Article by: Andacs Robert Eugen, on 11 June 2022, at 10:45 am Los Angeles time

An element of a category of stars so rare that we can count on our fingers the known number of them, has just been discovered in the Milky Way. 

It is called MAXI J1816-195 and is at a distance of no more than 30,000 light-years from our planet. Preliminary observations and investigations suggest that it is a type of pulsar that so far has only 18 known specimens. 

Therefore, when their number is so small, any new object is an extremely interesting discovery, which can provide important statistical information about how these objects are formed, evolve, and behave. The X-ray light emitted by the object was first detected on June 7 by the Monitoring All-sky X-ray Image (MAXI) instrument of the Japanese Space Agency, mounted on the outside of the ISS.

In a post on The Astronomer's Telegram (ATel), a team led by astrophysicist Hitoshi Negoro of Nihon University in Japan said they had identified a previously uncatalogued X-ray source located in the galactic location between the constellations Sagittarius, Scutum, and Serpens. 

According to them, the object had a relatively strong brightness, but they failed to identify it based on MAXI data. It wasn't long before other astronomers began to join. Using the Neil Gehrels Swift Observatory, a high-performance telescope, astrophysicist Jamie Kennea of ​​Pennsylvania State University and his colleagues went to the location to confirm the detection with an independent instrument and locate the object. 

"This location is not in the location of any known X-ray source so far, so we agree that this is a new transient source MAXI J1816-195," they wrote in a notice posted on ATel. 

The next instrument to be observed was the Neutron Star Interior Composition Explorer (NICER), a NASA X-ray instrument also mounted on the ISS, in an investigation led by astrophysicist Peter Bult of the Goddard Space Flight Center at NASA. 

NICER detected 528.6 Hz X-ray pulses - suggesting that the object rotates 528.6 times per second - in the area of ​​an X-ray thermonuclear explosion companion. 

Because the discovery is so recent and surprising, observations with various tools are underway. Swift monitoring has already been carried out, and the 2 m Liverpool telescope on the Spanish island of La Palma in the Canary Islands has been used to search for an optical correspondent, although none have been detected so far. 

Other astronomers are also encouraged to get involved in "deciphering the secrets" of the MAXI J1816-195.