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AAVSO Alert Notice

Alert Notice 597: GW Lib time set for third HST observation

September 6, 2017: Further to AAVSO Alert Notices 591, 595, and 596, Dr. Boris Gaensicke (Warwick University) informs us that the date and time for the third and final of three HST observations in his campaign on the pulsating white dwarf-containing cataclysmic variable GW Lib has been scheduled for

2017 Sep 13 23:52:02 to Sep 14 04:30:12 UT.

Alert Notice 596: GW Lib time set for second HST observation

August 31, 2017: Further to AAVSO Alert Notices 591 and 595, Dr. Boris Gaensicke (Warwick University) informs us that the date and time for the second of three HST observations in his campaign on the pulsating white dwarf-containing cataclysmic variable GW Lib has been scheduled for

2017 Sep 6 22:36:04 to Sep 7 02:49:26 UT.

AAVSO Alert Notices for Observing Campaigns and Discoveries

Note: This page, together with the AAVSO Target Tool Alerts/Campaigns target list, replaces the following AAVSO webpages: AAVSO Alert Notice Archive, AAVSO Special Notice Archive, and the original Observing Campaigns webpage. - July 2017

An AAVSO Alert Notice is issued irregularly in order:

Alert Notice 595: GW Lib time scheduled for first HST observation

August 24, 2017: Further to AAVSO Alert Notice 591, Dr. Boris Gaensicke (Warwick University) informs us that the first of three HST observations in his campaign on the pulsating white dwarf-containing cataclysmic variable GW Lib has been scheduled for

2017 Aug 31 20:52:02 to 2017 Sep 1 02:12:21 UTC.

Alert Notice 594: Correction to Alert Notice 593

August 17, 2017: In AAVSO Alert Notice 593 we announced a campaign on the very long period VV Cep M2Iabe+B0/2Ve binary. The amplitude of the eclipse was wrongly given as slightly under a magnitude in the V band when it is actually around 0.1 mag. This means that the VV Cep eclipse is largely undetectable visually,  and is not a good candidate for visual observations. CCD and DSLR photometry, however, are still encouraged.

Alert Notice 593: VV Cep eclipse monitoring requested

Edit: The information given in this alert notice has been updated to correct eclipse depth values. Please see AAVSO Alert Notice 594

August 16, 2017: The AAVSO is requesting monitoring of the eclipse of the very bright Algol-type eclipsing binary variable VV Cep, predicted to have begun in June 2017 and to conclude in November 2019.

Alert Notice 592: V404 Cyg observations needed tonight for Chandra observations

August 11, 2017: Dr. Gregory Sivakoff (University of Alberta) and colleagues have requested AAVSO observers' assistance in observing the black hole X-ray transient LMXB V404 Cyg in support of Chandra observations taking place TONIGHT. The Chandra schedule is

2017 Aug 11 23:49:04.072  - 2017 Aug 12 13:42:14.730 UTC

Alert Notice 591: GW Lib observations requested in support of K2 and HST observations

August 7, 2017: Dr. Boris Gaensicke (Warwick University) has requested our help in monitoring the pulsating white dwarf-containing cataclysmic variable GW Lib in preparation for and support of K2 (Kepler's Second Light) and Hubble Space Telescope (HST) observations scheduled for August to November 2017 and August and September 2017, respectively.

K2 will be observing GW Lib non-stop 2017 Aug 23 20:00:00 to 2017 Nov 19 23:00:00 UTC.

Alert Notice 590: V1117 Her observations requested

August 7, 2017: AAVSO Young Stellar Object (YSO) Section leader Michael Poxon (Great Plumstead, Norfolk, UK) requests coverage of the YSO V1117 Her.

He writes: "The peculiar YSO V1117 Herculis has undergone a second, rapid fade and recovery only a few days after its recovery from another rapid fade. Observations, both visual and multiwavelength, are encouraged, since the behaviour of this star's historical fading episodes may indicate rapidly-changing evolution of the protoplanetary clumps in the circumstellar disc.

Alert Notice 589: R Aqr coverage needed for HST and Chandra observations

August 4, 2017: Dr. Margarita Karovska (Harvard-Smithsonian Center for Astrophysics) has requested "visual, photometric, and spectroscopic observations of the symbiotic variable R Aqr in preparation for and in support of Chandra and HST observations currently scheduled for October 2017."

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