AstroNote 2022-188

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DRAFT
2022-09-06 20:27:41
Type: Object/s-Discovery/Classification
Likely Supernova at z > 1 in the MACS J0257.1-2325 Galaxy-Cluster Field
Authors: Patrick Kelly, Masamune Oguri, Adi Zitrin, Jose Diego, Anton Koekemoer

We have discovered a transient in the MACS J0257.1-2325 galaxy-cluster field in imaging acquired by the Hubble Space Telescope SNAP program GO-16729. In exposures taken on August 30, 2022 UT, the transient’s F105W apparent magnitude is 25.17 +- 0.28 mag, and it is not detected in the F606W with a three-sigma upper limit of 27.2 mag. We measure its coordinates to be 02:57:09.3920 -23:26:23.826 (J2000). The transient is offset from two nearby galaxies which, currently both lack a spectroscopic redshift even though MUSE spectroscopy is available. Photometric redshifts (with 95% confidence limits) from the RELICS program are 2.0-1.1+0.6 and 1.5-0.15+0.27.  Using current constraints on the lens model, a GLAFIC model finds that the supernova may be multiply imaged if it is at sufficiently high redshift (>~2), although a lack of counter images suggests itis probably not. In either case, the magnification is predicted by the GLAFIC model to be 2 or smaller. Efforts are ongoing to identify additional lens model constraints. A second visit by the GO-16729 program is scheduled for September 8, 2022 UT.

Show current TNS values
CatalogNameReported RAReported DECReported Obj-TypeReported RedshiftHost NameHost RedshiftRemarksTNS RATNS DECTNS Obj-TypeTNS Redshift
TNS2022tqq02:57:09.392-23:26:23.83SN02:57:09.392-23:26:23.83