AAVSO 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.

Dr. Mukai writes: "We think we know how dwarf novae behave in X-rays, through various campaigns (famously that one on SS Cyg in outburst that Janet Mattei [and AAVSO observers] was heavily involved in, with Pete Wheatley and Chris Mauche, 2003MNRAS.345...49W): they are X-ray bright in optical quiescence, and fainter and softer in X-rays during outburst. In the optical, we think of nova-likes as systems in permanent outburst — but in X-rays, they don’t quite resemble dwarf novae in outburst. In fact, we haven’t seen a clear pattern, when we made X-ray observations of nova-like systems at various optical magnitudes. This Chandra program is part of an effort to look for patterns and to understand their X-ray emission."

The targets in the list below will all be observed with Chandra, but to date only KQ Mon has been scheduled.

Observers are asked to obtain "a few measurements within a couple of weeks of the Chandra observations". Thus, for KQ Mon, observations from now through October 31 are requested. V filter is optimal. Visual observations are welcome.

Dr. Mukai reports that the targets are being treated as "pool targets", which means that any of them could be scheduled at short notice. Therefore, although KQ Mon is the primary target now, an occasional snapshot of the other objects would be good in order to provide ongoing context.

Name                           RA (2000) Dec (2000) Type Range

1SWASP J022916.91-395901.4 02 29 16.95 -39 59 01.7 NL/VY 12.8-16.7 V

KQ Mon                         07 31 21.13 -10 21 49.4 NL 12.5-13.7 vis

EC 21178-5417                 21 21 26.53 -54 04 34.6 NL+E 13.4-15.2 CV

LQ Peg                         21 36 19.14 +11 40 54.6 NL/VY 14.3V-17.0CV

UU Aqr                         22 09 05.70 -03 46 17.5 EA+NL: 12.85-15.5V

V378 Peg                 23 40 04.33 +30 17 47.7 NL 13.6-14.4V

Charts with comparison star sequences for each of the targets above may be created using the AAVSO Variable Star Plotter (VSP).

Please submit observations to the AAVSO International Database using the names given in the table.

AAVSO Forums: This campaign is the topic of the AAVSO Campaigns and Observation Reports forum thread https://www.aavso.org/six-novalikes-2018-campaign and the Cataclysmic Variables forum thread https://www.aavso.org/six-novalikes-2018-campaign-01

This AAVSO Alert Notice was compiled by Elizabeth O. Waagen.

AAVSO Alert Notice 651

Monitoring of T Pyx needed for HST observations

September 27, 2018: 

Dr. Ed Sion (Villanova University) requests AAVSO observers' assistance in monitoring the recurrent nova T Pyx, beginning immediately, in support of upcoming HST observations.

The HST COS observations have been scheduled to take place during the window of 2018 October 4 - 6. It is essential to know the status of T Pyx in order for the HST team to safeguard the instrumentation and make a final decision about approving the COS observations.

Beginning immediately, please observe T Pyx in V one to two times per night; V is preferred to other filters or unfiltered. Visual observations are welcome. It is particularly important to have positive observations available to the HST team from the nights of October 2/3, 3/4, 4/5, 5/6, and 6/7; they will make their decision 24 hours before the scheduled observation time. Please continue nightly V snapshots until October 15.

Please submit observations as soon after making them as possible to the AAVSO International Database. If T Pyx appears to be going into outburst, report observations immediately and email AAVSO (aavso@aavso.org). T Pyx is around magnitude 15.5 V at minimum, and can brighten to magnitude 6 in outburst. Observations brighter than 14.0-14.5 should be treated as a possible outburst beginning.

Coordinates:  R.A. 09 04 41.51   Dec.  -32 22 47.6   (2000.0)

Charts with a comparison star sequence for T Pyx may be created using the AAVSO Variable Star Plotter (VSP).

Please submit observations to the AAVSO International Database using the name T PYX.

AAVSO Forums: T Pyx is the topic of the AAVSO Campaigns and

Observations Reports forum thread https://www.aavso.org/t-pyx-monitor-hst-2018 and the AAVSO Novae forum thread https://www.aavso.org/t-pyx-monitor-hst-2018.

This AAVSO Alert Notice was compiled by Elizabeth O. Waagen.

The Z CamPaign