep sky object. If the presumed supernova is present please e-mail images with full supporting details. If your images obtained during the last month are negative, please just send date, time and limiting magnitude together with instrumental details.

Roger Pickard
Director, BAA Variable Star Section.

Ref: BAA electronic circular No. 00191