Observation data Epoch J2000 [1] Equinox J2000 [1] | |
---|---|
Constellation | Hercules |
Right ascension | 17h 30m 16.42797s |
Declination | +47° 24′ 07.9010″ |
Apparent magnitude (V) | 7.305 [2] |
Characteristics | |
Spectral type | G9V Fe−0.8 [3] |
B−V color index | +0.830 [2] |
J−H color index | +0.338 [4] |
J−K color index | +0.412 [4] |
Astrometry | |
Radial velocity (Rv) | −83.980 ± 0.0008 [5] km/s |
Proper motion (μ) | RA: 169.814 [6] mas/yr Dec.: 77.133 [6] mas/yr |
Parallax (π) | 46.1856 ± 0.0042 mas [7] |
Distance | 70.619 ± 0.006 ly (21.652 ± 0.002 pc) |
Orbit [7] | |
Primary | HD 159062 A |
Companion | HD 159062 B |
Period (P) | 411+71 −70 yr |
Semi-major axis (a) | 2.860+0.320 −0.330" (61.9+7.0 −7.2 AU ) |
Eccentricity (e) | 0.102+0.11 −0.065 |
Inclination (i) | 63.0+1.8 −2.4° |
Longitude of the node (Ω) | 133.4+1.7 −1.3° |
Periastron epoch (T) | 2507000+16000 −31000 |
Argument of periastron (ω) (secondary) | 260+70 −76° |
Details [8] | |
HD 159062 A | |
Mass | 0.80±0.05 [7] M☉ |
Radius | 0.76±0.04 R☉ |
Surface gravity (log g) | 4.4±0.1 cgs |
Temperature | 5283±100 K |
Metallicity [Fe/H] | −0.31±0.06 dex |
Rotational velocity (v sin i) | 2.06±0.5 km/s |
Age | ~9–13 [9] Gyr |
HD 159062 B | |
Mass | 0.6083+0.0083 −0.0073 [7] M☉ |
Temperature | 4580+440 −160 K |
Age | cooling age: 8+3 −5 [9] Gyr |
Other designations | |
AG+47° 1251, BD+47° 2491, Gaia DR3 1362295082910131200, GC 23733, GJ 4010, HD 159062, HIP 85653, SAO 46762, PPM 56246, WDS J17303+4724A, LSPM J1730+4724, NLTT 44958, TIC 270258076, TYC 3513-1056-1, GSC 03513-01056, IRAS 17289+4726, 2MASS J17301639+4724078, WISEA J173016.61+472408.6, USNO-B1.0 1374-00341178 [1] | |
Database references | |
SIMBAD | HD 159062 |
HD 159062 is a spectroscopic binary [1] consisting of a Sun-like star and a white dwarf positioned in the northern constellation of Hercules. With an apparent magnitude of 7.305, it is too faint to be seen by the naked eye but is readily visible via binoculars. [10] It is located at a distance of 70.619 light-years (21.652 parsecs) according to parallax calculations, and is approaching the Solar System at a heliocentric radial velocity of −83.980 km/s.
The primary star, designated HD 159062 A, is a G-type main-sequence star slightly cooler than the Sun with 80% the mass and 76% the radius. It has the spectral type G9V Fe−0.8, where the "Fe−0.8" suffix indicates a slight but anomalous deficiency of metals like iron. [11] Indeed, it has a low metallicity of [Fe/H]=−0.31±0.06 dex. The star is thought to be ancient, somewhere between 9-13 billion years old, and has been marked as a population II star and a candidate blue straggler. [12] It rotates on its axis at roughly 2 km/s, about the same as the Sun's equatorial rotational velocity (1.997 km/s [13] ).
