THE AMERICAN ASSOCIATION OF VARIABLE STAR OBSERVERS 25 Birch Street, Cambridge, MA 02138 USA Tel. 617-354-0484 Fax 617-354-0665 INTERNET: aavso@aavso.org * * * AAVSO NEWS FLASH * * * Subject: SW UMa, TV Crv, CL Sco, AM Her, No. 11 ER UMa, GK Per, SY Cnc, Z Cam, April 12, 1996 YZ Cnc, AW Gem _______________________________________________________________________________ OUTBURST OF SW URSAE MAJORIS The dwarf nova cataclysmic variable (SU UMa subclass) SW UMa has gone into outburst, as the following observations indicate: UT JD Mag. Observer MAR 17.087 2450159.587 16.9 CCDV (R. Zissell, USA) MAR 18.296 2450160.796 16.2 CCDV (Zissell) MAR 19.131 2450161.631 16.1 CCDV (Zissell) MAR 31.135 2450173.635 16.4 CCDV (Zissell) APR 01.168 2450174.668 16.8 CCDV (Zissell) APR 3.145 2450176.645 16.0 CCDV (Zissell) APR 10.903 2450184.403 <14.7 (G. Poyner, England) APR 11.2278 2450184.7278 <13.9 (G. Hanson, USA) APR 11.847 2450185.347 14.0 (L. T. Jensen, Denmark) APR 11.875 2450185.375 13.5 (Jensen) APR 11.955 2450185.455 11.7 (Jensen) APR 11.969 2450185.469 11.4 (Jensen) APR 12.1125 2450185.6125 10.5 (R. Harvan, USA) The last outburst of SW UMa reported to the AAVSO International Database occurred in August 1993, when SW UMa reached visual magnitude 11.4 and was bright for approximately 9 days. Observations in this database since 1961 indicate that outbursts of SW UMa can reach as bright as visual magnitude 9.3 and can last from approximately 3 to approximately 20 days in duration. ------------------------------------------------------------------------------- BRIGHTENING OF TV CORVI We have been informed via vsnet-alert #385 that Dr. Frank Bateson, Royal Astronomical Society of New Zealand, Variable Star Section, reports that the dwarf nova type cataclysmic variable TV Crv has brightened, as the following observations indicate: UT JD Mag. Observer APR 11.4653 2450184.9653 14.5 (P. Nelson, Ellinbank, Australia) APR 11.4813 2450184.9813 14.5 (R. Stubbings, Drouin, Australia) APR 11.6132 2450185.1132 13.3 (Stubbings) APR 11.7014 2450185.2014 12.8 (Stubbings) The last confirmed outburst of TV Crv reported to the AAVSO International Database occurred in May 1994, when TV Crv reached visual magnitude 12.2 and was brighter than magnitude 15 for 13 days. ------------------------------------------------------------------------------- OUTBURST OF CL SCORPII The symbiotic variable CL Sco was reported by N. Hasegawa, Japan, in possible outburst in vsnet-alert #383 at visual magnitude 11.4 on Apr 10.72 UT. We confirm this star in outburst, as the following observation indicates: UT JD Mag. Observer APR 12.3330 2450185.8330 10.97 CCDV (W. Liller, Chile) ------------------------------------------------------------------------------- AM HERCULIS The magnetic cataclysmic variable AM Her is continuing to show activity (see AAVSO News Flash No. 7), as indicated by the following observations: UT JD Mag. Observer MAR 27.028 2450169.528 13.2 (L. T. Jensen, Denmark) MAR 27.339 2450169.839 13.50 CCDV (R. Zissell, USA) MAR 27.3743 2450169.8743 13.5 (M. Komorous, Canada) MAR 28.226 2450170.726 13.70 CCDV (Zissell) MAR 30.3243 2450172.8243 13.7 (Komorous) MAR 30.365 2450172.865 13.8 CCDV (Zissell) MAR 31.274 2450173.774 13.5 CCDV (Zissell) APR 3.205 2450176.705 13.3 CCDV (Zissell) APR 4.0639 2450177.5639 13.4 (M. Biesmans, Belgium) APR 8.0 2450181.5 13.9 (L. Szentasko, Hungary) APR 9.0090 2450182.509 13.4 (Biesmans) APR 10.983 2450184.483 13.8 (G. Poyner, England) APR 11.2429 2450184.7429 13.7:low (P. Steffey, USA) APR 11.992 2450185.492 13.4 (Jensen) Please continue to keep a close eye on AM Her and let us know its behavior. ------------------------------------------------------------------------------- ER URSAE MAJORIS The outburst of the SU UMa type cataclysmic variable ER UMa (see AAVSO News Flash No. 8) continues, as the following observations indicate: UT JD Mag. Observer MAR 29.2285 2450171.7285 12.7 (T. Burrows, USA) APR 4.2403 2450177.7403 12.7 (Burrows) APR 8.2722 2450181.7722 13.4 (Burrows) APR 8.830 2450182.33 12.9 (L. T. Jensen, Denmark) APR 10.1958 2450183.6958 13.2 (W. Dillon, USA) APR 10.3076 2450183.8076 13.0 (Burrows) APR 10.901 2450184.401 13.3 (G. Poyner, England) APR 11.2729 2450184.7729 13.1 (Burrows) APR 11.864 2450185.364 13.0 (Jensen) ------------------------------------------------------------------------------- GK PERSEI The minor outburst of the old nova GK Per (see AAVSO News Flash No. 9) continues, as the following observations indicate: UT JD Mag. Observer APR 4.1771 2450177.6771 10.7 (T. Burrows, USA) APR 5.95 2450179.45 10.6 (B. Granslo, Norway) APR 6.1813 2450179.6813 10.7 (Burrows) APR 6.8708 2450180.3708 10.7 (M. Kohl, Switzerland) APR 