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AAVSO International Database

AAVSO Alert Notice 566: Beta Pic observations requested for BRITE-Constellation

January 31, 2017 : The BRIght Target Explorer-Constellation (BRITE-Constellation) satellite suite is obtaining high-precision photometry of selected very bright (mv < 4) stars. Its purpose is to investigate the "stellar structure and evolution of the brightest stars in the sky and their interaction with the local environment." The AAVSO is part of the BRITE-Constellation Ground Based Observations Team (GBOT), supporting cutting-edge science from the BRITE-Constellation satellites and coordinating with BRITE-Constellation scientist Dr.

Special Notice #428: YZ Cnc Chandra observing window delayed

January 25, 2017: The beginning of the observing window for the Chandra TOO observations of the SU
UMa-type dwarf nova YZ Cnc that are the focus of AAVSO Alert Notice 565 and AAVSO Special Notice #427 has been delayed.

Principal Investigator Dr. Christian Knigge (University of Southampton) informs us that Chandra Mission Planning has informed him that the beginning of the Chandra-observable window for YZ Cnc has been delayed until 2017 February 5.

Special Notice #427: Please continue YZ Cnc coverage for Chandra TOO observations

January 23, 2017: The observing campaign is continuing for the SU UMa-type dwarf nova YZ Cnc. In AAVSO Alert Notice 565, Dr. Christian Knigge (University of Southampton) and colleagues requested AAVSO coverage in support of Chandra X-ray observations to be carried out via a Target of Opportunity (TOO) triggering when the system was in a suitable outburst.

Alert Notice 565: YZ Cnc Chandra observing campaign

December 19, 2016: Dr. Christian Knigge (University of Southampton) and colleagues have requested AAVSO coverage of the SU UMa-type dwarf nova YZ Cnc in support of Chandra X-ray observations to be carried out via a Target of Opportunity (TOO) triggering when the system is in a suitable outburst.

YZ Cnc has normal outbursts about every 7-10 days, and superoutbursts about every 100-110 days. The astronomers are planning to use a superoutburst to trigger the TOO observations.

Special Notice #426: Blazar CTA 102 (4C 11.69) in very bright outburst

December 1, 2016: The blazar CTA 102 (4C 11.69) has been in an active state in gamma-ray and optical wavelengths since 2015. During 2016, it has had numerous flaring episodes, particularly since late October. It is presently in an unprecedentedly bright optical state, and showing substantially increased emission in gamma-ray and near-infrared wavelengths.

Alert Notice 562: Photometry of V725 Tau needed immediately

November 15, 2016: Dr. Franco Giovannelli (Istituto di Astrofisica e Planetologia Spaziali di Roma) has requested AAVSO assistance in monitoring V725 Tau, the Be star in the high-mass X-ray transient A0535+26/HDE245770, in order to plan for the X-ray outburst that follows 8 days after the optical brightening that occurs at periastron passage.

Periastron passage will occur on 16 November 2016, so coverage is needed beginning immediately and continuing for at least 15 days after periastron, until December 2.

Special Notice #425: FO Aqr XMM-Newton observations scheduled

November 9, 2016: Further to AAVSO Alert Notice 545, time series observations of the intermediate polar cataclysmic variable FO Aqr are requested to provide simultaneous coverage of XMM-Newton observations scheduled for 2016 November 13 19:43 UTC to November 14 8:13 UTC.

Alert Notice 561: Nova in Sagittarius = ASASSN-16ma = PNV J18205200-2822100

October 28, 2016

Event: Nova in Sagittarius

Discovered by:
 - ASAS-SN (K. Z. Stanek (Ohio State University) et al.; ATel #9669)
 - Yukio Sakurai (Mito, Japan; via TOCP page)

Discovery magnitude:
 - ASAS-SN: V~13.7, using quadruple 14-cm "Cassius" telescope at CTIO
 - Sakurai: 10.4 unfiltered CCD, using Nikon D7100 digital camera + 180-mm f/2.8 lens

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