Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
---|---|
Constellation | Apus |
Right ascension | 17h 57m 41.686s [1] |
Declination | −76° 10′ 40.62″ [1] |
Apparent magnitude (V) | 6.07±0.01 [2] |
Characteristics | |
Evolutionary stage | red giant branch [3] |
Spectral type | K2 III [4] |
U−B color index | +1.28 [5] |
B−V color index | +1.20 [5] |
Astrometry | |
Radial velocity (Rv) | +36.8±0.4 [6] km/s |
Proper motion (μ) | RA: +2.464 mas/yr [1] Dec.: −1.867 mas/yr [1] |
Parallax (π) | 5.2546 ± 0.022 mas [1] |
Distance | 621 ± 3 ly (190.3 ± 0.8 pc) |
Absolute magnitude (MV) | −0.26 [7] |
Details | |
Mass | 3.05 [8] M☉ |
Radius | 20.8 [9] R☉ |
Luminosity | 185 [10] L☉ |
Surface gravity (log g) | 2.04±0.02 [3] cgs |
Temperature | 4,498 [10] K |
Metallicity [Fe/H] | −0.13 [11] dex |
Rotational velocity (v sin i) | 2.1±1.3 [12] km/s |
Other designations | |
Database references | |
SIMBAD | data |
HD 161988, also known as HR 6635, is a solitary, orange hued star located in the southern circumpolar constellation Apus. It has an apparent magnitude of 6.07, [2] allowing it to be faintly visible to the naked eye. Parallax measurements place it at a distance of 621 light years, [1] and it is currently receding with a heliocentric radial velocity of 36.8 km/s . [6]
The object has a stellar classification of K2 III, [4] indicating that it is a red giant. Gaia Data Release 3 models place it on the red giant branch. At present it has 3.05 times the mass of the Sun [8] and an enlarged radius of 20.8 R☉ . [9] It shines at 185 times the luminosity of the Sun from its photosphere at an effective temperature of 4,498 K . [10] HD 161988 has an iron abundance 74% that of the Sun, [11] making it slightly metal deficient. Like most giants, it spins modestly with a projected rotational velocity of 2.1 km/s . [12]
HD 161988 has a 14th magnitude optical companion located 26.4 arcseconds away along a position angle of 122°. [15]
HD 92589 is a double star in the constellation Antlia. The system has a combined apparent magnitude of 6.39, placing it near the limit of naked eye visibility. The system is located about 590 light years away based on its parallax shift and has a heliocentric radial velocity of 11 km/s. This indicates that it is drifting away from the Solar System.
HD 165259, also known as HR 6751 is a triple star system located in the southern circumpolar constellation of Apus. It has an apparent magnitude of 5.86, making it faintly visible to the naked eye Parallax measurements place the system at a distance of 138 light years, and it is currently receding with a heliocentric radial velocity of 13.1 km/s.
HD 30442 is a solitary star in the northern circumpolar constellation Camelopardalis. It is faintly visible to the naked eye with an apparent magnitude of 5.47 and is estimated to be 403 light years away from the Solar System. The object has a heliocentric radial velocity of −37 km/s, indicating that it is drifting closer.
HD 63399 is an orange hued star located in the southern constellation Puppis, the poop deck. It has an apparent magnitude of 6.45, placing it near the limit for naked eye visibility. Based on parallax measurements from Gaia DR3, the object is estimated to be 445 light years distant. It appears to be receding with a spectroscopic radial velocity of 28.5 km/s. At its current distance, HD 63399 is diminished by 0.29 magnitudes due to interstellar dust.
Beta Microscopii, Latinized from β Microscopii, is a solitary star in the constellation Microscopium. It is close to the lower limit of stars that are visible to the naked eye having an apparent visual magnitude of 6.05 Based upon an annual parallax shift of 6.5022 mas as seen from Earth, this star is located 502 light years away from the Sun. At that distance, the visual magnitude is diminished by an extinction factor of 0.19 due to interstellar dust.
HD 126209, also known as HR 5389, is a solitary, orange hued star located in the southern circumpolar constellation Apus. It has an apparent magnitude of 6.06, making it faintly visible to the naked eye under ideal conditions. Based on parallax measurements from the Gaia spacecraft, the object is estimated to be 560 light years distant. It appears to be approaching the Solar System with a fairly constrained heliocentric radial velocity of −8.1 km/s. De Mederios et al. (2014) found the radial velocity to be variable, making it a probable spectroscopic binary. Eggen (1993) lists it as a member of the old disk population.
