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AsteriaStar
Red giant · Sagittarius

HR 6766

Knowledge graphHR 6766HD 165634HIP 88839

Scientific overview

HR 6766 is a red giant in the constellation Sagittarius (Sagittarii), lying about 339 light-years from Earth.

Class K. Cooler orange stars. Long-lived and abundant; many are stable hosts for planets. Such stars have surface temperatures around 3,700–5,200 K and appear orange to the eye.

Physical properties

Spectral typeK0IIICNpvar
Luminosity classIII
Apparent magnitude4.55
Absolute magnitude-0.53
Luminosity (Sun = 1)142
Colour index (B−V)0.938
Distance339 ly (103.95 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 4050817990273288064

Parallax9.4718 ± 0.1821 masSIMBAD · measured
Distance105.4 pcGaia · estimated
Proper motion (RA)24.35 mas/yrSIMBAD · measured
Proper motion (Dec)-31.617 mas/yrSIMBAD · measured
Radial velocity-4.87 ± 0.1 km/sSIMBAD · measured
Spectral typeG7:IIIbCN-1CH-3.5HK+1SIMBAD · catalogued
Effective temperature5374.3 KGaia · modeled
Radius18.924 R_sunGaia · modeled
Surface gravity (log g)2.3995 log(cm/s^2)Gaia · modeled
Metallicity [M/H]-0.1049 dexGaia · modeled
Right ascension (ICRS)272 degSIMBAD · measured
Declination (ICRS)-28.4571 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 4050817990273288064 · 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 · 2002ApJS..141..503N · direct catalogue measurement · retrieved 2026-07-11
  • Spectral type: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · sp_type · 1989ApJS...71..245K · catalogue identifier/value · retrieved 2026-07-11
  • Effective temperature: ESA Gaia astrometric survey · Gaia DR3 · gaiadr3.astrophysical_parameters · teff_gspphot · row 4050817990273288064 · model output · retrieved 2026-07-11
  • Radius: ESA Gaia astrometric survey · Gaia DR3 · gaiadr3.astrophysical_parameters · radius_gspphot · row 4050817990273288064 · model output · retrieved 2026-07-11
  • Surface gravity (log g): ESA Gaia astrometric survey · Gaia DR3 · gaiadr3.astrophysical_parameters · logg_gspphot · row 4050817990273288064 · model output · retrieved 2026-07-11
  • Metallicity [M/H]: ESA Gaia astrometric survey · Gaia DR3 · gaiadr3.astrophysical_parameters · mh_gspphot · row 4050817990273288064 · 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 red giant is an evolved star that has exhausted core hydrogen and expanded enormously, cooling at its surface as it fuses heavier elements in shells.

Location in the sky

Constellation
Sagittarius
Hemisphere
Southern
Best seen
Summer (N. evening sky)
RA / Dec
18.1347h / -28.4571°

Knowledge connections

  • In constellationSagittarius

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.