cataclysmic variables

Alert Notice 345: Request to monitor cataclysmic variables for radio observations

February 15, 2007: Dr. Christian Knigge, University of Southampton, England, has requested our assistance in monitoring ten (10) dwarf novae cataclysmic variables as part of a search for radio jet formation during outbursts. Dr. Knigge is attempting to observe a dwarf nova outburst within six hours of the outburst onset using the NRAO Very Large Array (VLA) telescope in New Mexico and the Jodrell Bank MERLIN telescope in the United Kingdom.

AAVSO observers help solve a mystery about an important variable star

A group of astronomers led by Dr. James Miller-Jones of Curtin University and the International Centre for Radio Astronomy Research have published a revised distance to the famed variable star SS Cygni, solving a major mystery surrounding this star and its behavior.  Their work was made possible due to the dedication of dozens of observers worldwide who monitor SS Cygni and report their observations to the American Association of Variable Star Observers (AAVSO).

Special Notice #265: Bright Symbiotics in Sgr, Cyg, and Oph

March 3, 2012: Observer S. O'Connor reported late last week that the symbiotic stars V4018 Sgr, CH Cyg, and V2523 Oph all appeared to be in outburst or brighter than normal.  He reports: V4018 Sgr at V=11.59 on JD 2455981.021 (2012 Feb 23.521); CH Cyg at V=7.30 on 2455982.976 (Feb 25.476); and V2523 Oph at V=11.67 on 2455981.0 (Feb 23.5).  Other more recent visual observations of CH Cyg by G. Holmberg (vis=7.6 on 2455983.4993) and D. Barrett (vis=7.4 on 2455985.6013) confirm the star is well above magnitude 8.0 at this time.

New results on FS Aurigae

The paper "Optical and X-ray Variability of the Peculiar Cataclysmic Variable FS Aurigae with a Magnetic and Freely Precessing White Dwarf" by Vitaly Neustroev and collaborators is now available on arXiv.org.  The paper was co-authored by several AAVSO observers, and involves data taken during the 2010-2011 observing campaign.

Special Notice #261: Outburst of the UGWZ Candidate BW Scl

October 21, 2011: The short period cataclysmic variable BW Scl appears to be in outburst. The object was detected in outburst at m(vis)=9.6 by M. Linnolt on 2011 October 21.3146 (JD 2455855.8146), and confirmed by A. Plummer at m(vis)=9.4 on October 21.3424.  Observations of this object are encouraged.  The object has conflicting classifications in astronomical literature, but is probably a WZ Sge-type dwarf nova rather than a novalike variable.

BW Scl is located at the following (J2000) coordinates:

Alerta de AAVSO 436

Erupción de la nova recurrente T Pyxidis
14 de abril de 2011

La nova recurrente T Pyxidis ha sido descubierta en erupción. Fue detectada por M. Linnolt (Hawaii, Estados Unidos) con magnitud visual 13.0 en abril 14.2931, 2011 (JD 2455665.7931), y confirmada por A. Plummer (m(vis)=12.2, JD 2455665.8847) y S. Kerr (m(vis)=11.3, JD 2455665.9410).  Esta es la primer erupción de T Pyx desde el 7 de diciembre de 1966, hace casi 45 años. Se solicitan urgentemente observaciones de esta rara variable eruptiva, comenzando inmediatamente.

Special Notice #233: Bright outburst of the cataclysmic variable SDSS J133941.11+484727.5

February 7, 2011: The star SDSS J133941.11+484727.5 has been reported in outburst by Jeremy Shears (Bunbury, UK).  Shears reports this star at magnitude 10.4 on 2011 February 7.919 (JD 2455600.419).  This is approximately 7 magnitudes above quiescence, which suggests a superoutburst of an SU UMa star or a WZ Sge-like outburst.  Gary Poyner (Birmingham, UK) confirms this outburst, estimating the star at 10.5 on February 7.959 (2455600.459).