Spectroscopic and photometric observations of dwarf nova superoutbursts by the 3.8 m telescope Seimei and the Variable Star Network
Abstract
We present spectroscopic and photometric observations of 17 dwarf-nova superoutbursts obtained by KOOLS-IFU mounted on the 3.8 m telescope Seimei at the Okayama Observatory of Kyoto University and through the Variable Star Network collaboration (VSNET). Our spectroscopic observations for six outbursts were performed within 1 d of their optical peak. 11 objects (TCP J00590972+3438357, ASASSN-19ado, TCP J06073081-0101501, ZTF20aavnpug, ASASSN-19ady, MASTER OT J061642.05+435617.9, TCP J20034647+1335125, ASASSN-20kv, ASASSN-20kw, MASTER OT J213908.79+161240.2, and ASASSN-20mf) were previously unknown systems, and our observations enabled quick classification of their transient type. These results illustrate that the Seimei telescope has the capability to conduct quick follow-up observations of unknown transients. Our photometric observations yielded that 11 of the objects are WZ Sge-type dwarf novae and their candidates, and the other six are SU UMa-type dwarf novae and their candidates. The He II 4686 Å emission line was clearly detected among ASASSN-19ado, TCP J06073081-0101501 and MASTER OT J213908.79+161240.2, the association of which with a spiral arm structure in an accretion disk has been suggested in previous studies. Our result suggests that a higher-inclination system shows a stronger emission line of He II 4686 Å, as well as larger-amplitude early superhumps.
- Publication:
-
Publications of the Astronomical Society of Japan
- Pub Date:
- June 2021
- DOI:
- 10.1093/pasj/psab036
- arXiv:
- arXiv:2104.04948
- Bibcode:
- 2021PASJ...73..753T
- Keywords:
-
- accretion;
- accretion disks;
- novae;
- cataclysmic variables;
- stars: dwarf novae;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 21 pages, 14 figures, 3 tables, accepted for publication in PASJ