X-ray source

Alert Notice 524: Observing campaign on 17 cataclysmic variables

July 16, 2015: Roque Ruiz-Carmona (Ph.D. candidate, Institute of Mathematics, Astrophysics and Particle Physics, Radboud University Nijmegen, The Netherlands) has requested AAVSO assistance with his campaign to observe 17 cataclysmic variables (CVs) with the William Herschel Telescope (WHT) next week.

Special Notice #9: V1343 Aql (SS433) Suzaku Observing Campaign Support

March 30, 2006: Kaori Kubota (Kyoto University) has asked for observations of V1343 Aquilae (a.k.a. SS433) in support of an observing campaign using the Suzaku X-Ray satellite. V1343 Aql is listed as an eclipsing X-Ray source according to the GCVS 3rd Edition. It consists of an early type star and a neutron star or black hole with relativistic jets detectable at X-Ray and radio wavelengths. Kubota reported it currently at 14th magnitude.

Its location is: R.A.: 19:11:49.6 Decl.: +04:58:57.9 (J2000)

Special Notice #198: Possible Outburst of GK Per

March 9, 2010: The old nova (1901) and x-ray source GK Per may be going into outburst. Reports beginning late on 2010 March 6 UT show it brightening from its minimum visual magnitude of about 13.1 to 12.3-12.4.
When GK Per went nova in 1901, its disk was destroyed. Eventually the disk was re-established, and dwarf nova-like outbursts were observed.

Special Notice #208: Optical transient in Pegasus

May 8, 2010: CBET 2273 (D.W.E. Green, editor) reports the discovery of a bright transient in Pegasus by Dae-Am Yi (Yeongwol-kun, Gangwon-do, Korea). The object was discovered at magnitude 10.8 on 2010 May 6.77 (JD 2455323.27) on an image taken with a Canon 5D + 93-mm camera lens. The object brightened to magnitude 8.4 as observed on 2010 May 7.76 (2455324.26) on an image taken with a 400-mm lens. The transient object appears to be concident with GSC 2197:886 on discovery images, but this identification is not yet proven.

Alert Notice 503: Request for regular monitoring of the symbiotic variable RT Cru

Notes:  Please continue to monitor RT Cru as it continues to decline slowly from its outburst that began in 2021 and after it returns to minimum.  -  Elizabeth O. Waagen, April 4, 2023; July 2, 2024

This campaign has been extended indefinitely. Dr. Karovska requests monitoring of RT Cru until further notice.  -  Elizabeth O. Waagen, 17 April 2020

Special Notice #383: Transient in Scorpius = TCP J17154683-3128303 [V1534 Sco]

March 27, 2014: Koichi Nishiyama (Kurume, Japan) and Fujio Kabashima (Miyaki, Japan) report (via the IAU CBAT TOCP page, http://www.cbat.eps.harvard.edu/unconf/tocp.html) their discovery of a transient in Scorpius [V1534 Sco]:
R.A. 17 15 46.83  Dec. -31 28 30.3  (2000.0)
2014 Mar. 26.84867 UT, magnitude 10.1 unfiltered CCD

Alert Notice 493: Request to monitor BP Tau in support of Chandra X-ray observations

December 18, 2013: Dr. Hans Moritz Guenther (Harvard-Smithsonian Center for Astrophysics) has requested nightly observations of the classical T Tauri star BP Tau in support of upcoming Chandra X-ray observations in his study of the accretion processes underway in this star.