GCN Circular 34744
Subject
transient AT2023sva: imaging and spectroscopic observations from MISTRAL at Observatoire de Haute-Provence
Date
2023-09-20T16:30:19Z (a year ago)
From
christophe.adami@lam.fr
Via
Web form
K. Parra-Ramos (LAM), B. Schneider (MIT), C. Adami, S. Basa (LAM), T. Adami (ENS Paris-Saclay), J. T. Palmerio, A. Saccardi, S. D. Vergani, (GEPI, Obs. de Paris), S. Antier, A. de Ugarte Postigo (OCA),
E. Le Floc'h, D. Götz, F. Schüssler, D. Turpin (CEA-Saclay), report, on behalf of a larger collaboration:
We observed the field of AT2023sva (Vail et al. GCN 34730 and de Ugarte Postigo et al. 34740) using the MISTRAL spectro-imager of Observatoire de Haute Provence (OHP) in imaging and spectroscopic (blue setting) modes.
We obtained 1x300s and 1x600s exposure in the r'-band and 2x600s on the g'-band with respective mid-epochs of 2023 09 19 01:05 UT, and 2023 09 19 01:29 UT
We derive the following photometry, calibrated against the Pan-STARRS catalog and not corrected for Galactic dust reddening:
2023 09 19 01:05 UT r' = 20.96 +/- 0.10
2023 09 19 01:29 UT g' = 21.36 +/- 0.10
We finally obtained 1h30 of exposure (3x30min) in spectroscopic mode, using the blue setting of MISTRAL. We clearly detect the continuum associated with the transient emission, leading to a redshift upper limit (z<3.5)
consistent with the redshift determination obtained by the GTC (de Ugarte Postigo et al., GCN 34740). The signal to noise in the final combined spectrum is however not sufficient to securely identify any absorption line.
We acknowledge the excellent support from Jerome Schmitt, Stephane Favard and Jean Balcaen (Observatoire de Haute Provence).