California, USA – An international team of astronomers recently discovered a Type Ibn supernova called SN 2023fyq and conducted extensive observations to understand its precursor activity. The results of their study, published on the pre-print server arXiv, revealed intriguing details about the supernova’s behavior before its explosion.
Supernovae are significant astronomical events that provide crucial insights into the life cycle of stars and galaxies. They are classified into different types based on their atomic spectra, with Type I lacking hydrogen and Type II displaying hydrogen lines. Type Ibn supernovae, a subclass of interaction-powered supernovae, exhibit narrow helium lines in their spectra and have short-lived light curves resembling fast-evolving transients.
SN 2023fyq was discovered by the Zwicky Transient Facility in April 2023 and classified as a Type Ibn supernova after experiencing a rapid re-brightening in June of the same year. Located in the galaxy NGC 4388, approximately 59 million light-years away, SN 2023fyq’s intriguing behavior caught the attention of astronomers worldwide.
Led by Yize Dong from the University of California, Davis, the team investigated the supernova’s history dating back to 2019 and monitored its development through various ground-based observatories. By analyzing data collected over several years, they uncovered a pattern of precursor emission leading up to the supernova explosion, with a notable rise in activity occurring in the final 100 days before the event.
The observations suggest that the precursor activity in SN 2023fyq can be attributed to mass transfer within a binary system comprising a low-mass helium star and a compact companion. The findings indicate a significant expansion of the helium star, triggering mass transfer to the companion in the months leading up to the explosion. This mass transfer event produced the precursor emission detected by astronomers.
As the binary system continued its evolution, the orbit between the two objects shrank, causing an increase in the accretion rate onto the companion and a subsequent rise in the light curve. The final stages before the explosion, marked by core silicon burning or mass transfer-induced eruptive mass ejection, led to the eventual supernova event.
In conclusion, the researchers propose two potential scenarios for the supernova explosion: either a core collapse of the helium star or a merger between the helium star and its companion. The study sheds light on the complex processes involved in stellar evolution and highlights the importance of continuous monitoring and analysis of astronomical phenomena.