Rho Ophiuchi - Antares region

2-panel mosaic of the Rho-Ophiuchi -Antares region, realised from 3 recent one-click observations with AUS-2.

The Antares – Rho Ophiuchi area is one of the most beautiful and colorful areas of the night sky and a favorite target for stargazers and astro-imagers.

It’s in the direct vicinity of the milky way core, at the heart of the constellation Scorpius.

Antares is one of the brightest stars in the sky, rising in the east in the north hemisphere spring, and can be observed all summer long.

The photogenic Antares – Rho Ophiuchi area consists of many interesting deep sky objects: emission nebulae, blue reflection nebulae, long dark (nebula) lanes, some globular clusters and (obviously) the multiple star system Rho Ophiuchi. In the second picture I identified most of these objects (using astrometry).

The Rho Ophiuchi cloud complex, is a nebula of gas and dust, which the Rho Ophiuchi system is embedded in. It is one of the easiest nearest star forming regions to observe: about 460 light-years away…

The central star system, known as Rho Ophiuchi AB, has an apparent magnitude of 4.63 and is located about 360 light-years away. It consists of at least two blue-colored subgiants or main-sequence stars, designated Rho Ophiuchi A and B, respectively. Rho Ophiuchi AB is a visual binary, and the two stars take about 2,400 years to complete an orbit.

The other stars in the system are slightly farther away. HIP 80474 is located 2.5 arcminutes away and is known as Rho Ophiuchi C. HIP 80461 is located 2.82 arcminutes away and is known as Rho Ophiuchi DE. Stars C and D are both B-type main-sequence stars, and D itself is another binary with an orbital period of around 680 years.