THE AMERICAN ASSOCIATION OF VARIABLE STAR OBSERVERS 25 Birch Street, Cambridge, MA 02138 USA BITNET: aavso@cfa SPAN: cfa::aavso INTERNET: aavso@cfa.harvard.edu Tel. 617-354-0484 FAX 617-354-0665 AAVSO ALERT NOTICE 193 (September 29, 1994) OUTBURST OF CATACLYSMIC VARIABLE 2325+43 DX ANDROMEDAE We have been informed by Tonny Vanmunster, Landen, Belgium (Belgian Astronomical Society, VVS, Cataclysmic Variable Circular (CVC) 17), Guy Hurst, Basingstoke, England, (The Astronomer (TA) E886), and AAVSO observers in the United States that the dwarf nova type cataclysmic variable DX And is undergoing an outburst, as indicated by the following observations: Sep 23.833 UT, 12.6, T. Vanmunster, Landen, Belgium (via CVC); 23.872, 12.3, J. Pietz, Erftstadts, Germany (via CVC); 24.810, 12.2, M. Westlund, Uppsala, Sweden (via TA); 27.067, 11.7, J. Nordby, Moorhead, MN; 28.081, 11.8, R. Stewart, Rochelle Park, NJ; 28.195, 11.6, J. McKenna, Upper Montclair, NJ; 29.127, 11.6, Stewart; 29.211, 12.1, McKenna; 29.300, 12.1, Nordby; 29.375, 12.0, W. Albrecht, Pahala, HI. The most recent outbursts of this cataclysmic variable occurred in August 1993, when DX And reached magnitude 10.7 at maximum (Tonny Vanmunster was the first observer to detect the start of this outburst), and in February 1992, when it reached magnitude 11.6. The outbursts generally last two to three weeks. Please monitor the current outburst of DX And closely, using the accompanying finder chart, and report your observations to AAVSO Headquarters. 2027+52 V1974 CYGNI = NOVA CYGNI 1992 We have been informed via VSNET in Japan that Brian Skiff, Lowell Observatory, has provided faint photoelectric magnitudes for the field of N Cyg 92 = V1974 Cyg. These magnitudes are for the comparison stars marked 13.4 and 14.5 on the accompanying finder chart. The 13.4 was measured by Skiff last year at V=13.42; we have kept the magnitude at 13.4 for homogeneity of observations. The 145 extends the sequence photoelectrically. Also, early in 1994, Charles Scovil obtained a photovisual sequence by measuring the plates of V1974 Cyg; his photovisual sequence was not widely distributed at the time, but is incorporated into the accompanying chart. We welcome comments from observers as to how the 14.2 photovisual, 14.5 photoelectric, and 15.0 photovisual fit together, and also how they match the brighter end of the sequence. It is interesting and encouraging to note that Scovil obtained the same photovisual magnitude (i.e., 14.5) for the 14.5 comparison star that Skiff measured photoelectrically. Please indicate the comparison stars you used when making brightness estimates of V1974 Cyg. REQUEST TO MONITOR CATACLYSMIC VARIABLES FOR THE HUBBLE SPACE TELESCOPE (HST) AND INTERNATIONAL ULTRAVIOLET EXPLORER (IUE) A. HST Please monitor the following cataclysmic variables that will be in the observing program of HST in October: Desig Name Type Present brightness Scheduled observation 0201+14 TT Ari Dwarf nova 10.5 Oct 7 11:00 - 17:44 UT 2318+17 IP Peg Dwarf nova 11.8 - 15.3-15.8 Oct 8 13:50 - 16:20 UT 2318+17 IP Peg Oct 9 01:05 - 03:38 UT 1843+00 V603 Aql Nova 1918 11.4 Oct 12 05:00 - 11:30 UT B. IUE We have a standing request from astronomers at the VILSPA Station of the IUE in Spain to be alerted to activity in the stars described below, as they plan to observe these objects with the IUE when the circumstances are appropriate: 2138+43 SS CYGNI. Please notify us of the outburst of SS Cyg in case the outburst should be an anomalous one, that is, a symmetrical outburst in which the rise is slow. 1813+49 AM HERCULIS. Please monitor this cataclysmic variable closely whenever possible and call your observations in to AAVSO Headquarters when it begins to fade to its down state. OUTBURST OF 1439+22A UZ BOOTIS Our sincere thanks to those observers who monitored the recent rare outburst of UZ Boo. An interesting feature of the outburst was that immediately after the star faded, it briefly brightened again. Presently, we are studying the outburst behavior of UZ Boo, including this unusual behavior. Checking our database, we find that brightening right after outburst is not unprecedented for UZ Boo - there is an observation made by C. Scovil of the 1978 outburst which indicates that the star may have brightened immediately after it faded. UPDATES ON A FEW SOUTHERN R CORONAE BOREALIS TYPE VARIABLES Danie Overbeek, Edenvale, South Africa, informs us that the following Southern hemisphere R CrB stars are fading: 1834-23 V348 SAGITTARII - Aug 29.8 UT, 13.2; 30.7, 13.2; 31.7, 13.3; Sep 1.7, 13.2; 2.7, 13.2; 3.7, 13.2; 4.7, <13.4; 5.7, <13.1; 6.7, <13.4; 7.7, <13.4; 9.7, <13.4. 1428-39 V854 CENTAURI - Aug 30.7 UT, 10.2; 31.7, 10.6; Sep 1.7, 10.8; 2.7, 11.4; 3.7, 12.0; 4.7, 12.7; 5.7, 12.8; 6.7, 12.9; 7.7, <13.0; 9.7, <13.0. D. Overbeek also informs us that RZ Nor, which had been at maximum at around magnitude 11 until September 11, has also started to fade, and provides us with the following observations: Sep 11.7 UT, 11.2; 14.7, 11.8; 15.7, 12.0; 16.7, 12.3; 18.7, 12.5; 19.7, 12.7. OUTBURST OF 2209+12 RU PEGASI We have just been informed that the dwarf nova cataclysmic variable RU Peg is in outburst. Most recently, RU Peg has had two faint outbursts, one in May 1994 when it reached magnitude 11.4, and one in June 1994 when it reached magnitude 11.6. Current observations include: Sep 29.153 UT, 11.4, W. Dillon, Missouri City, TX; 29.205, 11.2, J. McKenna, Upper Montclair, NJ; 29.370, 11.8, W. Albrecht, Pahala, HI. The answering machine at Headquarters, with our charge free number (1-800-642-3883), is on nights and weekends for your convenience. Many thanks for your dedicated efforts and valuable observations. Clear skies, Janet A. Mattei Director