A new member of a class of stars so rare that we can count the known number of them on fingers and toes in the Milky Way has been discovered.
It’s called MAXI J1816-195, and it’s no more than 30,000 light-years away. Initial observations and investigations indicate that it is a millisecond X-ray accreting pulsar – of which only 18 others are known, According to the pulsar database Compiled by astronomer Alessandro Patrono.
When the numbers are low, any new organism represents a very exciting discovery that can provide important statistical information about how these organisms formed, evolved and behaved.
Finding really hot about presses. X-ray light emitted from the object was first detected on June 7 by the Japan Space Agency’s X-ray Image Monitor (MAXI) instrument installed on the exterior of the International Space Station.
in Notice posted on The Astronomer’s Telegram (ATel), a team led by astrophysicist Hitoshi Negoro of Nihon University in Japan has published that they have identified a previously unindexed X-ray source, located in the galactic plane between the constellations of Sagittarius, Scutum, and Serpentine. They said it lit relatively brightly, but they were unable to identify it based on Maxi’s data.
It wasn’t long before other astronomers piled in. Using the Neil Geirels Swift Observatory, a space telescope, astrophysicist Jimmy Kenya of Pennsylvania State University and colleagues mapped the site to confirm the discovery with an independent instrument, locating it.
Swift saw the object in x-rays, but not optical or ultraviolet light, at the location identified by MAXI’s observations.
“This site is not located at the site of any known X-ray source, so we agree that this is a new transient source MAXI J1816-195,” they wrote in A notification has been sent to ATel.
“In addition, Swift/XRT’s archival observations of this area, taken on June 22, 2017, do not reveal any point source at this location.”
Curious and curious.
next was neutron star Internal Configuration Explorer (Nice), a NASA X-ray instrument also installed on the International Space Station, in an investigation led by astrophysicist Peter Bolt of NASA’s Goddard Space Flight Center.
And this is where things start to get really interesting. NICER captured X-ray pulses at 528.6 Hz – indicating that the object is spinning at a rate of 528.6 times per second – as well as an X-ray thermonuclear explosion.
This disclosure they wrote“shows that MAXI J1816-195 is a neutron star and a new millisecond X-ray pulsar.”
So what does that mean? Well, not everything pulsars Both are built. At the most basic level, a pulsar is a type of neutron star, which is the collapsed core of a dead massive star that has morphed into a supernova. These objects are very small and very dense — about 2.2 times the mass of the Sun, packed into a ball 20 kilometers (12 miles) or so across.
In order for a neutron star to be classified as a pulsar, it must…a pulsar. Beams of radiation emit from its poles; Because of the star’s angle method, these beams sweep the earth like beams from a lighthouse. Millisecond pulsars are pulsars that rotate very quickly pulsating hundreds of times per second.
Some pulsars are only powered by rotation, but others are powered by accretion. The neutron star is located in a binary system with another star, and its orbit is so close that material from the companion star is drawn into the neutron star. This material is directed along the neutron star’s magnetic field lines to its poles, where it falls to the surface, creating hotspots that glow brightly in X-rays.
In some cases, the accretion process can spin around the pulsar to millisecond rotation speeds. This is an X-ray accumulating pulsar in milliseconds, and MAXI J1816-195 appears to belong to this rare category.
The thermonuclear X-ray burst detected by NICER is likely the result of unstable thermonuclear combustion of material accreted by the companion star.
Because the discovery is so new, observations at multiple wavelengths are ongoing. Already follow up Using SwiftThe Liverpool 2-meter telescope was used on the Canary island of La Palma in Spain Looking for an optical analog?, although nothing was discovered. Other astronomers are also encouraged to board the MAXI J1816-195 train.
Meanwhile, a full analysis of the pulsar’s timing is underway, and it will be generalized, Bolt and his team said, as more data becomes available. You can follow along ATel.
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