Current sky surveys are discovering a harvest of novel types of
stellar transients that cannot be explained with traditional explosion
channels. Their number expected to dramatically increase in the
Synoptic Survey Telescope (LSST) era. The LSST will discover objects
soon after the outburst onset and will provide well-sampled multi-band
light curves through both the main and ancillary surveys. Thanks to
the multiple survey strategies, we will discover and monitor
transients in different time domains, and we will study transients
evolving with different time scales.
One of the research fields that will largely take advantage from LSST is that of the so-called Intermediate-Luminosity Optical Transients or Gap Transients (e.g. Kasliwal 2007, Pastorello & Fraser 2019, Nature Astronomy, 3, 676 ; see also Noam Soker’s pages). These transients, with absolute magnitudes intermediate between those of core-collapse supernovae (SNe) and classical novae (-9 > MV > -15), are challenging our observational and theoretical knowledge of stellar evolution.
The main goal of this project is the characterization of the different
types of ILOTs on the basis of their observational parameters
(long-duration photometric monitoring, spectroscopic evolution of the
outbursts, and information on the quiescent progenitors through the
analysis of high spatial resolution pre- and post-outburst images).
In this project, the following classes of Gap Transients will not be
considered: low-luminosity stripped-envelopes SNe (SNe Iax, Ca-rich
transients, .Ia candidates, or other faint SNe I; e.g. Kasliwal 2013,
IAU Symposium 2013; Valenti et al. 2009, Nature, 459, 674; Tomasella et al. 2020, MNRAS submitted, arXiv: 2002.00393 ), and
low-luminosity Type II-P events (Pastorello et al. 2004, MNRAS, 347,
74; Spiro et al. 2014, MNRAS, 439, 2873).
We will study in detail the following categories:
- Giant LBV eruptions of very massive stars and pre-SN outbursts
- Ordinary S Dor-type variability
- Intermediate-Luminosity Red Transients (ILRTs)
- Luminous Red Novae (LRNe)
- Outbursts of Young Stellar Objects (YSO)
People directly involved in this project:
Andrea Pastorello (INAF-OAPd), Enrico Cappellaro (INAF-OAPd), Elena Mason (INAF-OATs), Yongzhi Cai (Tsinghua University, INAF-OAPd), Andrea Reguitti (Universidad Andres Bello, INAF-OAPd), Giorgio Valerin (Padova University, INAF-OAPd), Leonardo Tartaglia (Stockholm University), Paolo Ochner (Padova University), Nancy Elias-Rosa (INAF-OAPd), Giuliano Pignata (Universidad Andres Bello), Elena Barsukova (SAO, Russian Academy of Sciences), Vitaly Goranskij (SAI, Moskov University).
Morgan Fraser (University College Dublin), Emma Callis (University College Dublin), Antonia Morales-Garoffolo (Universidad de Cadiz), Maria Teresa Botticella (INAF-OACn), Massimo Della Valle (INAF-OACn), Erkki Kankare (University of Turku), Thomas Reynolds (University of Turku) Rubina Kotak (University of Turku), Paolo Mazzali (Liverpool University), Maximilian Stritzinger (Aarhus University), the Padova-Asiago Supernova Group.