Based on stellar kinematics, it is very likely (88% probability) a part of the thick disk population, and has been measured to have a europium abundance typical of thick disk stars. However, it is highly enhanced in s-process elements, such as barium, lanthanum, and cerium. [14] Fuhrmann et al. (2017) noted that the barium overabundance is particularly extreme at [Ba/Fe]=0.40 dex, which they argued was almost certainly the result of stellar wind accretion from a distant (orbital period 10-1,000 years) former asymptotic giant branch primary, which would have shriveled up into a cool white dwarf companion. [15]
As predicted, a white dwarf, HD 159062 B, was discovered in 2019 by Hirsch et al. [8] in a near-circular orbit around HD 159062 A at a distance of approximately 62 AU with a period of 411 years. The low eccentricity and large separation of the orbit implies that a Roche lobe overflow never took place. [7] It was once a ~1.5 M☉ star, whose lifespan came to an end roughly 8 billion years ago and has been radiating away heat as a stellar remnant ever since. [9] It has now cooled to an effective temperature of 4,580 K (4,310 °C; 7,780 °F). Its mass, together with its orbital parameters, was determined precisely using a Python script devised in 2021. [7]
Alpha Caeli is the brightest star in the constellation Caelum. It is in fact a binary star, made up of a F-type star of magnitude 4.46 and a red dwarf of magnitude 12.5. They are separated by 6.6" in the sky. Parallax measurements by the Gaia spacecraft imply a distance of 20.4 pc (67 ly) to Alpha Caeli. A debris disk has been detected around the primary component of the system.
HD 178911 is a triple star system with an exoplanetary companion in the northern constellation of Lyra. With a combined apparent visual magnitude of 6.70, it is a challenge to view with the naked eye. The system is located at a distance of approximately 161 light years from the Sun based on parallax measurements, but is drifting closer with a radial velocity of −38 km/s.
HD 115404 is a binary star system located in the constellation Coma Berenices. Parallax measurements made by Hipparcos put the system at 36 light-years, or 11 parsecs, away. The combined apparent magnitude of the system is 6.52, with the magnitudes of the components being 6.66 and 9.50.
Gliese 433 is a dim red dwarf star with multiple exoplanetary companions, located in the equatorial constellation of Hydra. The system is located at a distance of 29.6 light-years from the Sun based on parallax measurements, and it is receding with a radial velocity of +18 km/s. Based on its motion through space, this is an old disk star. It is too faint to be viewed with the naked eye, having an apparent visual magnitude of 9.81 and an absolute magnitude of 10.07.
HD 202628 is a single star in the southern constellation of Microscopium. It has an apparent visual magnitude of +6.7, which makes it too faint to be readily visible to the naked eye. The star is located at a distance of 77.7 light years from the Sun based on parallax, and it is drifting further away with a radial velocity of +12.1 km/s. The absolute magnitude of this star is 4.86.
ADS 7251 is a binary star system 6.33 parsecs from the Sun. The components are near-identical red dwarfs separated by 17″ in 2019.
HD 90132 is a solitary white hued star located in the southern constellation Antlia. It has an apparent magnitude of 5.33, making it one of the brighter members of this generally faint constellation. The star is relatively close at a distance of 135 light years but is receding with a heliocentric radial velocity of 17 km/s.
HD 168009 is a star in the northern constellation of Lyra. It has an apparent visual magnitude of 6.3, placing it just above to below the normal limit of stars visible to the naked eye under good viewing conditions of 6-6.5. An annual parallax shift of 42.93 mas provides a distance estimate of 76 light years. It is moving closer to the Sun with a heliocentric radial velocity of −65 km/s. In about 328,000 years from now, the star will make its closest approach at a distance of around 17 ly (5.1 pc).
HD 111395 is a single, variable star in the northern constellation of Coma Berenices. It has the variable star designation LW Com, short for LW Comae Berenices; HD 111395 is the Henry Draper Catalogue designation. The star has a yellow hue and is just bright enough to be barely visible to the naked eye with an apparent visual magnitude that fluctuates around 6.29. Based upon parallax measurements, it is located at a distance of 55.8 light years from the Sun. The star is drifting closer with a radial velocity of −8.9 km/s. It is a member of the Eta Chamaeleontis stellar kinematic group.
