Astronomers report that an ultra-rare space object has been discovered in the Milky Way

(ORDO NEWS) — A new member of the category of stars so rare we can count a known number on our fingers and toes has just been discovered in the Milky Way.

It is called MAXI J1816-195, located no more than 30,000 light-years from us. Preliminary observations and studies indicate that it is an accreting X-ray millisecond pulsar, of which only 18 others are known, according to the pulsar database compiled by astronomer Alessandro Patruno.

With such a small number, any new object is an extremely exciting find that can provide important statistical information about how these objects form, develop and behave.

The opening is indeed ready to be printed. The X-ray emission from the object was first detected on June 7 by the Japan Space Agency’s All-Sky X-ray Imaging (MAXI) instrument mounted outside the ISS.

In a notice. published in The Astronomer’s Telegram (ATel), a team led by astrophysicist Hitoshi Negoro from Nihon University in Japan reported that they have discovered a previously uncatalogued X-ray source located in the galactic plane between the constellations of Sagittarius, Scutum and Serpens. It flashed relatively brightly, they said, but they were unable to identify it based on the MAXI data.

It wasn’t long before other astronomers jumped on him. Using the Neil Gerels Swift Observatory, a space telescope, astrophysicist Jamie Kenny of Pennsylvania State University and colleagues determined the location to confirm the detection with an independent instrument and localize it.

Swift saw the object in X-rays, but not in optical or ultraviolet light, at the location indicated by the MAXI observations.

“This location is not at the location of any known cataloged X-ray source, so we agree that this is a new transient source, MAXI J1816-195,” they wrote in a notice posted to ATel.

“Furthermore, archival Swift/XRT observations of this region, made in 2017 June 22, did not reveal any point source at this location.”

Everything is more and more interesting.

Next up was the Neutron Star Internal Composition Investigator (NICER), a NASA X-ray instrument also installed on the ISS, in an investigation led by astrophysicist Peter Balt of NASA’s Goddard Space Flight Center.

And then it all started. get really interesting. NICER recorded X-ray pulses at 528.6 Hz, suggesting that this thing is spinning at 528.6 times per second, in addition to the X-ray fusion explosion.

“This is a discovery,” they wrote. , “shows that MAXI J1816-195 is a neutron star and a new accreting millisecond X-ray pulsar.”

So what does this mean? Well, not all pulsars are the same. At its most basic level, a pulsar is a type of neutron star, which is the collapse of the core of a dead massive star that has gone supernova.

These objects are very small and very dense about 2.2 times the mass of the Sun packed into a sphere only 20 kilometers (12 miles) or so in diameter.

To be classified as a pulsar, a neutron star must… pulsate. Rays of radiation are launched from its poles; due to the way the star is angled, these beams pass by the Earth like the beams of a beacon. Millisecond pulsars spin so fast that they pulse hundreds of times per second.

Some pulsars are powered solely by rotation, but other types are powered by accretion. The neutron star is in a binary system with another star, their orbits are so close that matter is pumped from the companion star to the neutron star.

This material is sent along the neutron star’s magnetic field lines to its poles, where it falls to the surface, forming hot spots that flare brightly in the X-rays.

In some cases, the accretion process can be accelerated. pulsar to millisecond rotation speed. It is an accreting X-ray millisecond pulsar, and MAXI J1816-195 appears to be in this rare category.

The thermonuclear X-ray burst detected by NICER was likely the result of unstable thermonuclear burning of material accumulated by the companion star.

Because the discovery is so new, observations at multiple wavelengths are ongoing. Follow-up observations have already been made using Swift, and the 2m Liverpool Telescope in the Canary Islands of La Palma in Spain has been used to search for an optical counterpart, although none have been found. Other astronomers are also invited to board the MAXI J1816-195 train.

In the meantime, a full time analysis of the pulsar is underway, which Bult and his team say will spread as more data becomes available. You can follow the news on ATel.

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