Alert Notice 657: HerbigAeBe stars need monitoring for Chandra observations

November 21, 2018: Dr. Hans Moritz Guenther (MIT; Kavli Institute for Astrophysics and Space Research) and colleagues have requested AAVSO observers' assistance in monitoring several HerbigAeBe stars in support of upcoming observations scheduled with Chandra.

Alert Notice 656: Chandra observation date revised for XZ Tau and HL Tau

Note: Edited November 20, 2018, to clarify the links to the forum threads for this campaign. - E. Waagen

November 7, 2018: Further to AAVSO Alert Notice 654, the date and time of the Chandra observations of the T Tauri stars XZ Tau and HL Tau scheduled for 2018 November 15 have been revised to November 11 and 12.

Dr. David Principe (MIT) informs us that Chandra is now scheduled to observe the targets on:

Alert Notice 654: XZ Tau and HL Tau monitoring needed for Chandra observations

Note: The November 15 observation with Chandra has been rescheduled to 2018 Nov. 11 17:37 - Nov. 12 00:01 UT and 2018 Nov. 12 08:01 - Nov. 12 14:27 UT. Please see AAVSO Alert Notice 656 for details. - Elizabeth O. Waagen

Alert Notice 652: Monitoring of nova-like variables in support of Chandra observations

October 11, 2018: Dr. Koji Mukai (NASA-Greenbelt Space Flight Center) has requested AAVSO assistance in monitoring several nova-like variables in support of upcoming Chandra observations. The first target, KQ Mon, is scheduled to be observed with Chandra during the week of 2018 October 15-22.

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 589: R Aqr coverage needed for HST and Chandra observations

Note: This campaign has been extended through the 2018 observing season.

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."

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.