V544 Her: likely superoutburst, time-resolved photometry required

Affiliation
Association Francaise des Observateurs d'Etoiles Variables (AFOEV)
Mon, 04/20/2020 - 08:16

V544 Herculis (UGSU:)
https://www.aavso.org/vsx/index.php?view=detail.top&oid=15355

Gaia detection (Gaia20bus):
http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia20bus/
HERV544 20200327.179 19.06G Gaia
HERV544 20200414.625 14.93G Gaia
HERV544 20200414.699 14.90G Gaia
HERV544 20200414.876 14.91G Gaia

ZTF light curve:
https://lasair.roe.ac.uk/object/ZTF18aboacjl/

Recent ASAS-SN Sky Patrol (Shappee et al. 2014ApJ...788...48S and Kochanek et al. 2017PASP..129j4502K) light curve and data:
https://asas-sn.osu.edu/light_curves/9084f48c-2d60-4c40-9cb4-fb84b00471…
HERV544 20200401.589 <17.64g ASN
HERV544 20200417.384 14.99g ASN
HERV544 20200417.385 15.45g ASN
HERV544 20200417.386 15.30g ASN

A double (super?)outburst was observed 2018 Aug. 20–26 and Sept. 1–11 (see also T. Kato, vsnet-alert 23340). Short (= normal?) outbursts were recorded 2019 Mar. 21–22 and June 11–13.

Time-resolved photometry is urgently required.

Clear skies,
Patrick

V544 Her

Just imaged V0544 Her (at 2458962.77873) and got a CV magnitude of 18.591+/-0.005 using an ensemble from chart X25285NP.

Richard Wagner

WCR

Affiliation
Association Francaise des Observateurs d'Etoiles Variables (AFOEV)
Re: V544 Her

Thanks a lot for your report, Richard!

V544 Herculis (UGSU:)
https://www.aavso.org/vsx/index.php?view=detail.top&oid=15355

Available observations:
http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia20bus/
https://lasair.roe.ac.uk/object/ZTF18aboacjl/
https://asas-sn.osu.edu/light_curves/416c1d47-58fe-4917-9732-ccbcf8d5d3…
https://www.aavso.org/apps/webobs/results/?star=V544+Her
See also http://ooruri.kusastro.kyoto-u.ac.jp/mailarchive/vsnet-alert/24204

V544 Her was observed at mag. 15 from April 14 to 19; the rapid fading began on April 20. This long outburst
started between April 4 (ZTF) and 14 (Gaia). It was definitely *not* a normal outburst, and looks more like
a superoutburst with more than the first half missed. Time-resolved photometry was obtained only on April 19
(shortly before the rapid fading started), and only by Tonny Vanmunster (VMT).

Regards,
Patrick