News and Announcements
|25 July||Special Notice #291: Brightening of LBV HDE 269006 = R71||
July 26, 2012: The luminous blue variable (LBV) HDE 269006 = R71 in the Large Magellanic Cloud is brightening and is currently at V magnitude 8.3.
Observations in the AAVSO International Database going back to 1987 show HDE 269006 at visual magnitude ~10.8 until 2006, when it began to brighten, reaching magnitude ~8.5 in late 2009. It then declined to ~magnitude 9 by late 2012, where it has been since then.
|24 July||Special Notice #290: Blazar BL Lac bright||
July 24, 2012: The blazar BL Lac, the prototype of this class of variable objects, has brightened in the optical and radio wavelengths. ATel #4271 (Sh. A. Ehgamberdiev et al., http://www.astronomerstelegram.org/?read=4271) on July 23 announced this brightening. The ATel team reported that "the source brightness has recently increased from R = 13.66 +/- 0.01 on July 19.82 to R = 12.60 +/- 0.01 on July 22.97.
|20 July||Alert Notice 465: Nova Sagittarii 2012 No. 5 = PSN J18193700-1907400||
July 20, 2012
|13 July||AAVSO Newsletter 53 is now online||
AAVSO Newsletter 53, July 2012, is now online.
|12 July||Solar Bulletin - Volume 68, Number 6||
The June 2012 Solar Bulletin is now available!
|11 July||New eJAAVSO preprint: "A Century of Supernovae"||
(ej207): "A Century of Supernovae" by P. Garnavich
|07 July||Special Notice #289: Bright possible nova in Sagittarius = PNV J18202726-2744263||
July 7, 2012: A new, bright (V and unfiltered magnitudes 7-8) object has been independently discovered in Sagittarius by at least four observers. The IAU CBAT TOCP page identifies the object as PNV J18202726-2744263 and gives the earliest report (Koichi Nishiyama and Fujio Kabashima) date and time of 2012 July 07.4986 UT and their magnitude 7.8 unfiltered CCD.
|06 July||Alert Notice 464: Observers requested for Jovian Extinction Events (JEE2012)||
July 5, 2012: Scotty Degenhardt (Santa Fe, NM), a pioneer in the use of video for timing eclipses of solar system and stellar objects and a research member of the International Occultation Timing Association (IOTA), has informed the AAVSO of a research project he and colleagues are working on: modeling the Jovian dust field, moon atmospheres, and Io’s Torus through Jovian Extinction Events (JEE). He has invited AAVSO observers to participate by observing these Jovian extinction events and reporting their observations.
|03 July||Alert Notice 463: Nova Sagittarii 2012 No. 3 = PNV J17522579-2126215||
July 3, 2012:
|29 June||New eJAAVSO preprint: "Classical and Recurrent Novae" by U. Munari||
(ej206): "Classical and Recurrent Novae" by U. Munari
|28 June||Special Notice #288: Supernova 2012db in ESO 139-G28 = PSN J17484870-6042193||
June 28, 2012: IAU Central Bureau Electronic Telegram 3155 (Daniel W. E. Green, ed.) announces the discovery (reported by A. Klotz on behalf of the TAROT collaboration) of a supernova in ESO 139-G28 on 2012 June 24.27 UT at R magnitude 14.6 +/- 0.1, using public images of the 0.25-m TAROT robotic telescope at La Silla, Chile.
|28 June||Special Notice #287: Request to observe X-ray transient Swift J1910.2-0546||
June 28, 2012: The recently discovered gamma-ray source Swift J1910.2-0546 (Krimm et al., ATel #4139; Barthelmy et al., GCNC #13369; T. Ohshima., vsnet-alert 14674) is optically bright, reaching magnitude CR = 15.7 on 2012 June 14 (R. Pickard, BAAVSS, using the Faulkes Telescope South). The object was also observed by A. Odasso, using the Sierra Stars Observatory Network (A.
|28 June||New eJAAVSO preprint: "28 years of CV results with the AAVSO" by P. Szkody et al.||
(ej205): "Twenty-Eight Years of CV Results With the AAVSO"
|27 June||Two new eJAAVSO preprints: EBs in the 21st century; Transiting Exoplanets||
(ej203): "Eclipsing Binaries in the 21st Century—Opportunities for Amateur Astronomers" by E. F. Guinan, S. G. Engle, E. J. Devinney
(ej204): "How Amateurs Can Contribute to the Field of Transiting Exoplanets" by B. Croll
|25 June||Alert Notice 462: Monitoring of J1407 for next extrasolar ring system transit||
June 25, 2012: Dr. Eric Mamajek (Cerro Tololo Interamerican Observatory and University of Rochester) has requested AAVSO observers' assistance in monitoring the young star 1SWASP J140747.93-394542.6 to help determine the eclipse behavior related to a transiting ringed substellar companion.
|22 June||New eJAAVSO preprint: Amateur Observing Patterns and Their Potential Impact on Variable Star Science||
(ej202): "Amateur Observing Patterns and Their Potential Impact on Variable Star Science" by M. R. Templeton
|20 June||New eJAAVSO preprint: "What Are the RCB Stars?"||
(ej201): "What Are the R Coronae Borealis Stars?" by G. C. Clayton
|19 June||New eJAAVSO preprint: on AAVSO IT Infrastructure 1967-1997||
(ej200): "An Overview of the AAVSO’s Information Technology Infrastructure From 1967 to 1997" by R. C. S. Kinne
|19 June||Three new eJAAVSO preprints||
(ej199): "Long-Term Visual Light Curves and the Role of Visual Observations in Modern Astrophysics" by J. R. Percy
(ej198): "A Study of the Orbital Periods of Deeply Eclipsing SW Sextantis Stars" by D. Boyd
(ej197): "The AAVSO Widow—Or Should We Say Spouse?" by T. R. Williams
|15 June||New eJAAVSO preprint: RS Sge: The Search for Eclipses||
(ej196): "RS Sge: The Search for Eclipses" by J. D. Horne
|15 June||Solar Bulletin - Volume 68, Number 5||
The May 2012 Solar Bulletin is now available!
|14 June||APASS DR6 Press Conference Video|
|14 June||Skin a Cat - Looking for period change in data|
|13 June||New eJAAVSO preprint: on pulsation, dust production, and mass-loss||
(ej195): "Variable Stars and the Asymptotic Giant Branch: Stellar Pulsations, Dust Production, and Mass Loss" by A. K. Speck
|12 June||New eJAAVSO preprint: Centennial highlights in astronomy||
(ej194): "Centennial Highlights in Astronomy" by O. Gingerich