Skip to main content

Web Publications

AAVSO: Alert Notice 284 AAVSO HOME > publications > alerts

Alert Notice 284

                25 Birch Street, Cambridge, MA 02138 USA
                Tel. 617-354-0484       Fax 617-354-0665

                AAVSO ALERT NOTICE 284 (June 14, 2001)

1836-65 SUPERNOVA 2001cn IN IC 4758 (PAVO)

We have been informed by the Central Bureau for Astronomical Telegrams (IAU
Circular 7643) that R. Chassagne, Ste. Clotilde, Ile de Reunion, discovered
an apparent supernova on images taken June 11.95 and 12.85 UT at unfiltered
CCD magnitude about 14.8, using a 0.30-m reflector.  Nothing was seen at the
location of the supernova down to photographic magnitude ~21.0 on a Digital
Sky Survey image taken 1976 May 4.75 UT.

The object was confirmed at unfiltered CCD magnitude about 14.8 by R.
Santallo, Faaa, Tahiti, French Polynesia, who obtained images on June 13.531
UT, using a 0.2-m reflector (IAU Circular 7643).

According to Chassagne, SN 2001cn is located 2.6" west and 17.9" south of the
center of IC 4758, at the coordinates:

       R.A. = 18h 46m 17.84s   Decl. = -65 degrees 45' 41.8"  (2000)

Santallo gives the supernova's offset as 1.8" west and 17.4" south of the
nucleus, with corresponding end figures of 17.88s and 41.8".

Accompanying is an AAVSO Preliminary chart (approximately 'f' scale) of
IC 4758, based on the Digital Sky Survey and magnitudes from the USNO A2.0
Catalog and showing the location of SN 2001cn, prepared by K. Malatesta,
AAVSO Headquarters.  Please use this chart to observe the supernova, and
report your observations of 1836-65 SN 2001CN to AAVSO Headquarters, making
sure to indicate which comparison star(s) you used.

Congratulations to R. Chassagne on his latest discovery!


Electronic copies of the chart for SN 2001cn mentioned in this Alert Notice
are available through our web site at the following address:


It may also be obtained directly from our FTP site (


The answering machine at AAVSO Headquarters is on nights and weekends for
your convenience. Please call our charge-free number (888-802-STAR =
888-802-7827) to report your observations. We also encourage observers to
send observations by fax to 617-354-0665 or by e-mail through the Internet

Many thanks for your valuable astronomical contributions and your efforts.

Good observing!

Janet A. Mattei

Elizabeth O. Waagen
Senior Technical Assistant

AAVSO 49 Bay State Rd. Cambridge, MA 02138 617-354-0484