Astronomers have discovered 10 new millisecond-plus stars in the globular cluster Terzan 5 using data from the MeerKAT radio telescope and NSF's Green Bank Telescope.
This Hubble Space Telescope image shows the star cluster Terzan 5. Image credit: F. Ferraro / NASA / ESA / ESO.
Star Cluster Terzan 5 It is a dense home to hundreds of thousands of different kinds of stars.
Also known as ESO 520-27 and 2MASX J17480455-2446441, it is located about 19,000 light-years away in the constellation Sagittarius.
“Terzan 5 is one of the most extensively studied globular clusters in history, and has produced remarkable results across multiple wavelengths,” said Scott Ransom, an astronomer at the National Radio Astronomy Observatory, and his colleagues.
“It is located in the inner bulge of the Milky Way and is thought to be the remnant of a primitive structure essential for the formation of galaxies.”
“Terzan 5 is massive (1.09 million times the mass of the Sun) and has one of the highest stellar encounter rates in globular clusters.”
“This coincides with Terzan 5 holding the record for the largest number of ms-plus stars identified in a globular cluster (39 prior to this study), with over 50% of those in binary systems (20 prior to this study).”
The ten new pulsars were discovered as part of the MeerKAT (TRAPUM) Large-Scale Survey of Transients and Pulsars project.
“It's very unusual to find a new exotic pulsar,” Dr Ransom said.
“But what's really interesting is that these strange people exist in such a diverse range of forms within one group.”
Using data from the MeerKAT telescope, the authors were able to determine the approximate location of each pulsar by tracking and measuring its rotation rate.
Archived data from the Green Bank Telescope has revealed strange and unusual details about these stars.
“Without the Green Bank Telescope archives, we would never have been able to characterize these pulsars and understand their astrophysics,” Dr Ransom said.
“This data allowed us to pinpoint the pulsar's location in the sky, measure its specific motion, and see how its orbit has changed over time.”
Among their discoveries, astronomers found two binary star systems, likely neutron stars, pulled into each other's orbit.
Of the 3,600 known pulsars in the Milky Way Galaxy, only 20 have been confirmed as double neutron star binaries.
When pulsars pair up in a binary system, the gravitational attraction of one to the other can strip matter and energy away, causing one to spin even faster and become a millisecond pulsar.
The pair is a new candidate for the fastest spinning pulsar in a double neutron star system, and has the longest orbit of its kind, potentially breaking the record.
Currently, the record holder for the fastest spinning pulsar is already held by Terzan 5.
In addition to the five binary systems already known in the cluster, the researchers also observed three unusual new pulsar “spider” binary systems.
“The discovery of these strange pulsars provides a better understanding of globular clusters and neutron stars, further tests Einstein's theory of general relativity, and expands our knowledge of the pulsar category,” the researchers said.
Their work Published in a journal Astronomy and Astrophysics.
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PV Padmanab others2024. Discovery and Timing of Ten New Millisecond Pulsars in the Globular Cluster Terzan 5. A&A 686, A166; doi: 10.1051/0004-6361/202449303
Source: www.sci.news
