"Kepler" discovered a strange supernova: quickly caught fire, quickly went out

Source: UpCosmos.com

In spite of the fact that the system of orientation in the Kepler telescope space runs out of fuel , the device continues to work. Usually, a telescope records the passage of exoplanets over the disk of its star, but it is also capable of recording events like supernova explosions. The other day it became known about the next discovery, which was made with the help of Kepler: astronomers discovered a very unusual supernova that behaved quite differently from its “relatives”.

Initially, the supernova in question was not assigned to a specific class. The problem is that it ignited very quickly and disappeared at least quickly - about eight times faster than usual. The information conveyed by the telescope, the authors of the discovery passed on to colleagues, so that other experts could do an analysis of the situation.

The event in question received the identifier KSN 2015K. Data about this object has already fallen into the hands of scientists, but no one has ever classified it as a system located at the initial stage of the development of a supernova. The flash itself was as bright as the other flashes appearing during the supernova explosion. But all this happened under a somewhat accelerated scenario.

KSN 2015K reached peak brightness in just a couple of days. Then, during the week, the “supernova” gradually faded out, and after three weeks the object completely disappeared. For comparison - another supernova reached its maximum brightness in two weeks, not days. As mentioned above, KSN 2015K scored a maximum brightness eight times faster than a “regular” supernova, if this adjective applies to supernovae.

The process of the appearance of a “fast supernova”, if it is, of course, a supernova, got its own name, FELT (fast evolving luminous transient).


Previously, FELTs were recorded with telescopes, but very rarely and in a random order, since it is impossible to predict their appearance in a certain part of the sky. Accordingly, it was impossible to study the stages of the evolution of “fast supernovae” due to their scarcity. But the information provided by the Kepler telescope of a different kind - although it “spotted” the flash in a random order, but thanks to the periodicity of observations of the same sky (every half hour), scientists were able to trace the stages of development of KSN 2015K.

Presumably, such a fast supernova, a representative of the new Kilon class, appears when two neutron stars or a neutron star merge with a black hole. In some cases, a very big star turns into a “kilon” one. True, these stars are still unknown to astronomers - the star should be truly gigantic. It may well be that the explosion of Eta Kiel, which occurred in the 1800s, is just kilon. Then for several days it was the brightest star in the sky of the Earth. After the explosion, the star left behind a huge gas and dust cloud.

The term “kilon” was suggested by Brian Metzger in 2010. It is designed to show that the energy emitted by an object can be about 1000 times greater than the energy emitted by ordinary new ones. Kilon, among other things, is also a powerful source of gravitational waves and strong electromagnetic radiation. There is an assumption that kilon - the main supplier of elements heavier than iron.

Kilon's first observations occurred in 2013 thanks to the Hubble telescope. Then he was able to register a short gamma-ray burst 130603B. Kilon's gravity waves were first recorded on August 17, 2017 by the LIGO and Virgo observatories (GW170817). In the same sky region, the Fermi Space Telescopes (GLAST Fermi) and INTEGRAL registered gamma radiation (GRB 170817A, SSS17a). Kilon appeared in the galaxy NGC 4993 in the constellation Hydra. Scientists observed a flash for several weeks, build a light curve, get spectra, find out what elements were formed during the explosion.

To date, the exact reason for the appearance of kilon unknowns, and even more so, such "fast" as the object KSN 2015K, there are only assumptions, as mentioned above. Scientists continue to analyze the information obtained, so that other discoveries can wait for us. The results of the study object was published in the publication Nature Astronomy.

DOI: 10.1038 / s41550-018-0423-2