Supernovas are spectacular cosmic events by definition as they can become more bright than an entire galaxy. A supernova is the explosion of a star as soon as it loses its fuel, and the outcome will be a white dwarf, which is the stellar extremely dense kernel that remains after the blast.
However, astronomers had been witnessing so many times how cosmic events shift away more or less from the predicted outcome. The same happens with a peculiar white dwarf star that wanders throughout the Milky Way.
The white dwarf SDSS J1240+6710 enters the scene
The white dwarf known as SDSS J1240+6710 is located 1,430 light-years away from Earth, and it captured the attention of astronomers since 2015. By using the Hubble Space Telescope, researchers led by Boris Gänsicke, who is an astrophysicist from the University of Warwick in England, came to the conclusion that the distant space object is defying the standard model of white dwarfs. Besides having an odd composition and mass, the white dwarf was also traveling about 560,000 miles per hour towards the opposite direction of the way the host galaxy is rotating.
Lead author Boris Gänsicke declared:
“When we found this unusual white dwarf was really low in mass and really moving fast, that really triggered my curiosity into what happened to it in its past,”
The researchers involved in the new study believe that the culprit for the peculiar characteristics of the white dwarf star could be a “partial supernova” that blasted what remained of the object across our Milky Way galaxy. The miniatured supernova was weak enough to leave behind the most part of a white dwarf.
Gänsicke further added:
“That’s what makes this white dwarf unique — it did undergo nuclear burning, but stopped before it got to iron,”
“When it had its supernova event, it was likely just brief, maybe a couple of hours.”
The scientists involved detailed their findings in the journal Monthly Notices of the Royal Astronomical Society here: https://academic.oup.com/mnras/article/496/4/4079/5860288