ASASSN-14cl New large-amplitude cataclysmic variable

PTS

AAVSO Special Notice #386

ASASSN-14cl New large-amplitude cataclysmic variable

June 20, 2014

Kris Z. Stanek (The Ohio State University) et al.reported the discovery during the ongoing All-Sky Automated Survey forSuperNovae

(ASAS-SN) of a bright transient (10.66V) on 2014 June14.52 UT.

Data were obtained using the quadruple 14-cm"Brutus" telescope in Haleakala, HI (hosted by Las CumbresObservatory Global Telescope Network).(ATel #6233, http://www.astronomerstelegram.org/?read=6233)

Stanek et al. also report that the object is identifiedwith SDSS

J215457.68+264112.7 (g=18.8, r=18.7), which is alsodesignated

USNO-B1.0 1166-0570046. The amplitude indicates theobject may be a WZ Sge-type cataclysmic variable.

Coordinates: R.A. 21 54 57.70  Dec. +26 41 13.0 (2000.0)

Spectroscopy by Francois Teyssier (ARAS; Rouen, France)obtained on June 15.0 UT and reported in ATel #6235

(http://www.astronomerstelegram.org/?read=6235)shows that ASASSN-14cl is a dwarf nova in outburst. Spectra may be downloadedvia the Astronomical Ring for Access to Spectroscopy (ARAS) site at http://www.astrosurf.com/aras/Aras_DataBase/Cataclysmics/_asassn-14cl_20140615_000_fteyssier.fit

Observations by Arto Oksanen (Muurame, Finland) and ColinLittlefield (South Bend, IN) show <0.1-magnitude amplitude variations, whichmay be related to early superhump formation.

Nick James (Chelmsford, England) reports a possiblesuperhump period from his observations made around June 19.0804 UT that isdifferent from earlier values published but indicates the difference may be dueto insufficient data on his part.

11 observers have contributed over 4,000 B/V/TB/TG andvisual observations to the AAVSO International Database to date. The earliestobservations reported to the AAVSO include:

2014 June 13.5 UT, <16.2 V (ASASSN);

14.91180, 10.5 visual (W. Kriebel,Schierling/Walkenstetten, Germany); 15.059, 10.6 visual (P. Schmeer,Bischmisheim, Germany); 15.18567, 10.702 V +/-0.004 (A. Oksanen, Muurame,Finland); 15.18653, 10.664 V +/-0.004 (Oksanen);

The most recent observations are:

2014 June 18.90760, 11.8 visual (Kriebel); 18.99306, 11.9visual (K. Wenzel, Grossostheim, Germany); 20.25970, 11.9 visual (M. Komorous,London, ONT, Canada);

Finder charts with a sequence may be created using theAAVSO Variable Star Plotter (http://www.aavso.org/vsp).

A new sequence has been posted for this object. Observerswho have already submitted data should check their data to see if they need tore-reduce their photometry.

Please report observations to the AAVSO InternationalDatabase using the name ASASSN-14cl.

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

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