Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
---|---|
Constellation | Microscopium |
Right ascension | 20h 41m 23.65766s [1] |
Declination | −31° 35′ 53.8334″ [1] |
Apparent magnitude (V) | 5.74 [2] (5.75 - 5.76) [3] |
Characteristics | |
Evolutionary stage | AGB [4] |
Spectral type | M1 III [5] or M0 III [6] |
B−V color index | +1.53 [7] |
Variable type | suspected [8] |
Astrometry | |
Radial velocity (Rv) | −97.3±2.3 [9] km/s |
Proper motion (μ) | RA: +109.914 mas/yr [1] Dec.: −60.256 mas/yr [1] |
Parallax (π) | 7.6563 ± 0.0891 mas [1] |
Distance | 426 ± 5 ly (131 ± 2 pc) |
Absolute magnitude (MV) | +0.04 [10] |
Details | |
Mass | 1.27 [11] M☉ |
Radius | 44.2±2.2 [12] R☉ |
Luminosity | 620+45 −20 [1] L☉ |
Surface gravity (log g) | 1.40 [11] cgs |
Temperature | 3,908±122 [13] K |
Metallicity [Fe/H] | −0.28 [11] dex |
Other designations | |
Database references | |
SIMBAD | data |
HD 196917 (HR 7909; 17 G. Microscopii; NSV 25227) is a solitary star [16] located in the southern constellation Microscopium. It is faintly visible to the naked eye as a red-hued point of light with an apparent magnitude of 5.74. [2] Gaia DR3 parallax measurements imply a distance of 426 light-years and [1] it is rapidly approaching the Solar System with a heliocentric radial velocity of −97.3 km/s . [9] At its current distance, HD 196917's brightness is diminished by 0.13 magnitudes due to interstellar extinction [17] and it has an absolute magnitude of +0.04. [10]
HD 196917 has a stellar classification of either M1 III [5] or M0 III, [6] indicating that it is an evolved M-type giant. It is currently on the asymptotic giant branch, [4] fusing hydrogen and helium shells around an inert carbon core. It has 1.27 times the mass of the Sun [11] but it has expanded to 44.2 times the radius of the Sun. [12] It radiates 620 times the luminosity of the Sun [1] from its enlarged photosphere at an effective temperature of 3,908 K . [13] HD 196917 is metal deficient with an iron abundance of [Fe/H] = −0.28 or 52.5% of the Sun's. [11]
The variability of the star was first detected in 1997 by the Hipparcos mission. [18] It found variations between 5.82 and 5.86 in the Hipparcos passband. Koen & Lyer (2002) observed visual variations from the star and found that HD 196917 varies by 0.009 magnitudes within 21.01 hours. [19] As of 2004, its variability has not been confirmed. [20]
NO Apodis is a solitary, red hued variable star located in the southern circumpolar constellation Apus. It has an average apparent magnitude of 5.86, allowing it to be faintly seen with the naked eye. The object is relatively far at a distance of 790 light years but is drifting closer with a heliocentric radial velocity −18.3 km/s.
HD 27245, also known as HR 1335 or rarely 25 H. Camelopardalis is a solitary red-hued star located in the northern circumpolar constellation Camelopardalis. It has an apparent magnitude of 5.4, making it faintly visible to the naked eye. Gaia DR3 Parallax measurements place it approximately 607 light years away from it the Solar System and is drifting further away with a heliocentric radial velocity of 25.2 km/s. At its current distance, HD 27245's brightness is diminished by 0.36 magnitudes due to extinction from interstellar dust. It has an absolute magnitude of −0.27.
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.
S Apodis, also known as HD 133444 is a variable star located in the southern circumpolar constellation Apus. It has an apparent magnitude ranging from 9.6 to 17, which is below the limit for naked eye visibility. The object is located relatively far at a distance of approximately 15,000 light years based on Gaia DR3 parallax measurements, but it is drifting closer with a heliocentric radial velocity of −75 km/s.
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 57197, also known as M Puppis or HR 2789, is a suspected astrometric binary located in the southern constellation Puppis, the poop deck. It has an apparent magnitude of 5.84, making it faintly visible to the naked eye under ideal conditions. Based on parallax measurements from the Gaia satellite, the system is estimated to be 629 light years away from the Solar System. The value is poorly constrained, but it appears to be receding with a heliocentric radial velocity of 13 km/s. At its current distance, HD 57197's brightness is diminished by 0.3 magnitudes due to interstellar dust. It has an absolute magnitude of -0.43.
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 1032 is a solitary star in the southern circumpolar constellation Octans. It is faintly visible to the naked eye with an apparent magnitude of 5.77 and is estimated to be 850 light years away from the Solar System based on parallax measure. However, it is receding with a heliocentric radial velocity of 4 km/s.
HD 37289, also known as HR 1916, is a solitary, orange hued star located in the northern circumpolar constellation Camelopardalis. It has an apparent magnitude of 5.61, 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 308 light years distant. It appears to be approaching the Sun, having a heliocentric radial velocity of −20.7 km/s.
