Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Corona Australis |
Right ascension | 18h 13m 59.67590s [1] |
Declination | –42° 34′ 31.3558″ [1] |
Apparent magnitude (V) | +9.33 [2] |
Characteristics | |
Spectral type | K0IV/V [3] |
B−V color index | 0.861±0.032 [2] |
Astrometry | |
Radial velocity (Rv) | −17.51±0.20 [1] km/s |
Proper motion (μ) |
RA: +36.061
mas/
yr
[1] Dec.: –80.180 mas/ yr [1] |
Parallax (π) | 22.0344 ± 0.0177 mas [1] |
Distance | 148.0 ± 0.1
ly (45.38 ± 0.04 pc) |
Absolute magnitude (MV) | 6.20 [2] |
Details [4] | |
Mass | 0.81±0.02 M☉ |
Radius | 0.80+0.01 −0.02 [5] R☉ |
Luminosity | 0.388±0.001 [5] L☉ |
Surface gravity (log g) | 4.43±0.08 cgs |
Temperature | 5,101+50 −41 [5] K |
Metallicity [Fe/H] | −0.09±0.03 dex |
Age | 4.0±3.8 Gyr |
Other designations | |
Database references | |
SIMBAD | data |
Exoplanet Archive | data |
HD 166724 is a star in the southern constellation of Corona Australis. It is invisible to the naked eye with an apparent visual magnitude of +9.33. [2] The star is located at a distance of 148 light-years (45 parsecs) from the Sun based on parallax, but is drifting closer with a radial velocity of −18 km/s. [1] It is predicted to come as close as 97.0 light-years in around 1.2 million years from now. [2] The star has an absolute magnitude of 6.20. [2]
The stellar classification of HD 166724 is K0IV/V, [3] showing blended features of a K-type main-sequence star with a more evolved subgiant star. It is slightly active with chromospheric activity being demonstrated by an emission peak in the Ca II K absorption line. [4] The age of the star is poorly constrained, but it is spinning slowly with a period of around 30 days. [4] It has 81% of the mass of the Sun and 80% [4] of the Sun's girth. The star is radiating 39% [5] of the luminosity of the Sun from its photosphere at an effective temperature of 5,101 K. [4]
From 1998 to 2012, the star was under observance from the CORALIE echelle spectrograph at La Silla Observatory. In 2012, a long-period, wide-orbiting exoplanet was deduced by radial velocity variations. This was published in November. The discoverers noted that HD 166724 b is among "the three most eccentric planets with a period larger than 5 years" alongside HD 98649 b and HD 219077 b; but unlike them, too dim as a candidate for direct imaging with current technology. The reason for this high orbital eccentricity is unknown. [4] In 2023, the inclination and true mass of HD 166724 b were determined via astrometry. [7]
Companion (in order from star) |
Mass |
Semimajor axis ( AU) |
Orbital period ( years) |
Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b | 3.8+0.65 −0.29 MJ |
5.17+0.38 −0.49 |
13.0+1.4 −1.8 |
0.729+0.018 −0.017 |
68+15 −16 or 112+16 −15 ° |
— |
Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Corona Australis |
Right ascension | 18h 13m 59.67590s [1] |
Declination | –42° 34′ 31.3558″ [1] |
Apparent magnitude (V) | +9.33 [2] |
Characteristics | |
Spectral type | K0IV/V [3] |
B−V color index | 0.861±0.032 [2] |
Astrometry | |
Radial velocity (Rv) | −17.51±0.20 [1] km/s |
Proper motion (μ) |
RA: +36.061
mas/
yr
[1] Dec.: –80.180 mas/ yr [1] |
Parallax (π) | 22.0344 ± 0.0177 mas [1] |
Distance | 148.0 ± 0.1
ly (45.38 ± 0.04 pc) |
Absolute magnitude (MV) | 6.20 [2] |
Details [4] | |
Mass | 0.81±0.02 M☉ |
Radius | 0.80+0.01 −0.02 [5] R☉ |
Luminosity | 0.388±0.001 [5] L☉ |
Surface gravity (log g) | 4.43±0.08 cgs |
Temperature | 5,101+50 −41 [5] K |
Metallicity [Fe/H] | −0.09±0.03 dex |
Age | 4.0±3.8 Gyr |
Other designations | |
Database references | |
SIMBAD | data |
Exoplanet Archive | data |
HD 166724 is a star in the southern constellation of Corona Australis. It is invisible to the naked eye with an apparent visual magnitude of +9.33. [2] The star is located at a distance of 148 light-years (45 parsecs) from the Sun based on parallax, but is drifting closer with a radial velocity of −18 km/s. [1] It is predicted to come as close as 97.0 light-years in around 1.2 million years from now. [2] The star has an absolute magnitude of 6.20. [2]
The stellar classification of HD 166724 is K0IV/V, [3] showing blended features of a K-type main-sequence star with a more evolved subgiant star. It is slightly active with chromospheric activity being demonstrated by an emission peak in the Ca II K absorption line. [4] The age of the star is poorly constrained, but it is spinning slowly with a period of around 30 days. [4] It has 81% of the mass of the Sun and 80% [4] of the Sun's girth. The star is radiating 39% [5] of the luminosity of the Sun from its photosphere at an effective temperature of 5,101 K. [4]
From 1998 to 2012, the star was under observance from the CORALIE echelle spectrograph at La Silla Observatory. In 2012, a long-period, wide-orbiting exoplanet was deduced by radial velocity variations. This was published in November. The discoverers noted that HD 166724 b is among "the three most eccentric planets with a period larger than 5 years" alongside HD 98649 b and HD 219077 b; but unlike them, too dim as a candidate for direct imaging with current technology. The reason for this high orbital eccentricity is unknown. [4] In 2023, the inclination and true mass of HD 166724 b were determined via astrometry. [7]
Companion (in order from star) |
Mass |
Semimajor axis ( AU) |
Orbital period ( years) |
Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b | 3.8+0.65 −0.29 MJ |
5.17+0.38 −0.49 |
13.0+1.4 −1.8 |
0.729+0.018 −0.017 |
68+15 −16 or 112+16 −15 ° |
— |