THE AMERICAN ASSOCIATION OF VARIABLE STAR OBSERVERS 25 Birch Street, Cambridge, MA 02138 USA Tel. 617-354-0484 Fax 617-354-0665 http://www.aavso.org * * * AAVSO NEWS FLASH * * * Subject: 2138+43 SS CYG 1911-00 FO AQL No. 642 0854-24 VZ PYX 1953+77 AB DRA July 10, 2000 1552+72 SS UMI ---------------------------------------------------------------------------- 2138+43 SS CYGNI CAMPAIGN AND NOTE OF THANKS: SINCEREST THANKS to all our observers who have been observing SS Cygni very closely and sending their observations to us regularly. Thanks to your efforts and observations we have been alerted to the brightening of SS Cyg immediately, and once it was certain that SS Cyg was definitely in outburst, last night proposals were submitted for the Target of Opportunity (ToO) observations with the three satellites - Chandra x-ray satellite, RXTE, and EUVE. (9-1-00 UPDATE - A second target of opportunity window has been approved for September! Please observe through the next outburst and report activity as soon as possible.) (9-13 UPDATE - The campaign was successful and both Chandra and EUVE are observing the satellite. Please continue making careful observations until the end of the outburst.) This morning we were informed that unfortunately due to problems with the High Energy grating of Chandra, the ToO observations with that satellite can not be scheduled at this time. Since Chandra is the primary satellite for the ToO observations of SS Cyg, the other satellite (RXTE and EUVE) observations have been cancelled at this time also. There is a possibility that Chandra observations, along with RXTE and EUVE ones may be scheduled in early part of next week, if SS Cyg is still at maximum at that time. Thus, at this time we send a plea to all of you our observers again, please keep a close eye on SS Cyg during its current outburst, and continue to send in your observations nightly to determine the duration of this outburst. Good news -- a few months ago, astronomers at the University of Florida, Jet Propulsion Laboratory and Planetary Science Institute requested us to inform them of the start of the July outburst of SS Cygni so that the "First-Ever infrared Interferometric observations of a cataclysmic variable [SS Cygni]" can be carried out with the Palomar Testbed Interferometer to directly measure the size of a cataclysmic variable. This is truly a pioneering research in CVs! Last night we informed our colleagues of the start of SS Cyg outburst so that this "first-ever" interferometric observations can be scheduled. They are on the target at this time! Again, on behalf of our colleagues, and personally many, many thanks to you our observers for your dedication and observations! My personal thanks also to our technical staff, Kerri Malatesta, Gamze Menali, Rebecca Pellock, and Elizabeth Waagen, who have been working very hard in compiling all the nightly observations on SS Cyg, and in my absence, regularly informing our colleagues of its behavior! Since mid-June I had been teaching about variable stars and AAVSO's Hands-On Astrophyicss to an excellent