Successful MeerKAT survey finds new millisecond pulsars
Using the MeerKAT radio telescope in South Africa, an international team of astronomers has discovered three new millisecond pulsars in the globular cluster Messier 62, also known as NGC 6266.
Pulsars are highly magnetized rotating neutron stars that emit electromagnetic rays. Astronomers suggest that millisecond pulsars (MSPs), which rotate at very high speeds — less than 30 milliseconds are likely to form in binary systems where the more massive star becomes neutron and spins up by accreting material from the second star.
A team of astronomers led by Leila Vlieshower from the University of Manchester (UK) published a paper reporting the discovery of three new pulsars of this type in Messier 62, where seven double pulsars are already known. The discovery was made within the framework of the project TRansients and PUlsars with MeerKAT (TRAPUM).
Three discovered millisecond pulsars turned out to be binary systems. This makes all 10 pulsars known to date in Messier 62 double. Scientists are surprised that only double pulsars are found in this cluster, unlike other known clusters where isolated pulsars are more easily found.
One of the new pulsars, M62H, has a rotation period of about 3.7 milliseconds. Its companion has a minimum mass of approximately 0.00236 solar masses (2.5 Jupiter masses), making M62H the lightest binary system known. The orbital period of the system is 0.133 days.
Another pulsar, M62I, rotates once every about 3.3 milliseconds and has an orbital period of about 0.51 days. And its satellite has a minimum mass of 0.15 solar masses. The data also allowed astronomers to determine the age of M62I, which is at least 278 million years old.
Pulsar M62J has a rotation period of 2.76 milliseconds. Scientists have not yet been able to determine other properties of this pulsar.
In addition to the discovery of three new pulsars in Messier 62, the authors of the paper updated data on six previously known pulsars in this cluster, using information from the last 23 years.