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AAVSO International Database

Alert Notice 664: Monitoring recurrent nova U Sco to discover its imminent eruption

April 3, 2019: Dr. Bradley E. Schaefer (Louisiana State University) provides the following information:

"Frequent monitoring is requested of the recurrent nova U Scorpii over the next year or so to discover the upcoming very-fast eruption. The predicted outburst is for the year 2020.0±0.7. The eruption is likely within the next year, but it could well go off tonight.  

"Observers of many types are needed before the next outburst:

Alert Notice 663: 1SWASP J022916.91-395901.4 being observed with Chandra

March 8, 2019: Further to AAVSO Alert Notice 652, Dr. Koji Mukai (NASA-Greenbelt Space Flight Center) informs us that 1SWASP J022916.91-395901.4, one of the novalike variables in his target list, will be observed with Chandra on 2019 March 11 22:35 UT - 2019 March 12 02:45 UT.

Alert Notice 662: V818 Sco (Sco X-1) multiwavelength campaign

February 20, 2019: Drs. Sara Motta and Jari Kajava (University of Oxford) have requested AAVSO observers' assistance in monitoring the binary X-ray source V818 Sco (Sco X-1) in support of a large multiwavelength observing campaign being carried out from now through 2019 February 24.

Alert Notice 661: Correction to AAVSO Alert Notice 659 on KQ Mon

January 28, 2019: AAVSO Alert Notice 659 announced that the nova-like variable KQ Mon will be observed with Chandra on 2019 January 29-30 UT. The exact time interval given was incorrect.

KQ Mon will be observed with Chandra on

2019 January 29 20:18 UT - January 30 00:28 UT.

A snapshot every one to two nights is requested between now and February 9. V filter is optimal. Visual observations are welcome. The visual range of KQ Mon is 12.5-13.7.

Alert Notice 660: Targets modified for LPV Maser campaign

January 25, 2019: Further to AAVSO Alert Notice 645, Michael Stroh (Ph.D. candidate, University of New Mexico) informs us that two of the VLA targets on his list of 19 long period variables for his SiO maser study that is underway have been removed and two other targets added.

The stars removed from the campaign are V1301 Cyg and V1659 Cyg. The stars taking their places are V657 Cas and V850 Cas. Below is a revised list of the targets for this campaign.

Alert Notice 659: KQ Mon being observed with Chandra

Note: The time of the Chandra observation was incorrect in the original version of this Alert Notice. The text below has been edited so that the time is correct. This correction was announced in AAVSO Alert Notice 661. - Elizabeth Waagen

Alert Notice 658: EC 21178-5417 being observed with Chandra

December 3, 2018: Further to AAVSO Alert Notice 652, Dr. Koji Mukai (NASA-Greenbelt Space Flight Center) informs us that EC 21178-5417, one of the novalike variables in his target list, will be observed with Chandra on 2018 December 5 20:18 UT - December 6 01:00 UT.

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 655: Anticipated secondary eclipse of b Persei by its third star in November 2018

Note: Text revised October 30 to include date and time on which the predicted eclipse window is centered. It was further revised November 2 to correct the SAO number of b Per and to correct the position of the check star. - E. O. Waagen

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