(Source: University of Sydney)
A signal from deep in the Milky Way is tantalising scientists
International student Ziteng Wang detected unusual signals from deep in the heart of the Milky Way using CSIRO’s ASKAP radio telescope. Now astronomers are on the search for more evidence of what type object could be emitting them.
Astronomers have discovered unusual signals coming from the direction of the Milky Way’s centre. The radio waves fit no currently understood pattern of variable radio source and could suggest a new class of stellar object.
“The strangest property of this new signal is that it is has a very high polarisation. This means its light oscillates in only one direction, but that direction rotates with time,” said Ziteng Wang, lead author of the new study and a PhD student in the School of Physics at the University of Sydney.
“The brightness of the object also varies dramatically, by a factor of 100, and the signal switches on and off apparently at random. We’ve never seen anything like it.”
Many types of star emit variable light across the electromagnetic spectrum. With tremendous advances in radio astronomy, the study of variable or transient objects in radio waves is a huge field of study helping us to reveal the secrets of the Universe. Pulsars, supernovae, flaring stars and fast radio bursts are all types of astronomical objects whose brightness varies.
“At first we thought it could be a pulsar – a very dense type of spinning dead star – or else a type of star that emits huge solar flares. But the signals from this new source don’t match what we expect from these types of celestial objects,” Mr Wang said.
The discovery of the object has been published today in the Astrophysical Journal.