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Red supergiant · Sagitta

13 Sagittae

Knowledge graph13 SgeHR 7645HD 189577HIP 98438

Scientific overview

13 Sagittae is a red supergiant in the constellation Sagitta (Sagittae), lying about 1,019.2 light-years from Earth.

Class M. Cool red stars. The most common type in the galaxy, ranging from red dwarfs to red giants. Such stars have surface temperatures around 2,400–3,700 K and appear red to the eye.

Physical properties

Spectral typeM4IIIa
Luminosity classIa
Apparent magnitude5.33
Absolute magnitude-2.14
Luminosity (Sun = 1)627
Colour index (B−V)1.576
Distance1,019.2 ly (312.5 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 1820484908501127040 · elevated RUWE

Parallax3.4239 ± 0.1744 masSIMBAD · measured
Distance289.6 pcGaia · estimated
Proper motion (RA)1.272 mas/yrSIMBAD · measured
Proper motion (Dec)-13.365 mas/yrSIMBAD · measured
Radial velocity-17.56 ± 0.33 km/sSIMBAD · measured
Spectral typeM3/5IIISIMBAD · catalogued
Effective temperature3658.8 KGaia · modeled
Radius185.7 R_sunGaia · modeled
Surface gravity (log g)0.7053 log(cm/s^2)Gaia · modeled
Metallicity [M/H]0.6542 dexGaia · modeled
Right ascension (ICRS)300 degSIMBAD · measured
Declination (ICRS)17.5165 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 1820484908501127040 · 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 · 2005A&A...430..165F · direct catalogue measurement · retrieved 2026-07-11
  • Spectral type: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · sp_type · 1922ApJ....55...85L · catalogue identifier/value · retrieved 2026-07-11
  • Effective temperature: ESA Gaia astrometric survey · Gaia DR3 · gaiadr3.astrophysical_parameters · teff_gspphot · row 1820484908501127040 · model output · retrieved 2026-07-11
  • Radius: ESA Gaia astrometric survey · Gaia DR3 · gaiadr3.astrophysical_parameters · radius_gspphot · row 1820484908501127040 · model output · retrieved 2026-07-11
  • Surface gravity (log g): ESA Gaia astrometric survey · Gaia DR3 · gaiadr3.astrophysical_parameters · logg_gspphot · row 1820484908501127040 · model output · retrieved 2026-07-11
  • Metallicity [M/H]: ESA Gaia astrometric survey · Gaia DR3 · gaiadr3.astrophysical_parameters · mh_gspphot · row 1820484908501127040 · 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 supergiant is a colossal, cool, luminous evolved star. The largest known stars are red supergiants, and many end as supernovae.

Location in the sky

Constellation
Sagitta
Hemisphere
Northern
Best seen
Summer (N. evening sky)
RA / Dec
20.0009h / 17.5165°

Knowledge connections

  • In constellationSagitta

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.