During the summer months, there is a unique opportunity to witness the eruption of a nova in the constellation Corona Borealis. This event, taking place about 3,000 light-years away from Earth, is caused by a white dwarf star orbiting a red giant that accumulates enough material to trigger a blast visible to the naked eye for a few days to a week. Known as T Corona Borealis, this binary system has erupted around every 80 years, with the last eruption occurring in 1946. Scientists are observing changes in T CrB that suggest the nova could occur between now and September.
The name “nova” originates from Tycho Brahe’s report in 1573 about a new object in the sky. Novas are now known to be explosions from white dwarfs that have accumulated material from companion stars. The material accretion triggers a blast when the pressure and temperature reach a critical point. T CrB demonstrates a pattern of brightening and then dimming activity, similar to observations before previous eruptions in 1946 and 1866. Scientists are excited to study this nova and unravel the mysteries of white dwarf eruptions.
Corona Borealis is easy to spot in the night sky, located between the bright stars Vega and Arcturus. If you trace an arc from the Big Dipper’s handle to Arcturus, you will come across the semicircle of stars that form the Northern Crown constellation. The nova will appear just outside this semicircle. Scientists are using numerous telescopes worldwide and in space to capture detailed observations of the event, hoping to answer questions about mass changes in white dwarfs following novas and the impact of the eruption on the surrounding nebula.
One of the main questions scientists aim to solve is whether the white dwarf in T CrB gains or loses mass due to the nova. This information is crucial to understanding the evolutionary stages of star systems and galaxies. Observations of high-energy gamma rays from novas, like the one detected in the V407 Cygni binary system in 2010, have also raised new questions about the energetics of these events. While scientists may have limited warning before the T CrB eruption, they are eager to observe this cosmic spectacle and gain insights into the formation of stars, planets, and dust.
The eruption of T CrB could provide crucial information about how white dwarf novas impact their surroundings and potentially lead to even more explosive events in the future. Additional mysteries surround the propagation of shock waves and the formation of dust in the nebula, contributing to our understanding of galactic evolution. While the exact timing of the nova remains uncertain, astronomers are hopeful that amateurs and scientists alike will have the opportunity to witness this extraordinary event in the night sky and contribute to our knowledge of the universe.