AstroNote 2020-136

The Zwicky Transient Facility (ZTF; Bellm et al. 2019; Graham et al. 2019) Infant Supernova Science Program (Gal-Yam 2019) reports the early discovery and rapid follow-up of SN2020pni (ZTF20ablygyy), following the methodology outlined by Gal-Yam et al. (2011).

The object was first detected on ZTF r-band images obtained on July 16, 2020 at 04:44 UT, < 1 day after the last non-detection, and was picked up by our custom infant SN filter as well as the AMPEL rapid transients filter. The object was saved by a duty astronomer and rapid follow-up was triggered. The object was publicly announced by ALeRCE (2020TNSTR2150....1F) via the TNS.

The lightcurve rose by 1.8 magnitudes within ~1 day from discovery, suggesting that this SN is ~ 1-2 day old.

A SEDM (Blagorodnova et al. 2018, 2018PASP..130c5003B) spectrum was obtained ~1 day after discovery and shows narrow emissions of H and He II indicative of flash features. 

Assuming the redshift of the apparent host (UGC 9684, z=0.01687 from NED), the SN was discovered around absolute magnitude Mg=-14.46. Swift photometry has been triggered and additional observations are ongoing.

We will continue to distribute alerts on such early SN detections via AstroNotes; additional follow-up observations of this transient are encouraged.

ZTF is a project led by PI S. R. Kulkarni at Caltech, and includes IPAC; WIS, Israel; OKC, Sweden; JSI/UMd, USA; UW,USA; DESY, Germany; NRC, Taiwan; UW Milwaukee, USA and LANL USA. ZTF acknowledges the generous support of the NSF under AST MSIP Grant No 1440341. Alert distribution service provided by DIRAC@UW. Alert filtering is being undertaken by the GROWTH marshal system (Kasliwal et al. 2019), supported by NSF PIRE grant 1545949.