Astronomers have made one of the highest-resolution observations in the history of astronomy. They observed a distant pulsar 6,500 light-years from Earth.
So, a team of astronomers has observed two intense regions of radiation, 20 km apart, around a star 6,500 light-years away. We are talking about a pair of stars orbiting each other. One is a rapidly spinning star, a pulsar called B1957+20. The other is a brown dwarf, a failed star, which is only about a third the diameter of our Sun. The brown dwarf features a “wake” or comet-like tail of gas. The interesting thing is they are using the universe as a magnifying glass.
“The gas is acting as like a magnifying glass right in front of the pulsar,” says Robert Main, lead author of the paper describing the observation being published May 24 in the journal Nature. “We are essentially looking at the pulsar through a naturally occurring magnifier which periodically allows us to see the two regions separately.”
This plasma lensing has magnified some of the pulsar’s radio emission by a factor of 70 to 80. Therefore, massively boosting astronomers’ ability to observe these small, close-in regions.
In this event the pulsar is stealing gas from its stellar companion, thus destroying it. The pulsar spins more than 600 times a second. Researchers also indicate it may be one of the most massive pulsars they’ve ever discovered.
Because of the close distance, the pulsar is blowing strong radiation to its companion brown dwarf. Thus, heating one side of the relatively cool dwarf star to the temperature of our Sun, or some 6000°C.
So, for this observation, researchers have used data collected from the Arecibo Observatory in Puerto Rico. It’s one of the highest-resolution observations in astronomical history. To better understand it, this is just like pointing a telescope at Pluto and being able to see something the size of a flea on its surface. Very neat, isn’t it?
However, the new study could be a clue to the nature of mysterious phenomena known as Fast Radio Bursts, or FRBs.
“Many observed properties of FRBs could be explained if they are being amplified by plasma lenses,” said Main. “The properties of the amplified pulses we detected in our study show a remarkable similarity to the bursts from the repeating FRB, suggesting that the repeating FRB may be lensed by plasma in its host galaxy.”
Thumbnail image: You can see the black widow pulsar B1957+20 passing behind its brown dwarf companion (foreground) in this artist’s concept. Credit: Dr. Mark A. Garlick; Dunlap Institute for Astronomy & Astrophysics, University of Toronto.