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Alert Notice 233: Rare outburst of 0837+28 EG Cancri AND Request to monitor several R Coronae Borealis stars

THE AMERICAN ASSOCIATION OF VARIABLE STAR OBSERVERS
25 Birch Street, Cambridge, MA 02138 USA
INTERNET:  aavso@aavso.org
Tel. 617-354-0484       FAX 617-354-0665

AAVSO ALERT NOTICE 233 (December 2, 1996)

RARE OUTBURST OF 0837+28 EG CANCRI

We have been informed by Patrick Schmeer, Bischmisheim, Germany, that the dwarf
nova type cataclysmic variable EG Cnc [R.A. 08h 43m 03.7s, Dec. +27o 51' 35"
(2000) is undergoing a rare, bright outburst.  The outburst was confirmed by
Tonny Vanmunster, Landen, Belgium.

Recent observations of EG Cnc reported to the AAVSO include:

Nov 21.082, <15.2, G. Poyner, Birmingham, England; 21.23, <13.7, P. Schmeer,
Bischmisheim, Germany; 30.917, 12.0, Schmeer; 30.951, 12.0, Schmeer; 30.989,
11.8, Schmeer; Dec 1.021, 12.1, T. Vanmunster, Landen, Belgium; 1.130, 11.7,
Schmeer; 1.248, 11.7, Schmeer; 2.2979, 12.0, G. Hanson, Cave Creek, AZ;
2.3326, 11.4:, T. Burrows, Novato, CA.

EG Cnc was discovered by M. Huruhata in 1983 on photographic plates showing
the star in outburst in November 1977 (IBVS No. 2401).  No subsequent outbursts
have been confirmed.  The rarity of outbursts and the substantial amplitude of
the outbursts (over 5 magnitudes) indicate that EG Cnc may be an SU UMa-type
cataclysmic variable similar to WZ Sge (McNaught, IBVS No. 2926), in which case
the present outburst would be a superoutburst.

Photometrists are urged to search for possible superhumps by observing EG Cnc
every 3-5 minutes and recording the time precisely, reporting the time to four
decimal places.

Accompanying are revised "d" and new "e" scale AAVSO preliminary charts
prepared by C. Scovil.  Please use these charts to observe EG Cnc and report
your observations to AAVSO Headquarters by telephone, fax, or email, making
sure to indicate which comparison stars you have used.

Congratulations to Patrick on his discovery of this rare outburst, and thanks
to Tonny for his prompt confirmation.

REQUEST TO MONITOR SEVERAL R CORONAE BOREALIS STARS

Our assistance has been requested by astronomers at Louisiana State University
to monitor several R CrB stars before, during, and after their observing run
at Kitt Peak National Observatory December 15 - 19, 1996.  Your observations
are very important to the success of the observing run, as they will be needed
to correlate with the observations that will be made at Kitt Peak.

Please monitor closely as many of the stars below as you can between now and
the end of December, and report your observations to AAVSO Headquarters with
your monthly report.  If you need charts for any of these stars, please let
us know.

Desig.    Name         RA + Dec (2000)

0228+55   DY Per     02h 35m 17s  +56o 08.7'
0400+53   XX Cam   04  08  39   +53  21.7
0543+19   SU Tau     05  49  06   +19  04.0
1510+83   Z UMi      15  01  31   +83  03.0
1544+28A  R CrB     15  48  35   +28  09.4
1903+17   SV Sge    19  08  11   +17  37.7
1910-33    RY Sgr     19  16  33   -33  31.3
1955+33   V482 Cyg 19  59  43   +33  58
2157-17    U Aqr       22  03  20   -16  37.7
2258+59   UV Cas     23  02  15   +59  36.7

CHARTS AVAILABLE ON AAVSO FTP SITE

Chart links are obsolete; 11/2013 create charts using VSP at http://www.aavso.org/vsp

Electronic copies of the AAVSO charts of EG Cnc mentioned in this Alert Notice
are available from our FTP site:

              ftp.aavso.org (198.116.78.2), in /pub/alert233

Due to technical difficulties, the physical sizes of the chart images do not
match precisely the "d" and "e" scales.  We hope to have the perfectly sized
charts on our FTP site tomorrow.

Also due to technical difficulties, the charts will not be accessible until
tomorrow through our Web site at the following address:

                         http://www.aavso.org

We apologize for any inconvenience caused by these technical difficulties.

The answering machine at AAVSO Headquarters is on nights and weekends for your
convenience.  Please call our charge-free number (800-642-3883) to report your
observations.  If you are cut off when you telephone in your observations,
please wait a few minutes and call back to complete your call.  We have learned
that if someone calls to leave observations on the answering machine and while
they are speaking someone else calls, the first person may be cut off.  We
also encourage observers to send observations by fax to 617-354-0665 or by
e-mail through the Internet to observations@aavso.org.  We would appreciate it
very much if you would report your observations in Universal Time.

Janet Mattei, who is away, and I thank you for your valuable astronomical
contributions and your efforts.

Good observing!

Elizabeth O. Waagen
Senior Technical Assistant

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