Nova exploded as fast as a flash was discovered by astronomers

US astronomers have discovered one strange star who created it fastest Nova type explosion that has never been observed. A bright nova usually loses its luster after a few weeks or even months, but this particular nova named V1674 Hercules, which became visible in the constellation of Hercules on June 12, 2021, while it was so bright that it could be seen even with the naked eye. , after just one day had almost disappeared, as if someone had only lit a flash for a while.

Researchers at the Universities of Arizona, Minnesota and Ohio, who published the study in the Journal of the American Astronomical Society, said they were surprised. As astrophysics professor Summer Starfield of Arizona put it, “it only lasted about a day. The previous fastest nova was one we had studied in 1991, the V838 Herculis, which had faded after two to three days.

Nova are sudden bursts of bright light from a two-star system. Each nova is created by a white dwarf star (that is, the very dense remnant of the core of a small-medium star) and its accompanying star, as the former attracts matter from the latter. The white dwarf raises the temperature of this material, causing an uncontrollable reaction that releases large amounts of electromagnetic energy. The explosion throws away matter with great speed and the whole phenomenon is perceived by the Earth as very bright.

Launched materials are recycled into the universe, ending up creating new stellar systems. Sometimes the white dwarf does not lose all its material during a nova, but gradually increases its mass, becomes more unstable and eventually explodes as a type 1a supernova, one of the brightest phenomena in the universe.

Lightning bolts are very rare. In addition, in this case of the V1674 Hercules, in addition to its very short duration, another unusual feature is that the light and energy it emits, vibrates like the sound of a bell. One year after the explosion, every 501 seconds such a vibration continues to be recorded in both the visible light and X-rays, for reasons that are mysterious.

Another team of astronomers, led by researchers at MIT, announced at a conference of the American Astronomical Society in California that they have discovered a new planetary system in our “neighborhood” just 33 light-years from Earth. At its center is a small, relatively cold, dwarf M-type star called HD 260655, around which at least two Earth-sized exoplanets move.

It is estimated that these are rocky worlds that probably do not have hospitable living conditions, as they are close enough to their star and receive a lot of radiation and heat, so it is unlikely to have liquid water on their surface. However, the proximity of the system makes it another target for further study of the possible atmosphere of its planets.

The system was initially detected by the US Transiting Exoplanet Survey Satellite (TESS) and later confirmed by ground-based telescopes in Hawaii and Spain. Astronomers consider it possible that there are other planets in the same system, which they may find in the future.

Based on the data collected so far, one exoplanet of the star, HD 260655b, is 1.2 times larger than Earth and takes 2.8 days to orbit its star, while the second planet HD 260655c , is 1.5 times larger than the Earth and its orbit lasts 5.7 days. In terms of mass, the first exoplanet is about twice that of Earth, while the second is three times as large. In terms of density, the former is slightly denser than the Earth, while the latter is somewhat less dense.