Astronomers discover a mysterious dust-emitting object orbiting a binary star
(Brian P. Powell et al. / ArXiv, 2021)
Astronomers have discovered irregular periodic drops in the brightness of one of the stars in the TIC 400799224 binary system
The darkness cannot be explained by the eclipse of a star by another star or planet.
According to scientists, such a phenomenon may arise due to the sporadically emerging dense cloud of dust, which is generated by one or more large bodies.
If you follow the change in the brightness of the star for a long time, in some cases it is possible to reveal periodic small drops in brightness caused by the passage of the planet along the disk of the star.
This method of detecting exoplanets is called transit and is widely used in practice, the most famous telescopes looking for transits are Kepler and TESS.
Along with the vast number of exoplanets discovered, their observations have led to the discovery of a number of phenomena such as supernova shockwaves, exo-comets, decaying planets, unusual multiple star systems, and the famous Tabby's star.
Despite the fact that Kepler completed its work discoveries of unusual variable sources of radiation are still taking place.
A group of astronomers led by Brian P. Powell of the Goddard Space Flight Center reported the discovery of an unusual object around one of the stars in the widely separated binary system TIC 400799224.
TIC 400799224 brightness variations of TESS observation data.
(Brian P. Powell et al. / ArXiv, 2021)
It initially caught the attention of scientists when reanalyzing the TESS data archive using neural network.
After that, the researchers turned to observational data from the ASAS-SN system, Evryscope, LCOGT and other ground-based telescopes.
Changes in the brightness of a star in the TIC 400799224 system occur with a period of 19.77 days, but they are variable in shape, depth of brightness dip, and duration.
The strongest drop in brightness lasted about two days and had a depth of about 25%.
However, given that there are two stars in the system, the actual depth of an eclipse of a star can be up to 37% or 75% of the initial level.
Scientists have noticed that the behavior of TIC 400799224 resembles the ones of systems where the destruction of planets or planetesimals with the formation of dust was observed.
If we assume that in the case under consideration there is a micron-sized source of dust, then it should generate dust grains at a rate of 3×1012 grams per second (or about 5 solar masses per billion years).
If the asteroid Ceres, with a radius of 500 kilometers, was destroyed at such a speed, then it would be enough for eight thousand years.
The researchers believe that a body can move around the star in its orbit, sporadically emitting a cloud of dust and debris, with a total mass of about 1019 grams
The other option is a collision of large bodies occurs in the system, which also leads to the formation of dust.
To pinpoint the nature of the eclipses in TIC 400799224, scientists will need new observations that can be made with small telescopes.
They also need to determine which of the two stars that make up TIC 400799224 is the true host star of the eclipsing object.
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