For this new work, two Caltech astronomers — graduate student Dillon Dong and his doctoral adviser, Gregg Hallinan — compared a VLASS observation from January 2018 with one taken by the VLA in 1998 as part of the VLA’s Faint Images of the Radio Sky at Twenty-centimeters survey.
They discovered 20 transient objects in the newer image that did not exist in the older image. One object in particular, VT 1137-0337, located in a dwarf galaxy 395 million light-years from Earth, caught their eye.
“This one stood out because its galaxy is experiencing a burst of star formation, and also because of the characteristics of its radio emission,” Dong said in a statement.
That radio emission shows similarities to a known pulsar wind nebula — the Crab Nebula in the constellation Taurus — but it’s much more powerful. “The object we have found appears to be approximately 10,000 times more energetic than the Crab, with a stronger magnetic field,” Dong said. “It likely is an emerging ‘super Crab.'”
Emerging is right: VT 1137-0337 is extremely young by astronomical standards. Hallinan estimates it’s between 14 and 80 years old, which would make it one of the youngest neutron stars ever observed.
There is a chance, however, that this energetic object is not a nebula wind pulsar at all. Instead, it might be a magnetar, a neutron star with an extremely powerful magnetic field that might be the source of mysterious flashes called fast radio bursts.
“In that case, this would be the first magnetar caught in the act of appearing, and that, too, is extremely exciting,” Dong said.
The researchers will continue to study VT 1137-0337, monitoring it via subsequent VLASS observations. So far, the object has shown up in images each year since 2018.
Dong and Hallinan presented their research at the 240th meeting of the American Astronomical Society, in Pasadena, California.