Spectroscopic identification of ASASSN-15qi as an FU Ori-like object

ATel #8147; Hiroyuki Maehara (Okayama Astrophysical Observatory, NAOJ), Kazuya Ayani (Bisei Astronomical Observatory), Ryosuke Itoh, Koji Takata, Koji S. Kawabata (Hiroshima University)
on 10 Oct 2015; 00:07 UT
Credential Certification: Hiroyuki Maehara (h.maehara@oao.nao.ac.jp)

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We report spectroscopic observations of the optical transient ASASSN-15qi. This object was discovered by the All-Sky Automated Survey for Supernovae (ASAS-SN or "Assassin") at V=13.64 mag on 2015-10-03.27 and was classified as a possible YSO based on its association with an HII region (ASAS-SN Transients list; Shappee et al. 2014, ApJ, 788, 48). The object is identical to IPHAS J225608.82+583104.1 (r=16.66, i=15.59) and 2MASS J22560882+5831040 (J=13.704, H=12.923, K=12.647).

We obtained low resolution spectra of the object with the 1.01-m telescope at Bisei Astronomical Observatory, Japan (Oct 8.53; range: 400-800 nm; R=1300 at H-alpha) and the 1.5-m Kanata telescope + HOWPol at Higashi-Hiroshima Observatory, Japan (Oct 8.499; 450-900 nm; R=400). These spectra are dominated by H-alpha emission line (E.W. = -4.0 nm). H-beta and Ca II IR triplet (849.8, 854.2, and 866.2) lines are also in emission. Both H-alpha and H-beta emission lines have "P Cyg" profiles. The absorption component of H-alpha line is blue-shifted by about 500 km/s relative to the emission peak. Fe II 492.4, 501.8, Mg I 516.7 and/or Fe II 516.9, Na I D, and DIB 628.4 lines are seen in absorption. Fe II and Na I D lines are blue-shifted by about 300 km/s with respect to the rest wavelength. These features suggest that this object is likely an FU Ori- or EX Lup-like object.