The Tucana-Horologium association (Tuc-Hor), or Tucana Horologium moving group, is a stellar association with an age of 45 ± 4 Myr and it is one of the largest stellar associations within 100 parsecs. The association has a similar size to the Beta Pictoris moving group (BPMG) and contains, like BPMG, more than 12 stars with spectral type B, A and F. The association is named after two southern constellations, the constellation Tucana and the constellation Horologium.
HD 164509 is a binary star system in the constellation of Ophiuchus. The primary component has an orbiting exoplanet companion. This system is located at a distance of 175 light years based on parallax measurements, and is drifting further away with a radial velocity of 13.7 km/s. It has an absolute magnitude of 4.64, but at that distance the system has an apparent visual magnitude of 8.10, which is too faint to be seen with the naked eye.
HR 4098, also known as HD 90508, is a binary star system in the northern constellation of Ursa Major at a distance of 75 light years. This object is barely visible to the naked eye as a dim, yellow star with an apparent visual magnitude of 6.45. It is approaching the Earth with a heliocentric radial velocity of 7.2±0.2 km/s.
HD 27022, also known as HR 1327, is a star located in the northern circumpolar constellation Camelopardalis. The object has also been designated as 20 H. Camelopardalis, but is not commonly used in modern times. It has an apparent magnitude of 5.27, allowing it to be faintly visible to the naked eye. Based on parallax measurements from Gaia DR3, the star has been estimated to be 347 light years away. It appears to be approaching the Solar System, having a heliocentric radial velocity of −19.5 km/s.
HD 193472 is a solitary star in the equatorial constellation Delphinus. It has an apparent magnitude of 5.94, making it visible with the naked eye if viewed under ideal conditions. Parallax measurements put it at a distance of 282 light years and has a radial velocity of −8 km/s, indicating that the object drifting towards the Solar System.
HD 72945 and HD 72946 form a co-moving star system in the northern constellation of Cancer. HD 72945 is a binary star that is dimly visible to the naked eye as a point of light with an apparent visual magnitude of 5.91. At an angular separation of 10.10″ is the fainter companion star HD 72946 at magnitude 7.25. It is being orbited by a brown dwarf. The system as a whole is located at a distance of approximately 84 light years from the Sun based on parallax measurements.
HD 222806 is a suspected astrometric binary in the southern circumpolar constellation Octans. It has an apparent magnitude of 5.74, allowing it to be faintly seen with the naked eye. Parallax measurements place the system at a distance of 565 light years and it is currently receding with a heliocentric radial velocity of 21 km/s.
HD 194012 is a star in the equatorial constellation Delphinus. It has an apparent magnitude of 6.15, making it visible to the naked eye under ideal conditions. The star is relatively close at a distance of only 85 light years but is receding with a heliocentric radial velocity of 4.5 km/s.
HD 221420 is a likely binary star system in the southern circumpolar constellation Octans. It has an apparent magnitude of 5.81, allowing it to be faintly seen with the naked eye. The object is relatively close at a distance of 102 light years but is receding with a heliocentric radial velocity of 26.5 km/s.
HR 8526, also known as HD 212168, is the primary of a triple star located in the southern circumpolar constellation Octans. The star and its companion have apparent magnitudes of 6.12 and 9.36 respectively. The system is located relatively close at a distance of 76 light years based on Gaia DR3 parallax measurements, but is receding with a heliocentric radial velocity of 15 km/s.
HD 127334 is a solitary Sun-like star in the northern constellation of Boötes. With an apparent magnitude of 6.36, it can be faintly seen by the naked eye from Earth as a yellow-hued dot of light. As such, it is listed in the Bright Star Catalogue as HR 5423. It is located at a distance of 76.29 light-years according to Gaia EDR3 parallax measurements.