Astronomers from the University of Cambridge have discovered in our galaxy young star on the stage of formation. An article on this was published in the journal MNRAS.
A team of scientists in astronomy discovered in the universe a unique star-supergiant. It is reported that the star is not yet fully formed, but its mass exceeds the mass of the Sun is 30 times. In addition, it may increase when formed completely.
The observations were made with the help of X-ray space observatory Chandra, Swift, Fermi and NuSTAR (NASA), ground-based optical Southern African Large Telescope (SALT) and instruments of the European Southern Observatory in Chile (ESO).
X-ray source 2S 1553-542 known since 1975. Observations show that it is a neutron star in a binary system, which is accreting matter from a companion star. Circulation period of the binary system was evaluated at 30 days with a small, but the period of proper rotation of the neutron star is 9.3 seconds.
A new study led to a number of additional data. In particular, it became clear that the system is at a distance of about 20 kpc, or approximately 65 thousand. Light-years. The system is located on the far outskirts of the Milky Way, probably in the Sagittarius arm.
Scientists also managed to identify pulsar companion – a weak optical star class Be , observations that have confirmed that the system – one of the most distant X-ray binaries
space Observatory
These X-ray space observatory Chandra, Swift, Fermi and NuSTAR (NASA), the terrestrial optical South. – African Large Telescope (SALT) and infrared VVV survey, obtained by the instruments of the European Southern Observatory in Chile (ESO) have allowed scientists to refine the rotation period of the neutron star, which is 9.2788 seconds, and acceleration, as well as to measure the magnitude of its magnetic field. According to X-rays, researchers were able to determine the distance to the system – 16-24 kiloparsec (1 parsec – more than 30 trillion km), in other words, almost the opposite edge of the galaxy, in addition, they have established the coordinates of neutron star
Unexpected. find
the research part of the sky where this pulsar using SALT and infrared wavelengths have shown that next to it there are five stars, some of which are visible in the optics, and others only in the infrared. In order to understand which of these stars is actually a companion X-ray source 2S 1553-542, the researchers examined how these celestial bodies emit photons. It was found that the spectrum of a star very similar to the famous blue and white Class Be stars. Moreover, it showed signs that the star is surrounded by a disc of rotating material quickly. It is this star and was eventually companion pulsar.
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