15 Eridani

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15 Eridani
Observation data
Epoch J2000        Equinox J2000
Constellation Eridanus
Right ascension 03h 18m 22.10504s [1]
Declination −22° 30 40.0191 [1]
Apparent magnitude  (V)4.875 [2]
(6.57 / 5.32) [3]
Characteristics
Evolutionary stage horizontal branch
Spectral type K0III [4]
B−V color index +0.90 [5]
Astrometry
Radial velocity (Rv)23.90±0.5 [6]  km/s
Proper motion (μ)RA: 13.08 [1]   mas/yr
Dec.: 13.33 [1]   mas/yr
Parallax (π)12.77 ± 1.17  mas [1]
Distance 260 ± 20  ly
(78 ± 7  pc)
Absolute magnitude  (MV)+0.85 [7]
Orbit [3]
Period (P)118.16 yr
Semi-major axis (a)0.340″
Eccentricity (e)0.030
Inclination (i)66.6°
Longitude of the node (Ω)271.6°
Periastron epoch (T)1934.24
Argument of periastron (ω)
(secondary)
333.5°
Details
15 Eri A
Mass 2.32 [8]   M
Luminosity 72.4 [8]   L
Temperature 4,960±31 [8]   K
Rotational velocity (v sin i)4.5±0.2 [7]  km/s
Age 1.44 [8]   Gyr
Other designations
15 Eri, CD−22°1146, HD  20610, HIP  15382, HR  994, SAO  168452, WDS J03184-2231
Database references
SIMBAD data

15 Eridani is a binary star [3] system in the equatorial constellation of Eridanus. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.875. [2] Based upon parallax measurements, the system is located around 260  light years away from the Sun. [1] It is moving further from the Earth with a heliocentric radial velocity of 24 km/s. [6]

This system has an orbital period of 118.16 years with an eccentricity of 0.030 and a semimajor axis of 0.340 . [3] The primary member, designated component A, is a magnitude 5.32 [9] giant star with a stellar classification of K0 III. [4] It is a red clump giant, [10] which means it is on the horizontal branch and is generating energy through helium fusion at its core. This star has 1.44 billion years old with 2.32 times the mass of the Sun. It is radiating 72.4 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4,960 K. [8] The companion, component B, has a magnitude of 6.57. [9]

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<span class="mw-page-title-main">Gamma Pyxidis</span> K-type giant star in the constellation Pyxis

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27 Hydrae is a triple star system system in the equatorial constellation of Hydra, located 222 light years away from the Sun. It is visible to the naked eye as a faint, orange-hued star with a combined apparent visual magnitude of 4.82. The system is moving further from the Earth with a heliocentric radial velocity of +25.6 km/s.

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<span class="mw-page-title-main">71 Ophiuchi</span> Giant star in the constellation of Ophiuchus

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<span class="mw-page-title-main">74 Ophiuchi</span> Star in the constellation Ophiuchus

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<span class="mw-page-title-main">19 Puppis</span> Binary star in the constellation Puppis

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<span class="mw-page-title-main">HD 27022</span> Star in the constellation Camelopardalis

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.

References

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