gjdonatiello
Rho Oph 2021
Rho Oph
Credit: Giuseppe Donatiello
Tair-3S 300mm f/4.5 + Canon EOS 4000D on Avalon M-zero Obs mount
Antares is a red supergiant M1.5 Iab variable star and the brightest star in Scorpius (mag +1.07). It is one of the largest known, with a radius approximately 680 times that of the Sun. Being in an advanced stage of evolution, with a current mass 15 times that of the Sun, it is destined to explode as a supernova within 100,000 years [The Perkins Catalog of Revised MK Types for the Cooler Stars].
It forms a binary system with a smaller, hotter companion, Antares B [A&A, 700, A36 (2025)] [MNRAS, Volume 529, Issue 4, April 2024, Pages 3630–3650].
Like all red supergiants, it is losing mass at a rapid rate and is producing a cloud of dust. This material is particularly evident in the mid-infrared, but the star's light is sufficient to produce scattering on neutral dust clouds. Scattering causes the "reflected" light to shift slightly to shorter wavelengths, which is why the cloud surrounding the star appears distinctly orange/yellow instead of red.
Galactic Environment
Antares is part of the Scorpius-Centaurus stellar association, one of the closest OB associations to Earth. This association is divided into three subgroups, and Antares belongs to the Superior Scorpius subgroup [John M. Carpenter et al 2025 ApJ 978 117].
NGC 6144 is a small globular cluster at 8.1 kpc (about 32,000 light-years) [The Astronomical Journal, Volume 119, Issue 4, pp. 1793-1802].
Taken from Piano Visitone (1420m), Pollino National Park, Italy in August 2021.
Rho Oph 2021
Rho Oph
Credit: Giuseppe Donatiello
Tair-3S 300mm f/4.5 + Canon EOS 4000D on Avalon M-zero Obs mount
Antares is a red supergiant M1.5 Iab variable star and the brightest star in Scorpius (mag +1.07). It is one of the largest known, with a radius approximately 680 times that of the Sun. Being in an advanced stage of evolution, with a current mass 15 times that of the Sun, it is destined to explode as a supernova within 100,000 years [The Perkins Catalog of Revised MK Types for the Cooler Stars].
It forms a binary system with a smaller, hotter companion, Antares B [A&A, 700, A36 (2025)] [MNRAS, Volume 529, Issue 4, April 2024, Pages 3630–3650].
Like all red supergiants, it is losing mass at a rapid rate and is producing a cloud of dust. This material is particularly evident in the mid-infrared, but the star's light is sufficient to produce scattering on neutral dust clouds. Scattering causes the "reflected" light to shift slightly to shorter wavelengths, which is why the cloud surrounding the star appears distinctly orange/yellow instead of red.
Galactic Environment
Antares is part of the Scorpius-Centaurus stellar association, one of the closest OB associations to Earth. This association is divided into three subgroups, and Antares belongs to the Superior Scorpius subgroup [John M. Carpenter et al 2025 ApJ 978 117].
NGC 6144 is a small globular cluster at 8.1 kpc (about 32,000 light-years) [The Astronomical Journal, Volume 119, Issue 4, pp. 1793-1802].
Taken from Piano Visitone (1420m), Pollino National Park, Italy in August 2021.