7.0813 2450180.5813 11.0 (R. Berg, USA) APR 7.1111 2450180.6111 10.5 (W. Dillon, USA) APR 7.1458 2450180.6458 10.7 (R. Royer, USA) APR 7.1708 2450180.6708 10.7 (Burrows) APR 7.7 2450181.2 11.0 (L. Szentasko, Hungary) APR 8.0368 2450181.5368 10.7 (M. Komorous, Canada) APR 8.0840 2450181.584 10.9 (Dillon) APR 8.1819 2450181.6819 11.2 (Berg) APR 8.824 2450182.324 11.1 (L. T. Jensen, Denmark) APR 8.8750 2450182.375 10.8 (M. Biesmans, Belgium) APR 9.1035 2450182.6035 11.0 (Dillon) APR 9.1736 2450182.6736 10.7 (Royer) APR 9.2049 2450182.7049 11.5 (G. Hanson, USA) APR 10.0944 2450183.5944 11.1 (Berg) APR 10.2604 2450183.7604 10.8 (Burrows) APR 10.857 2450184.357 11.0 (G. Poyner, England) APR 11.0279 2450184.5279 11.2 (P. Steffey, USA) APR 11.0403 2450184.5403 10.8 (Komorous) APR 11.06 2450184.56 10.9 (Granslo) APR 11.1535 2450184.6535 11.7 (Hanson) APR 12.0826 2450185.5826 11.2 (R. Harvan, USA) ------------------------------------------------------------------------------ SY CANCRI The outburst of the dwarf nova cataclysmic variable (Z Cam subclass) SY Cnc (see AAVSO News Flash No. 10) continues, as the following observations indicate: UT JD Mag. Observer APR 10.1146 2450183.6146 11.6: (T. Bretl, USA) APR 10.2944 2450183.7944 10.9 (T. Burrows, USA) APR 10.882 2450184.382 11.7 (G. Poyner, England) APR 11.2368 2450184.7368 11.0 (G. Hanson, USA) APR 11.2604 2450184.7604 11.1 (Burrows) APR 11.849 2450185.349 11.5 (L. T. Jensen, Denmark) APR 11.88 2450185.38 11.5 (G. Comello, Netherlands) ------------------------------------------------------------------------------ Z CAMELOPARDALIS The dwarf nova (prototype of its class) cataclysmic variable Z Cam is continuing to decline slowly from its recent maximum (see AAVSO News Flash No. 10), as indicated by the following observations: UT JD Mag. Observer APR 9.2396 2450182.7396 10.8 (G. Hanson, USA) APR 9.94569 2450183.4457 10.8 (M. Kohl, Switzerland) APR 10.3007 2450183.8007 10.4 (T. Burrows, USA) APR 10.904 2450184.404 10.7 (G. Poyner, England) APR 11.07 2450184.57 10.8 (B. Granslo, Norway) APR 11.2201 2450184.7201 11.2 (Hanson) APR 11.2667 2450184.7667 10.5 (Burrows) APR 11.861 2450185.361 11.0 (L. T. Jensen, Denmark) APR 11.93 2450185.43 11.2 (G. Comello, Netherlands) ------------------------------------------------------------------------------ YZ CANCRI The dwarf nova type (SU UMa subclass) cataclysmic variable YZ Cnc is declining from its recent outburst (see AAVSO News Flash No. 10), as indicated by the following observations: UT JD Mag. Observer APR 9.2368 2450182.7368 11.8 (G. Hanson, USA) APR 10.881 2450184.381 13.5 (G. Poyner, England) APR 11.1785 2450184.6785 13.1 (Hanson) APR 11.2472 2450184.7472 13.7 (T. Burrows, USA) APR 11.90 2450185.40 14.5 (G. Comello, Netherlands) ------------------------------------------------------------------------------ AW GEMINORUM The dwarf nova type cataclysmic variable AW Gem has faded from its recent outburst (see AAVSO News Flash No. 10), as the following observations indicate: UT JD Mag. Observer APR 10.1660 2450183.666 14.2: (W. Dillon, USA) APR 10.2757 2450183.7757 14.5: (T. Burrows, USA) APR 10.874 2450184.374 15.3: (G. Poyner, England) APR 11.2417 2450184.7417 <14.0 (Burrows) ------------------------------------------------------------------------------- Please monitor these stars closely and phone-in, fax, or e-mail your observations to the AAVSO. Good observing! Elizabeth O. Waagen Senior Technical Assistant for Janet A. Mattei ________________________________________________________________________________ AAVSO NEWS FLASH is a new electronic publication of the AAVSO intended to provide observers with timely information on unusual variable star activity. The basis of the data in this publication will be the observations reported to AAVSO Headquarters. The AAVSO NEWS FLASH will not replace the AAVSO Alert Notice. It will be more frequent and shorter. If you would like to contribute to AAVSO NEWS FLASH, please send observations of unusual variable star activity to: observations@aavso.org Please include the words NEWS FLASH in the subject line of your message. If you are affiliated with a variable star organization besides the AAVSO, and you wish that group to be indicated with the observations that you provide, please give the specific name of the organization or group and its abbreviation. Those who wish to unsubscribe to NEWS FLASH may do so by sending a message to: observations@aavso.org If you would like data from the AAVSO International Database for research purposes, please send your request to: Janet Mattei, AAVSO Director, at aavso@aavso.org We look forward to including your observations in future editions of AAVSO NEWS FLASH!