Three scientists received the Nobel Prize in 2011 for their work on discovering that the universe is expanding at an ever-accelerating rate by observing distant supernovae.
Now, a team of Indian astronomers has further provided clues of the possible mechanisms of supernovae explosions, providing key measures of cosmological distances.
Catastrophic yet spectacular
Their study of a supernova called SN 2017hpa (Type Ia supernovae) helped narrow down the mechanism of supernovae by observing unburned carbon in the early phase spectra.
The death of a star as a supernova is one of the most destructive yet spectacular events in the universe. Type Ia supernovae occur due to explosions of a white dwarf that exceed their mass beyond the Chandrasekhar limit through accretion of matter.
Explosion mechanisms still a mystery
Their homogeneous nature allows astronomers to measure cosmological distances. However, the mechanisms of an explosion that create these supernovae (SNe) are yet to be understood completely. While most SNe Ia are homogeneous, many such events show diversity in their spectral properties and light curve.
“It is very important to study more such exotic objects from the very early hours of explosion to very late phase to place tighter constraints on the explosion mechanism as well as the progenitor system,” said Anirban Dutta, researcher of the study.
Recently, Indian astronomers discovered over 200 new variable stars in the Pacman Nebula. The nebula is located 9,500 light-years away from Earth, which is a close distance in astronomical terms. A team of scientists from the Aryabhatta Research Institute of Observational Science investigated a cosmic gas cloud using the 3.6-meter Devasthal Optical Telescope (DOT) in Uttarakhand, India.
The team found 228 new variable stars, out of which, 81 were cluster members. Stars that belong to the same cluster are believed to have formed at nearly the same time and also have the same composition. However, there is a difference in their mass. The other 147 variable stars are assumed to belong to the field population, which means they are located in the same area but have different characteristics.
