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AsteriaStar
Yellow dwarf · Centaurus

Uklun

Knowledge graphHD 102117HIP 57291

Scientific overview

Uklun is a yellow dwarf in the constellation Centaurus (Centauri), lying about 129.48 light-years from Earth.

Class G. Yellow stars like the Sun. On the main sequence they steadily fuse hydrogen into helium. Such stars have surface temperatures around 5,200–6,000 K and appear yellow to the eye.

Physical properties

Spectral typeG6V
Luminosity classV
Apparent magnitude7.47
Absolute magnitude4.48
Luminosity (Sun = 1)1.411
Colour index (B−V)0.721
Distance129.48 ly (39.7 pc)

Values are real catalogue data; fields without a reliable value are omitted, never estimated.

Precision measurements

Astrometry and astrophysics from SIMBAD and Gaia DR3 · Gaia DR3 5341673851394297600

Parallax25.3531 ± 0.0178 masSIMBAD · measured
Distance39.4209 pcGaia · estimated
Proper motion (RA)-63.574 mas/yrSIMBAD · measured
Proper motion (Dec)-70.331 mas/yrSIMBAD · measured
Radial velocity49.525 ± 3.000e-4 km/sSIMBAD · measured
Spectral typeG6VSIMBAD · catalogued
Effective temperature5534.4 KGaia · modeled
Radius1.2799 R_sunGaia · modeled
Surface gravity (log g)4.1945 log(cm/s^2)Gaia · modeled
Metallicity [M/H]0.1355 dexGaia · modeled
Right ascension (ICRS)176.2 degSIMBAD · measured
Declination (ICRS)-58.7037 degSIMBAD · measured
Full field-level provenance
  • Parallax: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · plx_value · 2020yCat.1350....0G · direct catalogue measurement · retrieved 2026-07-11
  • Distance: ESA Gaia astrometric survey · Gaia EDR3 · Bailer-Jones (2021) · external.gaiaedr3_distance · r_med_geo · row 5341673851394297600 · Bayesian estimate · retrieved 2026-07-11
  • Proper motion (RA): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · pmra · 2020yCat.1350....0G · direct catalogue measurement · retrieved 2026-07-11
  • Proper motion (Dec): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · pmdec · 2020yCat.1350....0G · direct catalogue measurement · retrieved 2026-07-11
  • Radial velocity: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · rvz_radvel · 2018A&A...616A...7S · direct catalogue measurement · retrieved 2026-07-11
  • Spectral type: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · sp_type · 1975MSS...C01....0H · catalogue identifier/value · retrieved 2026-07-11
  • Effective temperature: ESA Gaia astrometric survey · Gaia DR3 · gaiadr3.astrophysical_parameters · teff_gspphot · row 5341673851394297600 · model output · retrieved 2026-07-11
  • Radius: ESA Gaia astrometric survey · Gaia DR3 · gaiadr3.astrophysical_parameters · radius_gspphot · row 5341673851394297600 · model output · retrieved 2026-07-11
  • Surface gravity (log g): ESA Gaia astrometric survey · Gaia DR3 · gaiadr3.astrophysical_parameters · logg_gspphot · row 5341673851394297600 · model output · retrieved 2026-07-11
  • Metallicity [M/H]: ESA Gaia astrometric survey · Gaia DR3 · gaiadr3.astrophysical_parameters · mh_gspphot · row 5341673851394297600 · model output · retrieved 2026-07-11
  • Right ascension (ICRS): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · ra · 2020yCat.1350....0G · direct catalogue measurement · retrieved 2026-07-11
  • Declination (ICRS): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · dec · 2020yCat.1350....0G · direct catalogue measurement · retrieved 2026-07-11

measured = direct catalogue value · estimated = Bayesian inference (Bailer-Jones distance) · modeled = model output (Gaia GSP-Phot). Fields a source did not provide are omitted, never invented.

Evolution

A yellow dwarf is a G-type main-sequence star like the Sun. After about ten billion years it will swell into a red giant and finally leave behind a white dwarf.

Location in the sky

Constellation
Centaurus
Hemisphere
Southern
Best seen
Spring (N. evening sky)
RA / Dec
11.7474h / -58.7037°

Knowledge connections

  • In constellationCentaurus
  • Orbited byHD 102117 b

Sources

The primary and reference sources this topic draws on.

  • HYG DatabaseHYG Database (Hipparcos + Yale Bright Star + Gliese), by D. Nash / astronexus

    Aggregated, openly-licensed star catalogue combining Hipparcos, the Yale Bright Star Catalogue, and the Gliese Catalogue of Nearby Stars.

  • HipparcosESA Hipparcos space astrometry mission

    High-precision parallax, magnitude, and position for ~118,000 stars.