9–13 Feb 2026
University of Canterbury
Pacific/Auckland timezone

The Eye of Sauron in SN2025ngs: A Fast Evolving Interacting Supernova with a Disc-like Circumstellar Medium

9 Feb 2026, 11:00
20m
Rātā / Engineering Core Building (University of Canterbury)

Rātā / Engineering Core Building

University of Canterbury

63 Creyke Road, Ilam, Christchurch 8041, New Zealand

Speaker

Conor Ransome (Steward Observatory, University of Arizona)

Description

Supernovae that interact with nearby circumstellar material shed by the progenitor shortly before the terminal explosion shed light on the late lives of massive stars. These objects are highly heterogeneous, with early observations shedding light on even more diversity. We present SN2025ngs, a nearby interacting supernova in NGC5961. SN2025ngs has a spectroscopic evolution almost mimicking SN1998S, with early and later interaction features. This suggests a re-emerging interaction region as the photosphere recedes. Photometrically, however, SN2025ngs is fainter, and also consistent with a short-plateau light curve. We explore the position of SN2025ngs in the landscape of interacting supernovae, and other short-plateau supernovae, and their hosts. We also present early spectroscopy, where, in high resolution data from a day post-discovery, we find evidence of a circumstellar disk around the progenitor, illustrating the complex environments of these diverse transients.

Author

Conor Ransome (Steward Observatory, University of Arizona)

Presentation materials

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