AstroNote 2022-226

The Asiago Transient Classification Program (Tomasella et al. 2014, AN, 335, 841) reports the spectroscopic observations of 4 transients: AT 2022xbr, AT 2022ypb, AT 2022yvx and AT 2022sxl.

The observations were obtained on 27 October 2022 with the Asiago 1.82m Copernico Telescope equipped with AFOSC (grism4, spectral range 350-820 nm, resolution 1.4 nm).

AT 2022xbr is a normal SN Ia one week after peak. The redshift is determined from a faint narrow Halpha emission line from the host galaxy.
AT 2022ypb is a SN Ia 91T-like at maximum light.
AT 2022yvx is a Cataclysmic Variable, with a spectrum similar to that of a Dwarf Nova: The spectrum shows a weak Halpha onto a strong blue continuum. Hbeta appears as an absorption with an emission core. HeI 4471 is also in absoption and weak absorption NaD is detected. Other Balmer lines are in absorption.
The spectrum of AT 2022sxl presents relatively narrow Balmer emission lines consistent with a redshift z=0.23 on top of a blue continuum. A broad feature around 4600 A can be identified as He II 4686, or a forest of Fe II emission lines. He I 5876 is also detected. We propose the classification as a Seyfert 1 galaxy.

The classifications were performed using the GELATO (Harutyunyan et al. 2008, A&A, 488, 383) and SNID (Blondin and Tonry 2007, ApJ, 666, 1024) tools.