26–29 May 2026
Radisson Blu Marina Palace Hotel
Europe/Helsinki timezone

Characterisation of Type Ibn SNe using Zwicky Transient Facility data

28 May 2026, 16:45
15m
Room C

Room C

Speaker

Anjasha Gangopadhyay (Oskar Klein Centre, Stockholm University, Sweden)

Description

We present the photometric analysis of 39 Type Ibn supernovae discovered by the Zwicky Transient Facility (ZTF). While the majority of events exhibit the canonical fast evolution with short rise times of 5-10 days and rapid post-peak decline rates of about 0.1 mag day⁻¹, we identify a significant subset (roughly ten objects) with slower declines and noticeable light-curve undulations, suggesting varying CSM density or prolonged interaction. The constructed absolute-magnitude template yields an average Mr = –19.246 ± 0.495, placing Type Ibn SNe at the brighter end of the interacting supernova population.

We find no systematic correlation between peak brightness and colour, indicating that Ibn explosions span a broad intrinsic colour range rather than being governed by a single physical parameter. Spectral analysis separates the two class of events as P-cygni and emission sub-class. The spectral Equivalent Widths showed correlations with g-i colors separating the two sub-population. The analysis suggests that Type Ibn supernovae occupy a wider physical parameter space than implied by their defining spectroscopic classification.

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