SN 2024hpj: A perspective on SN 2009ip-like events

¹ INAF–Osservatorio Astronomico di Capodimonte Salita Moiariello 16 80131 Napoli, Italy
² INAF-Osservatorio Astronomico di Padova Vicolo dell’Osservatorio 5 35122 Padova, Italy
³ Dipartimento di Fisica e Astronomia “Galileo Galilei”, Università degli Studi di Padova Vicolo dell’Osservatorio 3 35122 Padova, Italy
⁴ Yunnan Observatories, Chinese Academy of Sciences Kunming 650216, P.R. China
⁵ International Centre of Supernovae, Yunnan Key Laboratory Kunming 650216, P.R. China
⁶ Institute of Space Sciences (ICE, CSIC), Campus UAB, Carrer de Can Magrans s/n 08193 Barcelona, Spain
⁷ School of Physics, University College Dublin, L.M.I. Main Building Beech Hill Road Dublin 4 D04 P7W1, Ireland
⁸ Institut d’Estudis Espacials de Catalunya (IEEC) 08860 Castelldefels (Barcelona), Spain
⁹ The Oskar Klein Centre, Department of Astronomy, Stockholm University AlbaNova 106 91 Stockholm, Sweden
¹⁰ Finnish Centre for Astronomy with ESO (FINCA), University of Turku 20014 Turku, Finland
¹¹ Department of Physics and Astronomy, University of Turku 20014 Turku, Finland
¹² Department of Physics, University of Warwick Gibbet Hill Road Coventry CV4 7AL, UK
¹³ Nordic Optical Telescope, Aarhus Universitet, Rambla José Ana Fernández Pérez 7, local 5 E-38711 San Antonio Breña Baja Santa Cruz de Tenerife, Spain
¹⁴ Department of Applied Physics, School of Engineering, University of Cádiz Campus of Puerto Real E-11519 Cádiz, Spain
¹⁵ Università degli Studi di Padova (UNIPD), Dipartimento di Fisica e Astronomia “G. Galilei” Via F. Marzolo 8 35131 Padova, Italy
¹⁶ INAF – Osservatorio Astronomico di Brera Via E. Bianchi 46 I-23807 Merate (LC), Italy
¹⁷ Instituto de Alta Investigación, Universidad de Tarapacá Casilla 7D Arica, Chile
¹⁸ Tuorla Observatory, Department of Physics and Astronomy, 20014 University of Turku Vesilinnantie 5 Turku, Finland
¹⁹ Cosmic DAWN Centre, Niels Bohr Institute, University of Copenhagen Jagtvej 128 2200 København N, Denmark
²⁰ Astrophysics sub-Department, Department of Physics, University of Oxford Keble Road Oxford OX1 3RH, UK
²¹ Astrophysics Research Centre, School of Mathematics and Physics, Queen’s University Belfast Belfast BT7 1NN, UK
²² INAF-Osservatorio Astronomico d’Abruzzo Via M. Maggini snc 64100 Teramo, Italy
²³ School of Astronomy and Space Science, University of Chinese Academy of Sciences Beijing 100049, China
²⁴ National Astronomical Observatories, Chinese Academy of Sciences Beijing 100101, China

^★ Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Received: 19 August 2025
Accepted: 23 December 2025

Abstract

Supernovae (SNe) IIn are terminal explosions of massive stars that are surrounded by a dense circumstellar medium (CSM). Among SNe IIn, a notable subset is the SN 2009ip-like, which exhibits an initial, fainter peak attributed to stellar variability in the late evolutionary stages, followed by a brighter peak, interpreted as the SN explosion itself. In this context, we analysed the spectrophotometric evolution of SN 2024hpj, an object with a triple-peaked light curve and spectra typical of a SN IIn but with a complex line profile composed of broad P-Cygni features topped by narrow emissions. Comparing it with other SN 2009ip-like events in the literature, as well as with other unpublished objects (SNe 2019mry, 2022ytx, 2024uzf, and 2025csc), we identify star-forming regions as their preferred formation environment. On the other hand, the diversity of spectrophotometric features within the sample suggests that variations in CSM mass and distribution may influence the observed characteristics. We identify four sub-classes based on the luminosity and rapidity of the light curve evolution, which provides insights into possible differences in the progenitors, while a statistical analysis of their observed rate indicates progenitor masses around 25 − 31 M_⊙ or lower.