We report the first radio detection of the supernova (SN) 2020tcw. This is the third hydrogen-poor SLSN detected at radio wavelengths (iPTF10hgi and SN 2017ens were detected previously, see Eftekhari et al. 2019 and ATel #14393). SN 2020tcw was discovered on 12 September 2020 (TNS Astronomical Transient Report No. 81951) and classified as a hydrogen-poor super-luminous supernova (AstroNote 2020-192). We observed SN 2020tcw 64 days post discovery with the NSF's Karl G. Jansky Very Large Array (VLA) with program VLA/20B-144 (PI: D. Matthews). We detected a radio point source within one synthesized beamwidth of the optical position. Here we report the preliminary flux density:
Name | Date (UT) | Mean Obs Freq (GHz) | Bandwidth (GHz) | Flux density (mJy) | Uncertainty (mJy) | RA | Dec
SN 2020tcw | 15 November 2020, 20:39:01 | 6.0 | 4.096 | 0.2 | 0.02 | 15:28:17.17 | +39:56:50.38
The emission at radio wavelengths may be powered by the interaction of the blastwave with a dense circumstellar environment. This scenario would be in agreement with the recent flattening (and possible rebrightening) of the optical light curves (r- and g-band) from the Zwicky Transient Facility (Kulkarni 2018; ATel #11266). Further observations are encouraged.
We thank the VLA for scheduling these observations. We are conducting further radio follow-up observations. This result is also reported in ATel #14418
Catalog | Name | Reported RA | Reported DEC | Reported Obj-Type | Reported Redshift | Host Name | Host Redshift | Remarks | TNS RA | TNS DEC | TNS Obj-Type | TNS Redshift |
---|---|---|---|---|---|---|---|---|---|---|---|---|
TNS | 2020tcw [ATLAS20zst] | 15:28:17.080 | +39:56:50.53 | SLSN-I | 0.0645 | 15:28:17.080 | +39:56:50.53 | SLSN-I | 0.0645 |
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