Astronomer likely discovers second interstellar object

Amateur astronomer Gennady Borisov has discovered an object that probably originated outside our solar system. Based on initial observations, the suspected comet appears to be in a hyperbolic orbit and not orbiting the Sun.

Borisov announced his discovery at a Russian astronomy forum early this month. The astronomer discovered the object on August 30 from southern Crimea. He used a 650mm telescope and said multiple observations confirm that it is a real object. The strange job caught his eye. The comet was given the internal name gb00234, but has since been renamed C/2019 Q4 (Borisov) by the Minor Planet Center of the Harvard-Smithsonian Center for Astrophysics.

According to the Minor Planet Center, there are hyperbolic elements, which the institute says is a strong indication of interstellar origin. Several computers have also calculated the orbit, drawing the same conclusions. According to the organization, further observations are desirable because the current observations were made at a small angle between the sun and the object and at a low altitude on Earth. Partly because of this, it has yet to be definitively verified whether this is actually an interstellar visitor.

According to SkyandTelescope, the first images indicate the presence of a coma around the comet and a small tail, which would officially make it a comet. Comets contain quite a bit of ice. As a comet approaches the sun, the ice evaporates and forms a ring around the objects, forming the distinctive tail together with dust.

The object in question appears to be quite large and may have a diameter of 10 km. The comet is now probably 2.7au from the Sun. This means that the comet has a distance that is 2.7 times greater than the distance between the Earth and the Sun. If no unexpected disintegration occurs, the object could be visible for at least a year, according to the Minor Planet Center. Astronomy software developer Bill Gray, who was closely involved in the discovery, tells Forbes that the comet will remain in our solar system for six months. He points out that it is not yet clear how bright the comet will be.

Due to the long visit to our solar system and the moment of discovery, C/2019 Q4 (Borisov) is a lot more suitable to study than the first interstellar visitor, Oumuamua, which was discovered in October 2017. Because this comet had already left the sun, Mercury and Venus behind and was developing a high speed, it could only be followed for a short time and the object could hardly be studied, partly due to its inactivity. The comet discovered by Borisov is expected to reach its closest point to the sun on December 10. Oumuamua was not discovered until well past that point.