HR 4458

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Template:Short description

HR 4458
Observation data
Epoch J2000      Equinox J2000
Constellation Hydra[1]
A
Right ascension Template:RA[2]
Declination Template:DEC[2]
Apparent magnitude (V) 5.97[3]
B
Right ascension Template:RA[4]
Declination Template:DEC[4]
Apparent magnitude (V) 15[5]
Characteristics
Spectral type K0 V[6] + DC8[7]
U−B Template:Engvar 0.325[3]
B−V Template:Engvar 0.80[3]
V−R Template:Engvar 0.44Script error: No such module "Unsubst".
R−I Template:Engvar 0.40Script error: No such module "Unsubst".
Astrometry
A
Radial velocity (Rv)Script error: No such module "val".[2] km/s
Proper motion (μ) RA: –670.230 mas/yr[2]
Dec.: +822.399 mas/yr[2]
Parallax (π)104.6133±0.0277 mas[2]
DistanceTemplate:Rnd ± Template:Rnd ly
(Template:Rnd ± Template:Rnd pc)
Absolute magnitude (MV)6.05[8]
B
Proper motion (μ) RA: –701.802 mas/yr[4]
Dec.: +828.928 mas/yr[4]
Parallax (π)104.6570±0.0267 mas[4]
DistanceTemplate:Rnd ± Template:Rnd ly
(Template:Rnd ± Template:Rnd pc)
Absolute magnitude (MV)15[9]
Details
HR 4458 A
Mass0.87[2] Template:Solar mass
Radius0.84[10] Template:Solar radius
Luminosity (bolometric)0.368[11] Template:Solar luminosity
Surface gravity (log g)4.59[12] cgs
Temperature5,241[12] K
Metallicity [Fe/H]−0.37[12] dex
Rotational velocity (v sin i)6.79[13] km/s
Age4.6–5.8[14] Gyr
HR 4458 B
Mass0.58[15] Template:Solar mass
Luminosity (bolometric)0.000088[16] Template:Solar luminosity
Surface gravity (log g)8.12[17] cgs
Temperature5,000[15] K
Metallicity [Fe/H] dex
Age5.69[15]Template:Efn Gyr
Other designations
Template:Odlist[18]
B: Template:Odlist, VB 4
Database references
SIMBADA
B
ARICNSdata

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HR 4458 (HD 100623) is a binary star system 31.18 light-years away in the equatorial constellation of Hydra. It has the Flamsteed designation 20 Crateris[19] and the Gould designation 289 G. Hydrae;[20] the former refers to the constellation Crater, but when the IAU formally defined constellation boundaries, it was placed in Hydra. This object is visible to the naked eye as a dim, orange-hued star with an apparent visual magnitude of 5.97.[3] It is moving closer to the Earth with a heliocentric radial velocity of −22 km/s.[21]

The primary component is a K-type main-sequence star with a stellar classification of K0 V.[6] It is around five billion years old[14] with 84% of the Sun's radius.[10] The star is radiating 37% of the Sun's luminosity[11] from its photosphere at an effective temperature of 5,241 K.[12] It has been examined for the presence of an infrared excess, but none was detected.[11]

There is a 15th-magnitude common proper motion companion at an angular separation of Script error: No such module "val".,[7] corresponding to a projected separation of Script error: No such module "val"..[22] This is a white dwarf star with a classification of DC8.[7] The orbital period of the pair is estimated as Script error: No such module "convert"..[22]

Notes

Template:Notelist

References

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  1. ↑ Template:Cite constellation
  2. ↑ a b c d e f Template:Cite Gaia DR3
  3. ↑ a b c d Script error: No such module "Citation/CS1".
  4. ↑ a b c d Template:Cite Gaia DR3
  5. ↑ Script error: No such module "Citation/CS1".
  6. ↑ a b Script error: No such module "Citation/CS1".
  7. ↑ a b c Script error: No such module "Citation/CS1".
  8. ↑ Script error: No such module "Citation/CS1".
  9. ↑ Script error: No such module "Citation/CS1".
  10. ↑ a b Script error: No such module "Citation/CS1".
  11. ↑ a b c Script error: No such module "Citation/CS1".
  12. ↑ a b c d Script error: No such module "Citation/CS1".
  13. ↑ Script error: No such module "Citation/CS1".
  14. ↑ a b Script error: No such module "Citation/CS1".
  15. ↑ a b c Script error: No such module "Citation/CS1".
  16. ↑ Script error: No such module "Citation/CS1".
  17. ↑ Script error: No such module "Citation/CS1".
  18. ↑ Template:Cite simbad
  19. ↑ Script error: No such module "Citation/CS1".
  20. ↑ Script error: No such module "Citation/CS1".
  21. ↑ Script error: No such module "Citation/CS1".
  22. ↑ a b Script error: No such module "Citation/CS1".

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External links

  • Script error: No such module "citation/CS1".

Template:Stars of Hydra

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