by Jonathan Deal for MSFC News
Huntsville AL (SPX) Jun 07, 2024
This summer, astronomers around the world, both professional and amateur, will focus on a small constellation in the night sky. The focus is on a dark spot in the Corona Borealis, where a bright nova event, visible to the naked eye, is expected.
"It"s a once-in-a-lifetime event that will create a lot of new astronomers out there, giving young people a cosmic event they can observe for themselves, ask their own questions, and collect their own data," said Dr. Rebekah Hounsell, an assistant research scientist specializing in nova events at NASA"s Goddard Space Flight Center in Greenbelt, Maryland. "It"ll fuel the next generation of scientists."
T Coronae Borealis, known as "T CrB" or the "Blaze Star," is a binary system located 3,000 light-years from Earth in the Northern Crown. It consists of a white dwarf and a red giant. The white dwarf strips hydrogen from the red giant, leading to periodic thermonuclear explosions on its surface. These events typically occur every 80 years.
Dr. Hounsell emphasized the difference between a nova and a supernova. "Don"t confuse a nova with a supernova, a final, titanic explosion that destroys some dying stars," Hounsell said. "In a nova event, the dwarf star remains intact, sending the accumulated material hurtling into space in a blinding flash. The cycle typically repeats itself over time, a process which can carry on for tens or hundreds of thousands of years."
Finding T Coronae Borealis
The first recorded sighting of the T CrB nova was in 1217 by Burchard, abbot of Ursberg, Germany. The last observed eruption was in 1946. Recent behavior suggests another eruption could occur by September 2024.
Stargazers should look to the horseshoe-shaped Northern Crown west of the Hercules constellation. It can be found by tracing a line between the bright stars Arcturus and Vega. The nova will be visible for less than a week.
A coordinated scientific approach
Dr. Elizabeth Hays, chief of the Astroparticle Physics Laboratory at NASA Goddard, noted the enthusiasm among amateur astronomers. "Citizen scientists and space enthusiasts are always looking for those strong, bright signals that identify nova events and other phenomena," Hays said. "Using social media and email, they"ll send out instant alerts, and the flag goes up. We"re counting on that global community interaction again with T CrB."
NASA's Fermi Gamma-ray Space Telescope, along with other space-based missions such as the James Webb Space Telescope, Neil Gehrels Swift Observatory, IXPE, NuSTAR, NICER, and ESA"s INTEGRAL, will observe the nova. Ground-based telescopes, including the Very Large Array in New Mexico, will also contribute. These observations will cover various wavelengths of light.
"We"ll observe the nova event at its peak and through its decline, as the visible energy of the outburst fades," Hounsell said. "But it"s equally critical to obtain data during the early rise to eruption - so the data collected by those avid citizen scientists on the lookout now for the nova will contribute dramatically to our findings."
Researchers hope to gain insights into the structure and dynamics of recurring stellar explosions. "Typically, nova events are so faint and far away that it"s hard to clearly identify where the erupting energy is concentrated," Hays said. "This one will be really close, with a lot of eyes on it, studying the various wavelengths and hopefully giving us data to start unlocking the structure and specific processes involved. We can"t wait to get the full picture of what"s going on."
Newer tools like gamma-ray imagers and IXPE"s polarization capability will provide unprecedented insights into binary systems and their processes.
While there is no certainty that the nova will occur in September, experts remain hopeful. "Recurrent novae are unpredictable and contrarian," said Dr. Koji Mukai, an astrophysics researcher at NASA Goddard. "When you think there can"t possibly be a reason they follow a certain set pattern, they do - and as soon as you start to rely on them repeating the same pattern, they deviate from it completely. We"ll see how T CrB behaves."
Related Links
Astroparticle Physics Laboratory
Stellar Chemistry, The Universe And All Within It