WZ Columbae, also known as HD 38170, is a solitary, bluish-white hued star located in the southern constellation Columba, the dove. It has an apparent magnitude of 5.28, allowing it to be faintly visible to the naked eye. Based on parallax measurements from the Gaia spacecraft, the object is about 365 light years distant. It appears to be receding from the Solar System, having a heliocentric radial velocity of 36.3 km/s.
AF Columbae, also known as HD 42682, is a solitary, red hued variable star located in the southern constellation Columba, the dove. It has an apparent magnitude that fluctuates between 5.6 and 5.71. Nevertheless, it is faintly visible to the naked eye. Parallax measurements from the Gaia spacecraft place the star relatively far at a distance of 820 light years. However, it is approaching the Solar System with a poorly constrained radial velocity of −19 km/s.
HD 34255, also known HR 1720, is a star located in the northern circumpolar constellation Camelopardalis, the giraffe. It has an apparent magnitude of 5.60, allowing it to be faintly visible to the naked eye. The object is located relatively far at a distance of about 1.65 kly but is approaching the Solar System with a heliocentric radial velocity of −7.7 km/s.
HD 115088, also known as HIP 64951, is a star located in the southern circumpolar constellation Chamaeleon. It has an apparent magnitude of 6.33, placing it near the limit for naked eye visibility. Based on parallax measurements from the Gaia spacecraft, the object is estimated to be 412 light years distant. At that distance, its brightness is diminished by 0.37 magnitudes due to interstellar dust.
HD 40091, also known as HR 2082, is a solitary star located in the southern constellation Columba, the dove. It has an apparent magnitude of 5.54, 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 501 light years distant. However, it is rapidly receding with a high heliocentric radial velocity of 114 km/s.
HD 197630, also known as HR 7933 or rarely 23 G. Microscopii, is a probable astrometric binary located in the southern constellation Microscopium. The visible component is a bluish-white hued star that is faintly visible to the naked eye with an apparent magnitude of 5.47. Based on parallax measurements from the Gaia satellite, the system is estimated to be 328 light years away. However, it is drifting closer with a heliocentric radial velocity of −30 km/s. At its current distance, HD 197630's brightness is diminished by 0.11 magnitudes due to interstellar dust. A 2012 multiplicity survey failed to confirm the velocity variations.
HD 187086, also known as HR 7537, is a probable astrometric binary located in the southern constellation Telescopium. It has an average apparent magnitude of 5.9, making it faintly visible to the naked eye. The star is located relatively far at a distance of 1,020 light years based on Gaia DR3 parallax measurements but is rapidly drifting closer with a heliocentric radial velocity of −64 km/s. At its current distance, HD 187086's brightness is diminished by 0.27 magnitudes due to interstellar dust. It has an absolute magnitude of −0.8.
V718 Coronae Australis is a solitary variable star located in the southern constellation Corona Australis. It is faintly visible to the naked eye as a red-hued point of light with an apparent magnitude of 5.43. Gaia DR3 parallax measurements imply a distance of 630 light years and it is currently receding with a heliocentric radial velocity of 28.5 km/s. At its current distance V718 CrA's brightness is diminished by 0.37 magnitudes due to interstellar dust and it has an absolute magnitude of −1.03.
HD 193002 is a solitary red hued star located in the southern constellation Telescopium. It has an apparent magnitude of 6.26, placing it near the limit for naked eye visibility, even under ideal conditions. The object is located relatively far at a distance of 1,030 light years based on Gaia DR3 parallax measurements, but it is approaching the Solar System with a heliocentric radial velocity of −9.1 km/s. At its current distance, HD 193002's brightness is diminished by 0.17 magnitudes due to interstellar dust and it has an absolute magnitude of −0.93.
HD 170521, also known as HR 6937 or rarely 12 G. Coronae Australis, is a solitary star located in the southern constellation Corona Australis. It is faintly visible to the naked eye as an orange-hued point of light with an apparent magnitude of 5.69. The object is located relatively far at a distance of approximately 1,500 light years based on Gaia DR3 parallax measurements, and it is receding with a heliocentric radial velocity of 7.2 km/s. At its current distance, HD 170521's brightness is heavily diminished by 0.46 magnitudes due to extinction from interstellar dust and it has an absolute magnitude of −1.90.
HD 23523 is a binary star located in the northern circumpolar constellation Camelopardalis. It has a combined apparent magnitude of 5.82, making it faintly visible to the naked eye under ideal conditions. When resolved, the primary has an apparent magnitude of 6.31 while the secondary has a magntiude of 7.11. The system is located relatively close at a distance of about 234 light-years based on Gaia DR3 parallax measurements and it currently drifting closer with a somewhat heliocentric radial velocity of −9.6 km/s. At its current distance, HD 23523's combined brightness is diminished by 0.16 magnitudes due to interstellar extinction and it has a combined absolute magnitude of +1.55.