group of teachers and students at TOPS 2000 workshop (http://www.ifa.hawaii.edu/tops/). We now have a new, very enthusiastic group of variable star observers from Texas, Hawaii, and the Pacific Islands, joining us! --- JAM----- Below are observations of SS Cyg submitted to the AAVSO showing its most recent, anticipated outburst: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials JUL 03.923 11.8 TUB JUL 09.1674 11.1 SXN JUL 06.2229 12.0 DIL JUL 09.1694 11.3 MDP JUL 06.854 11.9 TUB JUL 09.1823 11.4 PAH JUL 07.338 11.9 MRV JUL 09.2070 11.12 CCDV ZRE JUL 07.97 11.6 GUN JUL 09.2222 10.9 LNZ JUL 07.986 11.7 MUY JUL 09.2278 11.2 RR JUL 08.003 12.0 OJR JUL 09.2542 11.2 BTH JUL 08.1065 11.4 CGF JUL 09.3500 10.9 LMK JUL 08.1215 11.8 BRJ JUL 09.4354 10.9 HSG JUL 08.1653 11.7 MKJ JUL 09.5389 10.5 LMK JUL 08.1730 11.80 CCDV ZRE JUL 09.5937 10.2 LMK JUL 08.1771 12.0 KB JUL 09.843 9.2 TUB JUL 08.2229 11.9 RR JUL 09.8528 9.6 BSR JUL 08.2930 11.65 CCDV ZRE JUL 09.8535 9.6 FSE JUL 08.3438 11.5 PCH JUL 09.8549 9.5 FSE JUL 08.3510 11.54 CCDV ZRE JUL 09.8590 9.3 BSR JUL 08.3764 11.9 CKN JUL 09.8611 9.4 FSE JUL 08.3868 11.2 LMK JUL 09.8660 9.5 FSE JUL 08.8785 11.4 FSE JUL 09.8701 9.4 FSE JUL 08.8806 11.4 FSE JUL 09.8771 9.2 FSE JUL 08.8938 11.2 FSE JUL 09.8781 9.43 CCDV FGI JUL 08.9021 11.1 FSE JUL 09.8847 9.1 FSE JUL 08.9049 11.1 FSE JUL 09.8919 9.41 CCDV FGI JUL 08.9076 11.1 FSE JUL 09.8965 8.9 FSE JUL 08.9181 11.1 FSE JUL 09.9076 8.8 FSE JUL 08.92 11.1 VET JUL 09.9095 9.40 CCDV FGI JUL 08.9215 11.0 FSE JUL 09.910 9.3 RMQ JUL 08.9368 11.0 FSE JUL 09.9105 9.37 CCDV FGI JUL 08.938 11.2 RMQ JUL 09.9194 8.7 FSE JUL 08.9424 11.1 FSE JUL 09.9285 8.6 FSE JUL 08.9472 11.2 FSE JUL 09.938 8.9 RMQ JUL 08.9486 11.1 FSE JUL 09.9410 8.7 FSE JUL 08.9542 11.0 FSE JUL 09.9444 8.6 FSE JUL 08.9583 11.1 FSE JUL 09.9507 8.6 FSE JUL 08.9604 11.1 FSE JUL 09.9556 8.7 FSE JUL 08.9639 11.2 FSE JUL 09.9646 8.7 FSE JUL 09.017 11.6 OJR JUL 09.9736 8.6 FSE JUL 09.0781 11.2 PAH JUL 10.0778 8.8 SET JUL 09.0816 11.7 PAH JUL 10.1743 8.5 KB JUL 09.0944 11.3 MDP JUL 10.2049 8.8 DIL JUL 09.0951 11.2 KMA JUL 10.2139 8.5 BTH JUL 09.1153 11.4 MDP JUL 10.2333 8.9 RR JUL 09.1243 11.7 BRJ JUL 10.2500 8.4 SXN JUL 09.1458 11.2 MDP JUL 10.3653 8.3 SXN JUL 09.1580 11.13 CCDV ZRE JUL 10.4577 8.9: DEH JUL 09.1604 11.3 MDP ---------------------------------------------------------------------------- 0854-24 VZ PYXIDIS The dwarf nova type (SU UMA subclass) cataclysmic variable VZ PYX may be in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials JUN 19.4514 14.0 PEX JUL 08.3486 12.8 WPX ---------------------------------------------------------------------------- 1552+72 SS URSAE MINORIS The dwarf nova type (SU UMA subclass) cataclysmic variable SS UMI is in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials JUL 07.2132 <15.8 HSG JUL 08.922 <14.2 OJR JUL 07.911 <14.2 OJR JUL 09.1264 14.6 BRJ JUL 07.952 <14.2 MUY JUL 09.4229 14.4 HSG JUL 08.12 <14.7 BRJ JUL 09.933 14.8 RMQ ---------------------------------------------------------------------------- 1911-00 FO AQUILAE The dwarf nova type (SS