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Star · Cygnus

Phi Cygni

Knowledge graphPhi Cyg12 CygHR 7478HD 185734

Scientific overview

Phi Cygni is a star in the constellation Cygnus (Cygni), lying about 266.25 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 typeG8III-IV...
Luminosity classIII
Apparent magnitude4.68
Absolute magnitude0.12
Luminosity (Sun = 1)77.911
Colour index (B−V)0.971
Distance266.25 ly (81.63 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 2032457178261396736

Parallax12.7786 ± 0.1207 masSIMBAD · measured
Distance78.0352 pcGaia · estimated
Proper motion (RA)1.52 mas/yrSIMBAD · measured
Proper motion (Dec)35.883 mas/yrSIMBAD · measured
Radial velocity4.5 ± 0.02 km/sSIMBAD · measured
Spectral typeG8III-IVSIMBAD · catalogued
Effective temperature5032.1 KGaia · modeled
Radius12.9647 R_sunGaia · modeled
Surface gravity (log g)2.6472 log(cm/s^2)Gaia · modeled
Metallicity [M/H]-0.0693 dexGaia · modeled
Right ascension (ICRS)294.8 degSIMBAD · measured
Declination (ICRS)30.1533 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 2032457178261396736 · 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 · 2004A&A...424..727P · direct catalogue measurement · retrieved 2026-07-11
  • Spectral type: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · sp_type · 1952ApJ...116..122R · catalogue identifier/value · retrieved 2026-07-11
  • Effective temperature: ESA Gaia astrometric survey · Gaia DR3 · gaiadr3.astrophysical_parameters · teff_gspphot · row 2032457178261396736 · model output · retrieved 2026-07-11
  • Radius: ESA Gaia astrometric survey · Gaia DR3 · gaiadr3.astrophysical_parameters · radius_gspphot · row 2032457178261396736 · model output · retrieved 2026-07-11
  • Surface gravity (log g): ESA Gaia astrometric survey · Gaia DR3 · gaiadr3.astrophysical_parameters · logg_gspphot · row 2032457178261396736 · model output · retrieved 2026-07-11
  • Metallicity [M/H]: ESA Gaia astrometric survey · Gaia DR3 · gaiadr3.astrophysical_parameters · mh_gspphot · row 2032457178261396736 · 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.

Location in the sky

Constellation
Cygnus
Hemisphere
Northern
Best seen
Summer (N. evening sky)
RA / Dec
19.6563h / 30.1533°

Knowledge connections

  • In constellationCygnus

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.