Rho Coronae Borealis

ρ Coronae Borealis

Location of ρ Coronae Borealis (circled)
Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Corona Borealis
Right ascension	16h 01m 02.662s[1]
Declination	+33° 18′ 12.63″[1]
Apparent magnitude (V)	5.4[2]
Characteristics
Spectral type	G0V[3]
B−V color index	0.61
Astrometry
Radial velocity (Rv)	18.4 km/s
Proper motion (μ)	RA: −196.63±0.24[1] mas/yr Dec.: −773.02±0.21[1] mas/yr
Parallax (π)	58.02 ± 0.28[1] mas
Distance	56.2 ± 0.3 ly (17.24 ± 0.08 pc)
Absolute magnitude (MV)	+4.21[2]
Details
Mass	0.91[3] M☉
Radius	1.3617±0.0262[3] R☉
Luminosity	1.7059±0.0423[3] L☉
Surface gravity (log g)	4.12[2] cgs
Temperature	5627±54[3] K
Metallicity [Fe/H]	−0.24 (± 0.08)[2] dex
Rotation	20.3 ± 1.8 d[4]
Rotational velocity (v sin i)	1.0[2] km/s
Age	10.2[2] Gyr
Other designations
15 CrB, 2MASS J16010264+3318124, BD+33°2663, CCDM J16011+3318A, GC 21527, GJ 9537, HD 143761, HIP 78459, HR 5968, LTT 14764, ρ CrB, SAO 65024
Database references
SIMBAD	data

Rho Coronae Borealis (ρ CrB, ρ Coronae Borealis) is a yellow dwarf star approximately 57 light-years away in the constellation of Corona Borealis. The star is thought to be similar to the Sun with nearly the same mass, radius, and luminosity. It is orbited by two known exoplanets.^[5]

Stellar properties[]

Rho Coronae Borealis is a yellow main sequence star of the spectral type G0V. The star is thought to have 91 percent of the Sun's mass, along with 1.4 times its radius and 1.7 times its luminosity. It may only be 51 to 65 percent as enriched with elements heavier than hydrogen (based on its abundance of iron) and is likely somewhat older than the Sun at around ten billion years old.

The rotation period of Rho Coronae Borealis is approximately 20 days, even though at this age, stars are hypothesized to decouple their rotational evolution and magnetic activity.^[4]

Planetary system[]

An extrasolar planet in a 39.8-day orbit around Rho Coronae Borealis was discovered in 1997 by observing the star's radial velocity variations.^[6] This detection method only gives a lower limit on the true mass of the companion. In 2001, preliminary Hipparcos astrometric satellite data indicated that the orbital inclination of the star's companion was 0.5°, nearly face-on, implying that its mass was as much as 115 times Jupiter's.^[7] A paper published in 2011 supported this claim using a new reduction of the astrometric data, with an updated mass value of 169.7 times Jupiter, with a 3σ confidence region 100.1 to 199.6 Jupiter masses.^[8] Such a massive body would be a dim red dwarf star, not a planet. In 2016, however, a paper was published that used interferometry to rule out any stellar companions to this star, in addition to detecting a second planetary companion in a 102-day orbit.^[5]