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Sunday, May 13, 2018

Astronomers found a pair of dead stars that can be placed between the Earth and the Moon


Astronomers using the NICER telescope found in the group of the Altar a pair of dead stars that could easily be placed between the Earth and the Moon. White dwarf and pulsar are located at a distance of 300 thousand kilometers from each other. The findings of the researchers were published in the journal Astrophysical Journal Letters.


The NICER telescope was put into orbit and installed at the International Space Station last year. Its main task is to search for pulsars and study their structure by the way X-ray flashes appear on the surface of pulsars at the time when they begin to "steal" matter from their neighbors.

In the course of the study, scientists observed the double star IGR J17062-6143, which was discovered in 2006. It is a relatively unusual pair of white dwarf and pulsar, stealing the matter of a neighbor and periodically generating unusually long and frequent X-ray flares.

Astronomers long ago knew that the "halves" of IGR J17062-6143 are very close to each other, but they could not calculate the distance between them because of insufficiently long observations and the absence of telescopes capable of very accurately measuring the length of "dips" in the x-ray signal , generated by the rotation of the pulsar.

The launch of NICER solved this problem, and in the autumn of last year NASA astronomers for the first time were able to accurately measure both the rotation frequency of the pulsar, and the distance between it and its companion, watching IGR J17062-6143 for five days. As it turned out, they are separated only 300 thousand kilometers, a scant distance by the standards of space.

Due to this, the white dwarf makes one revolution around the pulsar in just 38 minutes, moving at the same time with a huge speed, close to light. The pulsar moves in a similar way, but its movement is difficult to notice, since it is two orders of magnitude heavier than the dwarf.

Read also: Astronomers first discovered helium in the atmosphere of an exoplanet
Earlier it was reported that  scientists discovered the brightest supernova in the universe . ASASSN-15lh is twice as bright as the previously fixed maximum for supernovae, thousands of times brighter than the "normal" supernovae and 50 times brighter than our Milky Way galaxy.

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