AstroNote 2021-212

We continue our search of supernovae (SNe) in mid-infrared using the recent release of NEOWISE-R 2021, which ranges from December 13, 2019 to December 13, 2020 UTC. Details about our search method in Thévenot et al. 2021 (2021RNAAS...5...58T).

We search classified SNe for this timescale and find 100 SNe with mid-IR detections, which are listed in the attached CSV table.

We find the notable mid-IR detections:
-The SLSN-II 2020edi (ZTF20aasuiks) shows a record brightness for mid-IR detections of SNe. It reaches an absolute W1 (AbsW1) magnitude of -26.5 at 109.7 days after the discovery. We do not find any pre-discovery activity of the galaxy nucleus in the NEOWISE-R single exposure table. The SNe 2020iq and 2020usa are also very bright in mid-IR, but still about 2.5 magnitudes fainter than 2020edi.
-We note that the type Ia SNe 2020aaym, 2020yex and 2020eyj show AbsW1 consistent with type Ia-CSM. 2020eyj has already described CSM interaction (Fremling et al. 2021 2021arXiv210412980F).
-The type Ib SN 2020hvp shows a very red (W1-W2=1.85 mag) color.
-SNe from our list without previous multi-epoch detection were searched in NEOWISE for long-lasting mid-IR detections. SN 2019jys (type IIn) and SN 2019vxm (type II) show mid-IR light curves that are reminiscent of 2010jl-like SNe.

This publication makes use of data products from the Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE), which is a joint project of the Jet Propulsion Laboratory/California Institute of Technology and the University of Arizona. NEOWISE is funded by the National Aeronautics and Space Administration.