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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.

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 1SWASP J022916.91-395901.4, and asks if more observations (a snapshot every night through March 12, and then every one to two nights) could be made between now and March 22. V filter is optimal. Visual observations are welcome. The V range of 1SWASP J022916.91-395901.4 is 12.8-16.7.

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 targets on the list given in Alert Notice 652 (LQ Peg, UU Aqr; KQ Mon, V378 Peg, and EC 21178-5417 have already been observed). Please see that Alert Notice for information on coordinates and magnitude ranges.

Coordinates (2000) of 1SWASP J022916.91-395901.4: RA 02 29 16.95  Dec -39 59 01.7

Charts with a comparison star sequence for 1SWASP J022916.91-395901.4 may be created using the AAVSO Variable Star Plotter (VSP).

Please submit observations to the AAVSO International Database using the name 1SWASP J022916.91-395901.4.

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.

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