This artist’s concept shows the nova system HM Sagittae , where a white dwarf star is pulling material from its red giant companion. This forms a blazing hot disk around the dwarf, which can unpredictably undergo a spontaneous thermonuclear explosion as the infall of hydrogen from the red giant grows denser and reaches a tipping point. These fireworks between companion stars are fascinating to astronomers by yielding insights into the physics and dynamics of stellar evolution in binary systems.
“When I first saw the new data, I went – ‘wow this is what Hubble UV spectroscopy can do!’ – I mean it’s spectacular, really spectacular.”“In 1975 HM Sge went from being a nondescript star to something all astronomers in the field were looking at, and at some point that flurry of activity slowed down,” said Ravi Sankrit of the Space Telescope Science Institute in Baltimore.
SOFIA soars over the snow-covered Sierra Nevada mountains with its telescope door open during a test flight. SOFIA is a modified Boeing 747SP aircraft. SOFIA achieved full operational capability in 2014 and concluded its final science flight on September 29, 2022. Credit: NASA/Jim RossWith data from NASA’s flying telescope SOFIA, which retired in 2022, the team was able to detect the water, gas, and dust flowing in and around the system.