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AsteriaStar
Red giant · Aquarius

7 Aquarii

Knowledge graph7 AqrHR 8015HD 199345HIP 103401

Scientific overview

7 Aquarii is a red giant in the constellation Aquarius (Aquarii), lying about 546.3 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 typeK5III
Luminosity classIII
Apparent magnitude5.49
Absolute magnitude-0.63
Luminosity (Sun = 1)156
Colour index (B−V)1.474
Distance546.3 ly (167.5 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 6902502796794441600

Parallax5.0316 ± 0.1154 masSIMBAD · measured
Distance198.1 pcGaia · estimated
Proper motion (RA)-5.86 mas/yrSIMBAD · measured
Proper motion (Dec)-10.92 mas/yrSIMBAD · measured
Radial velocity-31.68 ± 0.12 km/sSIMBAD · measured
Spectral typeK4IIISIMBAD · catalogued
Effective temperature4016.1 KGaia · modeled
Radius45.3419 R_sunGaia · modeled
Surface gravity (log g)0.9938 log(cm/s^2)Gaia · modeled
Metallicity [M/H]-0.557 dexGaia · modeled
Right ascension (ICRS)314.2 degSIMBAD · measured
Declination (ICRS)-9.6975 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 6902502796794441600 · 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 · 2018yCat.1345....0G · direct catalogue measurement · retrieved 2026-07-11
  • Spectral type: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · sp_type · 1999MSS...C05....0H · catalogue identifier/value · retrieved 2026-07-11
  • Effective temperature: ESA Gaia astrometric survey · Gaia DR3 · gaiadr3.astrophysical_parameters · teff_gspphot · row 6902502796794441600 · model output · retrieved 2026-07-11
  • Radius: ESA Gaia astrometric survey · Gaia DR3 · gaiadr3.astrophysical_parameters · radius_gspphot · row 6902502796794441600 · model output · retrieved 2026-07-11
  • Surface gravity (log g): ESA Gaia astrometric survey · Gaia DR3 · gaiadr3.astrophysical_parameters · logg_gspphot · row 6902502796794441600 · model output · retrieved 2026-07-11
  • Metallicity [M/H]: ESA Gaia astrometric survey · Gaia DR3 · gaiadr3.astrophysical_parameters · mh_gspphot · row 6902502796794441600 · 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
Aquarius
Hemisphere
Both (equatorial)
Best seen
Summer (N. evening sky)
RA / Dec
20.9483h / -9.6975°

Knowledge connections

  • In constellationAquarius

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.