SALT high resolution spectroscopy of the fading transient ASASSN-21nn
ATel #14810; D. A. H. Buckley (South African Astronomical Observatory/University of Cape Town)
on 26 Jul 2021; 12:13 UT
Credential Certification: David Buckley (dibnob@saao.ac.za)
Subjects: Optical, Transient
On 2021 July 24, beginning at 18:06:08 UTC, a 1069 s spectroscopic observation was obtained under the SALT Large Science Program on transients of ASASSN-21nn, a fading red giant reported by Rizzo Smith et al. (2021; ATel#14803). The High Resolution Spectrograph was used, covering a spectral range of 3800-8900 Å at a resolution of R = 14,000. The spectrum looks typical of a late type star, but with the addition of a shell line for Hα, with emission peaks separated by ~2 Å and a deep central absorption reversal of E.W. = 0.75 Å FWHM = 0.75 Å and with a minimum flux of ~12% of the continuum. There are no other emission or shell features seen and Hβ only appears as a narrow absorption line, similar to the absorption component seen in Hα.
Link to H-alpha spectrum plot
