Spectroscopic and photometric observations of dwarf nova superoutbursts by the 3.8 m telescope Seimei and the Variable Star Network. (17th May 2021)

• Record Type: Journal Article
• Authors: Tampo, Yusuke; Isogai, Keisuke; Kojiguchi, Naoto; Maehara, Hiroyuki; Taguchi, Kenta; Kato, Taichi; Kimura, Mariko; Wakamatsu, Yasuyuki; Shibata, Masaaki; Nogami, Daisaku; Kawabata, Miho; Maeda, Keiichi; Namekata, Kosuke; Okamoto, Soshi; Otsuka, Masaaki; Burgaz, Umut; Nagoshi, Shumpei; Itoh, Hiroshi; Vanmunster, Tonny; Tordai, Tamás; Stone, Geoffrey; Matsumoto, Katsura; Fujii, Daiti; Matsumura, Ryota; Nakagawa, Momoka; Takeuchi, Nodoka; Zenkou, Yuki; Pavlenko, Elena P; Antonyuk, Kirill A; Pit, Nikolaj V; Antonyuk, Oksana I; Babina, Julia V; Baklanov, Aleksei V; Sosnovskij, Aleksei A; Shugarov, Sergey Yu; Katysheva, Nataly; Chochol, Drahomír; Dvorak, Shawn; Dubovsky, Pavol A; Medulka, Tomáš; Kudzej, Igor; Kiyota, Seiichiro; Zubareva, Alexandra M; Belinski, Alexandr A; Ikonnikova, Natalia P; Burlak, Marina A; Sano, Yasuo; Mizutani, Masanori; Ruiz, Javier; D. Pickard, Roger; Hambsch, Franz-Josef; Dufoer, Sjoerd; Brincat, Stephen M; Galdies, Charles; Menzies, Kenneth; Moriyama, Masayuki; Hiraga, Mitsutaka; Maeda, Yutaka; Hirosawa, Kenji; Funada, Masao; Yamamoto, Minoru;
• Is Part Of: Publications of the Astronomical Society of Japan. Volume 73:Number 3(2021)
• Page Start: 753
• Page End: 771
• Publication Date: 2021-05-17
• Subjects: accretion, accretion disks -- novae, cataclysmic variables -- stars: dwarf novae; Astronomy -- Periodicals; 520.5
• DOI: 10.1093/pasj/psab036
• Languages: English
• ISSNs: 0004-6264

Abstract

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.