Astronomers have predicted how many supernovas or exploding stars should be out there, but the existing optical space telescopes aren’t able to find as many supernovas in the universe as expected. A study published in Monthly Notices of the Royal Astronomical Society explains this discrepancy, and it is due to dust.
A supernova is a huge and bright phenomenon that usually occurs at the end of a star’s lifetime. Data from NASA’s retired Spitzer Space Telescope has allowed scientists to spot five previously unknown supernovas in dusty galaxies. Spitzer observed the universe in infrared light, allowing it to see through clouds of dust that hampered the view for optical telescopes.
Spitzer data came in handy
“These results with Spitzer show that the optical surveys we’ve long relied on for detecting supernovas miss up to half of the stellar explosions happening out there in the universe,” lead author Ori Fox said in a NASA statement. “It’s very good news that the number of supernovae we’re seeing with Spitzer is statistically consistent with theoretical predictions.”
The supernovas found in the Spitzer study had a similar fate. “As they grow old and their cores fill with iron, the big stars can no longer produce enough energy to withstand their own gravity, and their cores collapse, suddenly and catastrophically,” NASA said. The space agency described the star explosions as “blowing themselves to smithereens.”
Mission for upcoming telescopes
The discovery of hidden supernovas will allow the upcoming infrared space telescopes such as the James Webb Space Telescope to look for something as they gaze through the universe. The space agency bid adieu to Spitzer last year after operating it for almost 17 years.
Supernovas represent the deaths of stars, but they can enable astronomers to understand star births as well. “If you have a handle on how many stars are forming, then you can predict how many stars will explode,” Fox said. “Or, vice versa, if you have a handle on how many stars are exploding, you can predict how many stars are forming. Understanding that relationship is critical for many areas of study in astrophysics.”
