Rho Ophiuchi (ρ Ophiuchi) is a multiple star system in the constellation Ophiuchus. The central system has an apparent magnitude of 4.63.=10.5px  Based on the central system's parallax of 9.03 mas, it is located about 360 light-years (110 parsecs) away. The other stars in the system are slightly farther away.

The central pair is known as Rho Ophiuchi AB. 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 sky-projected distance between the two stars appears to be 3.1″, corresponding to a separation of at least 344 astronomical units (au). However, the actual separation is larger, and the two take about 2,400 years to complete an orbit. The two stars dominate the radiation field around the Rho Ophiuchi cloud complex.

Rho Ophiuchi A emits X-rays, and exhibits strong variability in emission over periods of about 1.2 days, corresponding to its rotation period. The exact origin of its X-ray variability is unknown: it could be an magnetically active spot on its surface, or it could be a small low-mass companion. Related to this is its extremely strong magnetic field; its dipole strength is at (least Bd = 1.9 ± 0.2 kG.(Wikipedia)