Spectroscopic Follow-up Observations of the symbiotic star TCP J18224935-2408280 = Gaia DR2 4089297564356878720

ATel #14699; Kenta Taguchi (Kyoto University), Hiroyuki Maehara (National Astronomical Observatory of Japan), Mitsugu Fujii (Fujii-Kurosaki Observatory), Taichi Kato (Kyoto University)
on 11 Jun 2021; 09:07 UT
Credential Certification: Hiroyuki Maehara (hiroyuki.maehara@nao.ac.jp)

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We report our spectra of TCP J18224935-2408280 = Gaia DR2 4089297564356878720 discovered by Tadashi Kojima. We obtained a low-resolution spectrum from 2021-06-07.780 UT to 2021-06-07.790 UT using the fiber-fed integral field spectrograph (KOOLS-IFU; Matsubayashi et al. 2019) mounted on the 3.8-m Seimei telescope (Kurita et al. 2020) at Okayama Observatory of Kyoto University. Also, we took two spectra on 2021-06-07.684 UT and on 2021-06-09.665 UT using the 0.4 m telescope (f/10) with a low-resolution spectrograph FBSPEC-IV at Fujii-Kurosaki Observatory.

As reported by Merc et al. (ATel #14691) and Aydi et al. (ATel #14692), our spectra show a red continuum with strong emission lines of H I, He I (4922, 5016, 5876, 6678, and 7065 Å), He II (4686 Å), and Bowen blend (around 4640 Å), and relatively weak emission lines of Fe II (5169 and 5317 Å), confirming the result that this transient is an outburst in a symbiotic star. We also identified O I lines of 7281, 7773, and 8446 Å.

In our spectrum taken by the Seimei telescope, He I lines (4922 Å and 5016 Å) are most prominent in the 4900-5050 Å range (see the second page of the PDF). The presence of strong [O III] lines is reported in the previous two ATels #14691 and #14692, however, the [O III] 4959 line cannot be seen in the spectrum. Neither is the [O III] 5007 line detected or it is very weak, because the emission component between 5000-5020 Å has its center at ∼ 5014.5 Å and is natural to be identified as He I 5016 Å. Our spectra taken at Fujii-Kurosaki Observatory also show H I, He I, He II, Bowen, O I, weak Fe II emission lines and no "strong" [O III] lines.