Search for Luminous Blue Variables in large sky surveys

The project aims to search for new Luminous Blue Variable (LBV) candidates in large-scale time-domain sky surveys such as the Legacy Survey of Space and Time (LSST) and the Zwicky Transient Facility (ZTF), and to perform their subsequent analysis.

The LBV phase is a critical stage in the lifetime of a high-mass star (40 M⊙ < M< 90 M⊙), during which the star loses a significant fraction of its initial mass through strong stellar winds and occasional giant eruptive events. This phase therefore plays a key role in defining the properties of pre-supernova stars. LBVs attract considerable attention because of their importance for understanding massive star evolution. During the LBV phase, the stars exhibit both short-term stochastic variability and long-term variability (the so-called S Dor cycle), which is accompanied by changes in effective temperature and thus by variations in spectral type. In addition, several LBVs have shown another type of outburst — giant eruptions — characterised by dramatic increases in bolometric luminosity and visual brightness.

Depending on the student’s interests, the project may involve developing new numerical techniques for fast classification of transients and identifying LBVs undergoing eruptions, or studying already known SN impostors and estimating their parameters and evolutionary status.

References:

[1] Humphreys R. M., Davidson K., The Luminous Blue Variables: Astrophysical Geysers, 1994, PASP, 106, 1025
[2] Weis K., Bomans D. J., Luminous Blue Variables, 2020, Galaxies, 8, 20
[3] Maryeva O., et al., The History Goes On: Century Long Study of Romano's Star, 2019, Galaxies, 7, 79
[4] Maryeva O., et al., How long can luminous blue variables sleep? A long-term photometric variability and spectral study of the Galactic candidate luminous blue variable MN 112, 2022, MNRAS, 513, 5752
[5] Maryeva O., et al., Wray 15–906: a candidate luminous blue variable discovered with WISE, Herschel, and SALT, 2020, MNRAS, 498, 5093