Astronomer Gennady Borisov from Crimea in at the end of summer 2019 opened an alien comet originating from another planetary system. Now it is officially recognized, and soon comet Borisov will approach the Earth. The Center for Small Planets has officially confirmed the opening of comet C/2019 Q4 (Borisov) by astronomer Borisov. Less than a year ago, other astronomers discovered the first interstellar asteroid. Both events indicate a high frequency of objects from other systems in the vicinity of the Sun.
A freshly discovered comet by the end of 2019 should approach the Earth at a distance of up to 150 million kilometers, which will allow observing its behavior in detail. The comet may reach the seventeenth-star value, that is, it will be relatively bright in the Earth"s sky. The object flies so fast that the gravity of the Sun is not able to hold it, so starting in 2020, the comet will begin to move away and in thousands of years will leave the solar system. The discovery is announced in a circular letter from the Centre for Small Planets.
An unprecedented orbit
The opening of the first interstellar comet was officially recognized!
Comet C/2019 Q4 (Borisov) is named after its discoverer. Borisov works as an engineer at the station, and astronomy is a hobby for him. However, he has achieved great success in it: before 2019 he opened seven "ordinary" comets and about three dozen asteroids. On August 30, 2019, an amateur astronomer, with the help of a small 65-centimeter telescope that he had once assembled on his own, traced a new object with very unusual parameters. First, its speed relative to the Sun was 30. 5 kilometers per second. Secondly, as the following observations, including other astronomers, have shown, it has an extremely unusual orbit - its eccentricity is more than three. Until now, all the bodies discovered in the Solar System had eccentricity much less, less than 1. 2.
Eccentricity is a numerical characteristic that shows the degree of deviation of the so-called conical section from the circle. In the case of celestial bodies at eccentricity equal to zero the orbit is completely circular - it has no deviations from the circle. When it is greater than zero, but less than one, the orbit is ellipsoidal, i. e. it resembles an oval, and the higher the eccentricity, the more this oval is stretched out.
At a value of eccentricity from one and above the orbit ceases to be closed and becomes parabolic at first (eccentricity equal to one), and then hyperbolic. When eccentricity is equal to infinity, the orbit turns into a straight line. From this, it is obvious that anybody with an eccentricity of orbit above one leaves the Solar system. However, if its speed is lower than 16. 4 kilometers per second, i. e. the third cosmic speed, its body will not be able to leave: the gravity of the Sun will slow down the body, and the eccentricity of its trajectory will begin to fall until it falls below one. Before Borisov"s discovery, only two bodies with eccentricity were known to have been known to be more than one. The first was the comet C/1980 E1 (Bowell), discovered in 1980, which had an eccentricity of 1, 057. However, it was quite common for a comet from the solar system.
Astronomers watched her get more than one eccentricity in the eighties, due to the impulse she received from the gravity maneuver near Jupiter. Then the gravity of the vast planet gave the comet speed above 23 kilometers per second and slightly changed its trajectory, which allowed the object to begin leaving the solar system. The second object with an eccentricity of more than one orbit - 1. 20 to be exact - was the asteroid 1I/Oumouamois, discovered in 2018.
Analysis of its orbit showed that it was born outside the solar system and simply flies through it at a speed of 26. 33 kilometers per second. This is how this object became the first known interstellar asteroid. Comet C/2019 Q4 (Borisov) differs from 1I/Oumouamois in that its speed is noticeably higher and it also has a coma tail indicating the active emission of comet gases. Also, it has an eccentricity above three, which is much higher than that of any previously known body.
The comet is carried through our system with a rather moderate deviation from the straight path - "through". Because of these unusual parameters, the Center for Small Planets, located in the U. S., has long enough to check the observations of the new body by various telescopes around the world to make sure that its extremely exotic parameters of the trajectory are not a mistake observation and reality. Finally, on September 12, 2019, he officially recognized the discovery.