On August 23, 2017, astronomers have unveiled a photo that is the most detailed ever image of a star other than our Sun. The image of the red “supergiant” Antares has been constructed using the European Southern Observatory’s (ESO) Very Large Telescope Interferometer (VLTI) on Cerro Paranal (a mountain in the Atacama Desert of northern Chile).
The Very Large Telescope Interferometer (VLTI) consists of the coherent combination of the four VLT Unit Telescopes (8.2 meters in diameter) or the four moveable 1.8-meter Auxiliary Telescopes. It is used to resolve small objects. The VLTI provides milli-arcsec angular resolution at low and intermediate (R=12,000) spectral resolution at near-infrared wavelengths.
Due to its characteristics, the VLTI has become a very attractive means for scientific research on various objects like young pre-main sequence stars and their protoplanetary disks, post-main-sequence mass-losing stars, binary objects and their orbits, solar system asteroids, and extragalactic objects such as active galactic nuclei.
Located around 620 light-years from the Sun, Antares, also known as Alpha Scorpii is the fifteenth-brightest star in the night sky; the brightest star in the constellation of Scorpius, and is often referred to as “the heart of the scorpion”.
It is a red “supergiant”. Its exact size remains uncertain, but, probably with a radius that is approximately 1 billion 228 million kilometers (883 times that of the Sun), it is one of the largest stars in the Universe, and if placed in the center of the Solar System, its outer surface would lie between the orbits of Mars and Jupiter.
It is dwarfed by even larger red supergiants, such as VY Canis Majoris and UY Scuti, though.
Antares’ mass is calculated to be around 12 times that of the Sun.
Antares is also nearing the end of its life. Once there is no more fuel left to burn, the star will collapse and explode into a supernova, possibly in the next ten thousand years. After the explosion, the Antares supernova could be as bright as the full moon and be visible in the daytime for a few months.