HD 121439, also known as HR 5240, is a solitary, bluish-white hued star located in the southern circumpolar constellation Apus. It has an apparent magnitude of 6.08, allowing it to be faintly visible to the naked eye. The object is located relatively far at a distance of 774 light years based on Gaia DR3 parallax measurements but is receding with a fairly constrained radial velocity of 4 km/s. At its current distance, HD 121439's brightness is diminished by 0.57 magnitudes due to interstellar dust.
HD 39901 is an orange hued star located in the constellation Columba. It is also called HR 2069, which is the star's Bright Star Catalog designation. Eggen (1989) lists it as a member of the old disk population.
HD 49268 is a solitary star in the southern circumpolar constellation Volans. It has an apparent magnitude of +6.49, placing it near the limit of naked eye visibility. Parallax measurements place the object at a distance of 456 light years; it is receding with a heliocentric radial velocity of 20.6 km/s.
HD 50002 is a solitary star in the southern circumpolar constellation Volans. It is faintly visible to the naked eye with an apparent magnitude of 6.09 and is located at a distance of 708 light years. However, it is drifting further with a heliocentric radial velocity of 5.1 km/s.
HD 64307, also known as HR 3075, is a solitary, orange hued star located in the northern circumpolar constellation Camelopardalis. It has an apparent magnitude of 5.35, allowing it to be faintly seen with the naked eye. Based on parallax measurements from the Gaia spacecraft, The object is estimated to be 690 light years distant. It appears to be receding from the Sun, having a heliocentric radial velocity of 34 km/s.
HD 80194 is a solitary star in the southern circumpolar constellation Chamaeleon. It has an apparent magnitude of 6.12, allowing it to be faintly seen with the naked eye. Parallax measurements place the object at a distance of 351 light years and is currently receding with a poorly constrained radial velocity of 0.9 km/s.
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 174387 is a solitary star in the southern constellation Telescopium. With an apparent magnitude of 5.49, it is faintly visible to the naked eye if viewed under dark skies. Parallax measurements put the object at a distance of 810 light years and it is currently approaching the Solar System with a heliocentric radial velocity of −28.1 km/s.
HD 170069 is a solitary star in the southern constellation Telescopium. It has an apparent magnitude of 5.68, allowing it to be faintly seen with the naked eye. The star is located at a distance of 590 light years but is approaching closer with a heliocentric radial velocity of −18 km/s. HD 170069 was designated as Tau Telescopii before Benjamin Apthorp Gould dropped the title.
HD 193721 is an astrometric binary in the southern circumpolar constellation Octans. It has an apparent magnitude of 5.77, allowing it to be faintly seen with the naked eye. Parallax measurements place the system 760 light years away from the Solar System and it is currently receding with a heliocentric radial velocity 8.6 km/s.
HD 182509, also designated as HR 7370, is an orange hued star located in the southern constellation Telescopium. It has an apparent magnitude of 5.69, making it faintly visible to the naked eye if viewed under ideal conditions. Parallax measurements place the object at a distance of 635 light years. It has a poorly constrained heliocentric radial velocity of −5 km/s, indicating that it is drifting towards the Solar System.
HD 208741, also known as HR 8380, is a yellowish-white hued star located in the southern circumpolar constellation Octans. It has an apparent magnitude of 5.91, making it faintly visible to the naked eye. Parallax measurements place it at a distance of 211 light years, and it is currently receding with a heliocentric radial velocity of 8 km/s.
HD 33519, also known as HR 1682, is a probable spectroscopic binary located in the southern circumpolar constellation Mensa. It is one of the stars near the limit of naked eye visibility, having an apparent magnitude of 6.28. The system is relatively far at a distance of 940 light years but is approaching with a heliocentric radial velocity of −2.5 km/s. However, this value is poorly constrained.
HD 31529, also known as HR 1584, is a solitary, orange hued star located in the southern constellation Caelum, the chisel. It has an apparent magnitude of 6.09, making it faintly visible to the naked eye if viewed under ideal conditions. This object is located relatively far at a distance of 932 light years based on parallax measurements from Gaia DR3, but is receding with a heliocentric radial velocity of 28.4 km/s. Eggen (1989) lists it as a member of the old disk population.