TCP J06263351-5131287 = BraTS-SON-T2-021: transient (mag. 14) in Carina

Affiliation
Association Francaise des Observateurs d'Etoiles Variables (AFOEV)
Wed, 10/07/2020 - 10:52

TCP J06263351-5131287 = BraTS-SON-T2-021 (UG:)

Discovered by the Brazilian Transient Search (BraTS) on 2020 October 3.2065 UT at mag. 13.8 CR:
http://www.cbat.eps.harvard.edu/unconf/followups/J06263351-5131287.html
https://wis-tns.weizmann.ac.il/object/2020uti

Complete 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/ac4078b6-b3ab-4684-bb81-c74ac359f5…

As already mentioned by me in a TOCP follow-up report, this transient was also recorded by the Deep Near Infrared Southern Sky Survey (DENIS) as DENIS J062633.5-513128 (Imag. 13.77, Jmag. 13.8, Kmag. 13.7; on 2000 Oct. 10.48 UT) and by ASAS-3. ASAS-3 light curve at
http://www.astrouw.edu.pl/cgi-asas/asas_variable/062634-5131.5,asas3,0,…

There were positive ASAS-3 detections (Vmag. 13–14) at the transient's position between HJD 2451868.72406 and 2451878.74269 (2000 November 20–30) as well as between 2451888.71054 and 2451908.65606 (December 10–30). The brightest magnitudes (Vmag. ~13.6–14.0, some scatter) were observed by ASAS-3 on 2000 November 20 and 21 – unfortunately exactly at the beginning of ASAS-3 coverage. Thereafter the transient faded slowly to V~14.5 on November 29, before a rapid fading to V~15.5 was observed on November 30. A sudden rebrightening / a second (super?)outburst (up to V~14.6) was observed on 2000 December 10. Thereafter the observed brightness remained almost constant for 20 days. After 2000 December 30 only negative ASAS-3 detections were reported (except for a probable outlier at V~10.4 on 2008 May 6).

Please note that the (positive) ASAS-3 detections were made at the beginning of the coverage, and that there
are some inconsistencies in the data. OTOH, the nearest potentially "contaminating" sources are almost 2' away, and the transient had already been recorded bright on 2000 October 10 by DENIS.

The light curve for October to December 2000 looks somewhat unusual for a WZ Sge-type superoutburst,
but maybe DENIS caught it on the rise, and the peak magnitude was (much) brighter than 14.

Please check your images of this sky region in Carina around RA 06h26m33.53s, DE -51°31'28.8" (J2000.0) from autumn and winter 2000.

Time-resolved photometry and spectroscopy during the current outburst are encouraged.

Clear skies,
Patrick

Affiliation
American Association of Variable Star Observers (AAVSO)
BraTS-SON-T2-021 Sequence

This Target now has a sequence

Tim Crawford, Sequence Team