CYG subclass) cataclysmic variable FO AQL is in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials JUL 06.282 16.4 CCDV OCN JUL 08.476 14.7 SRX JUL 07.2021 <13.9 SXN JUL 08.683 14.0 SRX JUL 07.2326 <14.5 HSG JUL 08.92 14.2 VET JUL 07.978 <13.9 MUY JUL 09.001 <14.5 OJR JUL 08.017 <14.5 OJR JUL 09.1188 14.4 BRJ JUL 08.12 <14.5 BRJ JUL 09.4174 13.9 HSG JUL 08.1778 <13.9 MKJ JUL 09.922 14.1 RMQ JUL 08.476 14.7 SRX JUL 10.2701 13.9 SXN ---------------------------------------------------------------------------- 1953+77 AB DRACONIS The dwarf nova type (Z CAM subclass) cataclysmic variable AB DRA is in outburst, as indicated by the following observations: AAVSO Observer AAVSO Observer UT Mag. Initials UT Mag. Initials JUL 06.1 <14.0 CGF JUL 08.1243 12.6 BRJ JUL 06.1833 14.2 HSG JUL 08.93 12.2 PUJ JUL 07.1590 13.7 CGF JUL 08.945 12.6 RMQ JUL 07.1861 13.5 HSG JUL 08.965 12.7 OJR JUL 07.2118 13.4 HSG JUL 09.1278 12.5 BRJ JUL 07.2354 13.5 HSG JUL 09.33 12.4 LMK JUL 07.9292 13.0 JCN JUL 09.340 12.5 LMK JUL 07.955 12.9 MUY JUL 09.4208 12.7 HSG JUL 08.033 12.7 OJR JUL 09.908 12.7 RMQ ---------------------------------------------------------------------------- We thank the following contributors for the data that they have provided for this News Flash: BRJ - J. BORTLE, USA MRV - R. MODIC, USA BSR - S. BARONI, ITALY MUY - E. MUYLLAERT, BELGIUM BTH - T. BURROWS, USA OCN - S. O'CONNOR, CANADA CGF - G. CHAPLE JR., USA OJR - J. OSORIO, SPAIN CKN - K. CASTLE, USA PAH - C. PRICE, USA DEH - E. DONAGHY, USA PCH - C. PULLEN, USA DIL - W. DILLON, USA PEX - A. PEARCE, AUSTRALIA FGI - G. FAVERO, ITALY PUJ - F. PUJOL, SPAIN FSE - S. FOGLIA, ITALY RMQ - M. RESZELSKI, POLAND GUN - J. GUNTHER, FRANCE RR - R. ROYER, USA HSG - G. HANSON II, USA SET - C. STEPHAN, USA JCN - C. JONES, ENGLAND SRX - R. STUBBINGS, AUSTRALIA KB - W. KAMINSKI, USA SXN - M. SIMONSEN, USA KMA - M. KOMOROUS, CANADA TUB - V. TUBOLY, HUNGARY LMK - M. LINNOLT, USA VET - M. VERDENET, FRANCE LNZ - G. LENZ, USA WPX - P. WILLIAMS, NEW ZEALAND MDP - P. MCDONALD, CANADA ZRE - R. ZISSELL, USA MKJ - J. MCKENNA, USA Please monitor these and other variable stars closely and phone-in, fax, or e-mail your observations to the AAVSO. Good observing! Janet A. Mattei, Director Kerri Malatesta, Technical Assistant ____________________________________________________________________________ Symbols may include: < = fainter than magnitude given (variable not seen) : = uncertain CCDV = Charge-coupled device with (V) filter If you would like to contribute to AAVSO NEWS FLASH, please send observations of unusual variable star activity to: observations@aavso.org Those who wish to subscribe (free of charge) or unsubscribe to NEWS FLASH may do so by visiting the following web page: http://www.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 An archive of past issues of the News Flash is available at the following web page: http://www.aavso.org/newsflash/ We look forward to including your observations in future editions of AAVSO NEWS FLASH! ____________________________________________________________________________