August 4, 2015: Dr. Gregory Sivakoff (U. of Alberta) has requested optical monitoring of the galactic microquasar V4641 Sgr beginning immediately, and continuing for the next 120 days, or until it is no longer observable from your location.
Nova Centauri 2013 -- now named V1369 Cen -- is another bright nova in our skies for 2013. Discovered by Australian observer John Seach on December 2nd, Nova Cen has now surpassed Nova Del 2013's maximum at 4th magnitude, and began a complicated evolution to (thus far) two separate maxima brighter than 3.5. Nova Cen should put on a wonderful show for southern hemisphere observers for the end of the year, and may well continue well into 2014! We'll post updates to this page as we learn more about this bright southern nova. Meanwhile, we encourage all southern hemisph
Nova Delphini 2013 (also named V339 Del) is the biggest cosmic event in variable star astronomy this year, and this naked-eye nova is providing the community a wealth of new data on this important class of objects. The amateur astronomical community has made an enormous contribution of data for Nova Del so far, and now is a good time to review all that's happened so far in this nova outburst, and how the amateur community has played a role.
October 6, 2012: The BL Lac object 4C 11.69 (== CTA 102) was discovered in bright outburst by V. Larionov, D. Blinov, and S. Jorstad (St.
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.
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:
March 30, 2011: The cataclysmic variable NSV 1436 has been discovered in outburst. This is the first bright outburst of this star observed since 1948, and followup observations are strongly encouraged. Little is known about the nature of NSV 1436, and observations may help shed light on whether the star is an infrequently outbursting normal dwarf nova, a WZ Sge star, or recurrent nova.
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).
Note: This Special Notice was originally issued as AAVSO Special Notice #231; #232 is the correct number.