AstroNote 2020-73

We draw attention to the rapidly-rising, potentially young supernovae in a nearby galaxy. The object was first discovered by ALeRCE (2020TNSTR.914....1F) in ZTF-g band images obtained on March 31, 2020 at 08:06 UT, about 3 days after the last non-detection. The object is in the TESS fields. 

The lightcurve rose by ~ 2.4 magnitudes within 1 day suggesting that this potential SN is indeed ~1 day old.

Assuming the redshift of the host (NGC 4568, z=0.007522 from NED), the SN was discovered around absolute magnitude Mg=-13.53. We triggered Swift photometry and additional observations are ongoing. The current brightness of the SN is g=16.62 mag. At the redshift of SN, this translates to a g-band luminosity of -15.9 mag.

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