(ORDO NEWS) — An international team of astronomers has made photometric and spectroscopic observations of SN 2020jfo, a type II supernova.
Type II supernovae (SN II) are explosions of massive stars (greater than eight solar masses) that collapse to form a compact object, either a neutron star or a black hole.
They differ from other varieties of supernovae by the presence of hydrogen lines in their spectra. According to the shape of the light curves showing the change in brightness over time, two categories are distinguished, type IIL and type IIP.
The former exhibits a steady linear decay after the explosion, while the latter exhibits a slow decrease in brightness followed by a normal decay.
SN 2020jfo was discovered on May 6, 2020 using the Samuel Oshin telescope of the Palomar Observatory as part of the Zwicky Transient Facility astronomical survey of the sky, the purpose of which is to search for transients – objects that change their brightness.
The star flared on the outskirts of the spiral galaxy M61, located at a distance of about 47.3 million light-years from Earth.
Photometric and spectroscopic observations in the ultraviolet and optical/near infrared ranges were carried out starting from the third day after the explosion for 431 days.
They showed that the plateau phase was relatively short and lasted about 67 days, and the peak of the apparent brightness of the supernova turned out to be weaker than outbursts with the same or shorter plateau duration.
At the same time, the spectral features associated with the absorption of radiation by neutral hydrogen atoms turned out to be strong, which indicates a large mass of the hydrogen shell ejected during the explosion.
The spectra also show rather strong metal lines compared to other type II supernovae with comparable plateau lengths.
According to the researchers, the mass of the progenitor star is between 12 and 15 solar masses, while 13.7 solar masses were ejected, which is much higher than other SN II.
Contact us: [email protected]