1325+47B SUPERNOVA 2005cs IN NGC 5194 (M51)

We have been informed by the Central Bureau for Astronomical Telegrams (IAU Circular 8553) of the discovery of a supernova in NGC 5194 (M51) by Wolfgang Kloehr, Schweinfurt, Germany, at unfiltered CCD magnitude ~14 on images taken June 28.907 and 28.928 UT, using a 0.20-m reflector.

W. Li, University of California at Berkeley, reported (IAU Circular 8553) that the new object was confirmed at CCD mag ~13.5 on an image taken with the Katzman Automatic Imaging Telescope (KAIT) at Lick Observatory on June 30.25 UT.

Li also reported (IAU Circular 8553) that the KAIT image yields the following position for SN 2005cs, which is 67.3" south of the nucleus of NGC 5194:

R.A. 13h 29m 52.85s Dec. +47o 10' 36.3" (2000)

End figures provided by H. Yamaoka, Kyushu University, and measured by K. Itagaki, Teppo-cho, Yamagata, Japan, on his unfiltered CCD image taken June 30.484 UT using a 0.60-m telescope are: 52.78s, 35.7" (IAU Circular 8553).

Spectroscopy obtained by R. Hutchins on June 30.23 UT with the F. L. Whipple Observatory 1.5-m telescope (+ FAST) and reported by M. Modjaz, R. Kirshner, and P. Challis, Harvard-Smithsonian Center for Astrophysics, indicates that SN 2005cs is a young Type-II supernova (CBET 174, IAUC 8555).

A possible progenitor has been identified by
- M. W. Richmond, Rochester Institute of Technology (IAUC 8555), who indicated that if the progenitor is indeed the young blue star he identifies, SN 2005cs may evolve like SN 1987A, which was also a type-II supernova with a blue progenitor.
- W. Li, University of California Berkeley; S. D. Van Dyk, Spitzer Science Center, California Institute of Technology; and A. V. Filippenko, University of California Berkeley (CBET 175). For details, please see the IAU Circular and Central Bureau Electronic Telegram cited.

A Thompson/Bryan supernova search chart for NGC 5194 showing the location of SN 2005cs and having a PEP(V) sequence is available at the following URL:

http://www.aavso.org/tmp/ngc5194-tb.png

Please use this chart to observe the supernova, and report your observations to the AAVSO as 1325+47B SN 2005CS.

Observations reported to the AAVSO include:
June 15.20 UT <~19 CCD, KAIT image (IAUC 8553); 20.598, <~17.0 CCD, Itagaki (poor conditions, IAUC 8553); 27.933, 16: CCD, W. Kloehr (IAUC 8553); 27.933, 16.6 CCD (unfiltered; red magnitude), P. Birtwhistle, Great Shefford, England (via G. M. Hurst, Basingstoke, England, on IAUC 8555); 30.484 14.3: CCD, K. Itagaki (IAUC 8553); 30.860 14.0 CCD, P. Corelli, Udine, Italy; 30.8800, 13.64 CCD, T. Scarmato, Calabria, Italy; 30.9264, 13.92 CCD, D. Rodriguez, Madrid, Spain; Jul 1.2910, 14.2 CCDV, R. Royer, Springville, CA.

Notes:
a. Nothing seen on a Digitized Sky Survey image, an `LRGB' image taken by R. Muendlein on Feb. 5, or CCD images taken by Kloehr on May 11 and 26.

b. NGC 5194 was host to 1325+47 SN 1991I (see AAVSO Alert Notice 183).

For more information on the discovery, spectroscopy, and possible progenitor of SN 2005cs, please see IAUC 8553, IAUC 8555, and CBET 175.

Congratulations to Wolfgang Kloehr on his discovery!

Thank you very much for your astronomical contributions and your efforts.

Good observing!

Elizabeth Waagen
Senior Technical Assistant

------------------------------------------------------------------------------
SUBMIT OBSERVATIONS TO THE AAVSO

   We encourage observers to submit observations via our web site (online
data submission tool WebObs), or by email in AAVSO format to
observations@aavso.org. If you do not have AAVSO Observer Initials,
please fill out the following URL so we may assign them to you.

      http://www.aavso.org/observing/submit/apply.shtml

   The answering machine at AAVSO Headquarters is on nights and weekends;
use our charge-free number (888-802-STAR = 888-802-7827) to report your
observations, or report them via fax (617-354-0665).

For information on the free publication AAVSO MyNewsFlash and to
subscribe, please visit the following AAVSO webpage:

http://www.aavso.org/publications/newsflash/myflash.shtml

To unsubscribe, please visit your WebObs page and delete your MyNewsFlash
profile.

------------------------------------------------------------------------------