Alert Notice 671: LQ Peg being observed with Chandra

July 12, 2019

AAVSO Forums: This campaign is the topic of the AAVSO Campaigns and Observation Reports forum thread
and the Cataclysmic Variables forum thread

Further to AAVSO Alert Notice 652, Dr. Koji Mukai (NASA-Greenbelt Space Flight Center) informs us that LQ Peg, one of the novalike variables in his target list, will be observed with Chandra on 2019 July 19 13:09 UT - 17:30 UT.

Knowing the status of the target is essential for interpreting the X-ray data. Dr. Mukai thanks observers for the observations they have already made of LQ Peg, and asks if more observations (a snapshot every night through July 20, and then every one to two nights) could be made between now and July 30. V filter is optimal. Visual observations are welcome. The CV range of LQ Peg is 14.3 - 17.0 CV.

As Dr. Mukai wrote in Alert Notice 652, "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."

Observers are reminded that occasional snapshots (again, V is preferred) are also needed of the remaining target on the list given in Alert Notice 652 (UU Aqr; KQ Mon, V378 Peg, EC 21178-5417, and 1SWASP J022916.91-395901.4 have already been observed). Please see that Alert Notice for information on coordinates and magnitude range for UU Aqr.

Coordinates (2000) of LQ Peg: RA 21 36 19.14  Dec +11 40 54.6

Charts with comparison star sequences for LQ Peg may be created using the AAVSO Variable Star Plotter (VSP).

Please submit observations to the AAVSO International Database using the name LQ PEG.

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


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