ASKAP radio re-brightening of SN 2017hyh
ATel #17532; K. Rose (U. Sydney, CSIRO), S. Ryder (Macquarie U.), and D. Kaplan (UWM) on behalf of the VAST collaboration
on 9 Dec 2025; 05:37 UT
Credential Certification: Kovi Rose (kovirose@gmail.com)
Subjects: Radio, Supernovae, Transient
SN 2017hyh is a Type IIb SN, previously showing hints of radio re-brightening but not confirmed (Rose et al. 2024). Here we report new radio observations with the Australian SKA Pathfinder (ASKAP) showing the first confirmation of re-brightening in SN 2017hyh, with multiple events detected.
We inspected the publicly available ASKAP observations and obtained the following previously unreported Stokes I (S_I) flux densities
HTML:
| Date [UTC] |
S_I [mJy] |
Freq. [MHz] |
Len. [min] |
Survey |
| 2023 Jun 25.24 |
3.93 +/- 0.38 |
888 |
12 |
ASKAP E&C |
| 2023 Jul 5.23 |
3.82 +/- 0.40 |
888 |
12 |
VAST |
| 2023 Aug 29.97 |
4.56 +/- 0.43 |
888 |
12 |
VAST |
| 2023 Nov 1.80 |
7.30 +/- 0.61 |
888 |
12 |
VAST |
| 2023 Dec 28.73 |
7.30 +/- 0.80 |
944 |
15 |
RACS-low |
| 2023 Dec 29.73 |
6.96 +/- 0.51 |
944 |
14 |
RACS-low |
| 2024 Apr 25.36 |
5.16 +/- 0.44 |
888 |
12 |
VAST |
| 2024 Jun 21.16 |
9.40 +/- 0.67 |
888 |
12 |
VAST |
| 2024 Aug 21.99 |
10.01 +/- 0.68 |
888 |
12 |
VAST |
| 2024 Oct 31.89 |
10.18 +/- 1.83 |
1368 |
15 |
RACS-mid |
| 2024 Nov 6.87 |
6.21 +/- 0.49 |
1368 |
15 |
RACS-mid |
| 2025 Feb 16.57 |
5.27 +/- 0.44 |
888 |
12 |
VAST |
| 2025 Apr 13.37 |
6.55 +/- 0.56 |
888 |
12 |
VAST |
| 2025 Jun 9.32 |
7.43 +/- 0.53 |
888 |
12 |
VAST |
| 2025 Aug 20.11 |
8.28 +/- 0.72 |
888 |
12 |
VAST |
The uncertainties include the quadrature of the fitted error, RMS, and a 6% systematic flux scale. We consider the measurements with a signal-to-noise greater than 5 times the RMS to be significant detections.
The data used are: Rapid ASKAP Continuum Survey (RACS-low; McConnell et al. 2020, RACS-mid; Duchesne et al. 2023), ASKAP Engineering & Commissioning (Harvey-Smith et al. 2023), and Variables and Slow Transients (VAST; Murphy et al. 2021). All observations were conducted with a bandwidth of 288 MHz.
The full ASKAP lightcurve is available
here.
This work uses data obtained from Inyarrimanha Ilgari Bundara / the CSIRO's Murchison Radio-astronomy Observatory. We acknowledge the Wajarri Yamaji People as the Traditional Owners and native title holders of the Observatory site. CSIRO's ASKAP radio telescope is part of the Australia Telescope National Facility (
https://ror.org/05qajvd42 ). Operation of ASKAP is funded by the Australian Government with support from the National Collaborative Research Infrastructure Strategy. ASKAP uses the resources of the Pawsey Supercomputing Research Centre. Establishment of ASKAP, Inyarrimanha Ilgari Bundara, the CSIRO Murchison Radio-astronomy Observatory and the Pawsey Supercomputing Research Centre are initiatives of the Australian Government, with support from the Government of Western Australia and the Science and Industry Endowment Fund. Archived data can be obtained through the CSIRO ASKAP Science Data Archive,
CASDA .
