Observation of Gaia22cry(AT2022nmq), candidate SN
ATel #15486; M. Dennefeld (IAP/Paris and Sorbonne University), H. Dupuis, St. Favard & J. Schmitt (OHP & OSU-Pytheas)
on 30 Jun 2022; 14:47 UT
Credential Certification: Michel Dennefeld (dennefel@iap.fr)
We observed Gaia22cry (alias AT 2022nmq, first alerted by ZTF (22aaoolua) as a SN candidate on June 25 (TNSATR 151039) and discovered independantly on June 26, 2022 by Gaia Alerts (Hodgkin et al. 2022 TNSATR 151356)) at Haute-Provence Observatory (OHP) on June 30th, 01:30 TU.
The spectro-imager MISTRAL was used at the 1.93m telescope
and the object was quite conspicuous on the r band image (r ~ 18.0).
The spectrum covered the range 405-805 nm, at a resolution of 0.2nm per pixel. The object displays a flat continuum, with strong emission lines in the red (Halpha, [NII], [SII]) at the redshift of the host galaxy UGC 169) but Hbeta and [OIII] are only marginally detected. The Balmer line ratio
(Ha/Hb ~ 7) indicates a high reddening so the intrinsic continuum could be quite blue.
There is no sign of SN features but the line ratios ([OIII]/Hb ~ 1, [NII]/Ha ~0.3 and
[SII]/Ha ~ 0.3) are reminiscent of shock excited material (embedded SN? or a SNR?). The object is worth monitoring further.
