Radio brightening of TDE 2025aarm in ASKAP data

ATel #18150; Andrea Simongini (INAF-OAR, UniRoma2), Alice Nucara (INAF-IAPS, UniRoma2), Maria Kherlakian (RUB)
on 10 Nov 2026; 20:29 UT
Credential Certification: Andrea Simongini (andrea.simongini@inaf.it)

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We report radio detection and flux evolution of the nearby TDE 2025aarm (z = 0.01368) obtained as part of the Australian SKA Pathfinder (ASKAP) Variables and Slow Transients survey (Murphy et al. 2013, PASA, 30, 6). We inspected the publicly available ASKAP observations and obtained previously unreported Stokes I flux densities at 0.887 GHz.

Observations between September 29, 2025, and March 10, 2026, do not show any significant excess above the rms level (0.3 mJy) of each map. The first detection above the 3 sigma level was achieved on April 10, 2026, with a preliminary flux density of 1 mJy. In the following months the flux has increased almost linearly, reaching a level of 4.5 mJy on August 27, 2026. Assuming a distance of 61.5 Mpc (Simongini et al. 2026, A&A, 710, L34) this corresponds to a luminosity of 2e+28 erg/s/Hz.

TDE 2025aarm was previously detected with the Very Large Array on November 4, 2025, at 15.1 GHz with a flux density of 36 +/- 10 microJy (Christy et al. 2025, AstroNote 2025-315).

We encourage further multi-wavelength observations of this source.

ASKAP data are obtained from Inyarrimanha Ilgari Bundara, the CSIRO 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.

The full ASKAP lightcurve is available here