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AAVSO International Database

Alert Notice 669: V386 Ser HST observations rescheduled

June 21, 2019: Further to AAVSO Alert Notice 667, Dr. Paula Szkody (University of Washington) informs us that the HST observations of the cataclysmic variable V386 Ser originally scheduled for last month have been rescheduled for 2019 August 1 - 3 (the exact date and time are not yet known).

It is essential to continue obtaining nightly snapshots in order to know the status of this system from now through the HST observation window.

Alert Notice 668: V1047 Cen (Nova Cen 2005) rebrightening

Note: In the original version of this Alert Notice, it was omitted that the rebrightening of V1047 Cen (Nova Cen 2005) was discovered and reported by the Gaia team as Gaia19cfn on June 10, 2019. The target was subsequently observed by OGLE. We apologize sincerely for the omission of this discovery information.  -  Elizabeth O. Waagen

Alert Notice 667: V386 Ser to be observed with HST

Updated May 24, 2019: Dr. Paula Szkody informs us that the exact time for the HST observation of V386 Ser has been scheduled for 2019 May 30 04:36-10:15 UT. This is the night of May 29/30 for US observers. Thus, the critical night will be May 28/29 (Wednesday night)  to get a measurement to HST so they can proceed to the observation. It will be essential to have positive observations from this night to satisfy the HST planners, so observers with suitable equipment are urged to obtain positive measurements of this faint star.

Alert Notice 666: CRTS J105122.8+672528 observations needed urgently

May 14, 2019: Dr. Mark Kennedy (Jodrell Bank Centre for Astrophysics, University of Manchester) is urgently requesting observations of the potential cataclysmic variable CRTS J105122.8+672528 beginning immediately. This object appears to be in outburst, having brightened to V~16.2 from its minimum magnitude of V~18.5-CV~19.

Alert Notice 665: R Aqr observations needed urgently

Note: R Aqr is out of its seasonal gap and is increasingly observable. Continued coverage is requested as described below until further notice. - Elizabeth O. Waagen, May 3, 2019

April 19, 2019:  Dr. Lee Anne Willson (Iowa State University) is urgently requesting observations of the symbiotic Mira R Aqr, particularly from our Southern observers.

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.


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