A long look at V3890 Sgr during its SSS phase with the AstroSat SXT
ATel #13145; K. P. Singh (IISER, Mohali), V. Girish (ISRO Hq, Bengaluru), G. C. Anupama (IIA, Bengaluru), M. Pavana (IIA, Bengaluru)
on 29 Sep 2019; 15:56 UT
Credential Certification: G.C. Anupama (gca@iiap.res.in)
We carried out a long, continuous observations of the symbiotic recurrent nova V3890 Sgr from 2019 September 12 18:45 UT (~ day 16) to September 16 07:14 UT (~ day 19.5) with the AstroSat Soft X-ray Telescope (SXT), getting a useful exposure time of 66 ksec. The highly variable or flaring phase had not only continued, but had further intensified with the flares reaching 5 times the intensity of the lowest intensity observed, and as seen with the Swift-XRT (ATel#13104). The strong and rapid (at least 3 flares in a day) flaring activity lasted until 2019 September 14 (~ day 17), after which the intensity declined considerably and was quite steady for a day at a low level similar to that seen earlier (ATel#13102). The intensity picked up again on 2019 September 15, but remained almost steady at twice the intensity level until the end of our observations, with only one flare recorded. All the variability continued to be in the soft black-body as reported earlier (ATel#13102, ATel#13104, ATel#13124). Our observations confirm that the super soft state of the source was continuing during these days.
The data are being analysed to study the X-ray spectral evolution over these four days.
We thank the ISSDC, Bengaluru for scheduling these observations at a short notice. We thank the SXT Payload Operation Centre (POC) at TIFR for quick pipeline processing and providing the level2 data.
