HD 27894

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Template:Short description

HD 27894
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Reticulum[1]
Right ascension Template:RA[2]
Declination Template:DEC[2]
Apparent magnitude (V) 9.36[1]
Characteristics
Spectral type K2 V[3]
U−B Template:Engvar +0.90[4]
B−V Template:Engvar +1.003±0.002[1]
Astrometry
Radial velocity (Rv)Script error: No such module "val".[5] km/s
Proper motion (μ) RA: Script error: No such module "val". mas/yr[2]
Dec.: Script error: No such module "val". mas/yr[2]
Parallax (π)22.8888±0.0121 mas[2]
DistanceTemplate:Rnd ± Template:Rnd ly
(Template:Rnd ± Template:Rnd pc)
Absolute magnitude (MV)6.225[6]
Details
Mass0.83±0.03[7] Template:Solar mass
Radius0.79±0.02[7] Template:Solar radius
Luminosity0.33±0.01[7] Template:Solar luminosity
Surface gravity (log g)4.56±0.03[7] cgs
Temperature4,923±32[7] K
Metallicity [Fe/H]+0.30±0.07[6] dex
Rotation44 days[6]
Rotational velocity (v sin i)≤ 1.5[6] km/s
Age7.7±2.3[8] Gyr
Metallicity [Fe/H]{{{metal_fe2}}} dex
Other designations
Template:Odlist[4]
Database references
SIMBADdata

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HD 27894 is a single star with a system of orbiting exoplanets, located in the southern constellation of Reticulum. It is too faint to be seen with the naked eye at an apparent visual magnitude of 9.36.[1] This system lies at a distance of 142.5 light years from the Sun, as determined via parallax measurements, and is drifting further away with a radial velocity of 83 km/s.[5]

The spectrum of HD 27894 presents as a K-type main-sequence star, an orange dwarf,[6] with a stellar classification of K2 V.[3] This is a quiescent solar-type star that displays no significant magnetic activity in its chromosphere[9] and is spinning slowly with a rotation period of roughly 44 days.[6] The abundance of iron in the star is much higher than in the Sun, an indicator that it is metal-rich.[6] It has 83% of the mass of the Sun and 79% of the Sun's radius. The star is radiating 33% of the luminosity of the Sun from its photosphere at an effective temperature of 4,923 K.[7]

Planetary system

In 2005, the Geneva Extrasolar Planet Search Team announced the discovery of an extrasolar planet orbiting the star.[6] In 2017, the discovery of two additional exoplanets was announced. One is very close to the star like the one discovered earlier, while the other one orbits the star at a much larger distance. It is the first system where such a large gap between orbital distances has been found.[9][10] In 2022, the inclination and true mass of HD 27894 d were measured via astrometry. The study only found strong evidence for planets b and d.[11]

Template:OrbitboxPlanet begin Template:OrbitboxPlanet Template:OrbitboxPlanet Template:OrbitboxPlanet

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See also

References

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  1. ↑ a b c d Script error: No such module "Citation/CS1".
  2. ↑ a b c d Template:Cite Gaia DR3
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  6. ↑ a b c d e f g h Script error: No such module "Citation/CS1".
  7. ↑ a b c d e f Script error: No such module "Citation/CS1".
  8. ↑ Script error: No such module "Citation/CS1".. See table 13.
  9. ↑ a b Script error: No such module "Citation/CS1".
  10. ↑ Script error: No such module "citation/CS1".
  11. ↑ Script error: No such module "Citation/CS1".

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Template:Sky Template:Stars of Reticulum

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