PNV J16271698+0405590: likely dwarf nova outburst (12.5 mag) in Hercules

Affiliation
Association Francaise des Observateurs d'Etoiles Variables (AFOEV)
Wed, 07/03/2019 - 12:19

PNV J16271698+0405590 (UG:)
https://www.aavso.org/vsx/index.php?view=detail.top&oid=838089

Discovery details:
R.A. 16h27m16.98s, Decl. +04°05'59.0" (J2000.0)
2019 July 1.9852 UT, 12.5 mag (CCD, Rc photometric filter)
Discoverer: Jan Vales (Observatorij Črni Vrh, Slovenia)

2019 07 01.9852 UT
Discovered by J. Vales at Crni Vrh Observatory on two 60-sec consecutive images, taken with the 301 mm f.l., f/4 camera lens + AP16E CCD + Rc photometric filter. There is no object at this position on similar pairs of images, obtained on 2019-06-29.986UT, 2019-06-26.992UT, 2019-06-25.939UT and 2019-06-24.978UT. MPC asteroid database give no object at this position.

2019 07 03.49 UT
The likely (blue) progenitor is USNO-A2.0 0900-08665192 (Bmag. 18.7, Rmag. 18.0) with Gaia DR2 position end figures 16.749s, 02.82" (equinox J2000.0, epoch 2015.5, Gmag. 18.83, parallax 4.4287 ± 0.3073 mas (distance 226 ± 17 pc)). Other designations are USNO-B1.0 0941-0257406, GSC2.3 N3LY010771 (Fmag. 18.52, Bjmag. 19.24, Vmag. 18.91, Nmag. 18.55), PSO J162716.756+040602.862 (gmag. 18.94, rmag. 18.82), GALEX J162716.7+040602, etc. The transient is probably a dwarf nova outburst with an amplitude of at least 6 magnitudes (WZ Sge type?). Spectroscopy as well as multiband and time-resolved photometry are strongly recommended. --- Patrick Schmeer (Saarbrücken-Bischmisheim, Germany)

http://www.cbat.eps.harvard.edu/unconf/followups/J16271698+0405590.html

Clear skies,
Patrick

Affiliation
Association Francaise des Observateurs d'Etoiles Variables (AFOEV)
ASAS-SN Sky Patrol light curve

2019 07 02.435 UT
Recent observations by the ASAS-SN Sky Patrol (Shappee et al. 2014ApJ...788...48S and Kochanek et al. 2017PASP..129j4502K) confirm this transient: 2019 June 27.251 UT, gmag. fainter than 16.14; July 2.435, 13.36; 2.436, 13.39; no previous outbursts were recorded since 2012 March 27; complete light curve at
https://asas-sn.osu.edu/light_curves/9bd03e03-bf6a-4fcf-aada-6520c59a82…
--- Patrick Schmeer (Saarbrücken-Bischmisheim, Germany)