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AsteriaStar
Blue giant · Pegasus

Markab

Alpha Pegasi

Knowledge graphAlpha Peg54 PegHR 8781HD 218045

Scientific overview

Markab is a blue giant in the constellation Pegasus (Pegasi), lying about 133.34 light-years from Earth.

Class B. Hot, blue-white stars. Massive and luminous, they often light up the regions where they form. Such stars have surface temperatures around 10,000–30,000 K and appear blue-white to the eye.

Physical properties

Spectral typeB9.5III
Luminosity classIII
Apparent magnitude2.49
Absolute magnitude-0.57
Luminosity (Sun = 1)147
Colour index (B−V)-0.002
Distance133.34 ly (40.88 pc)

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

Precision measurements

Astrometry and astrophysics from SIMBAD

Parallax24.46 ± 0.19 masSIMBAD · measured
Proper motion (RA)60.4 mas/yrSIMBAD · measured
Proper motion (Dec)-41.3 mas/yrSIMBAD · measured
Radial velocity-2.7 ± 0.8 km/sSIMBAD · measured
Spectral typeA0IVSIMBAD · catalogued
Right ascension (ICRS)346.2 degSIMBAD · measured
Declination (ICRS)15.2053 degSIMBAD · measured
Full field-level provenance
  • Parallax: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · plx_value · 2007A&A...474..653V · direct catalogue measurement · retrieved 2026-07-11
  • Proper motion (RA): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · pmra · 2007A&A...474..653V · direct catalogue measurement · retrieved 2026-07-11
  • Proper motion (Dec): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · pmdec · 2007A&A...474..653V · direct catalogue measurement · retrieved 2026-07-11
  • Radial velocity: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · rvz_radvel · 2006AstL...32..759G · direct catalogue measurement · retrieved 2026-07-11
  • Spectral type: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · sp_type · 1995ApJS...99..135A · catalogue identifier/value · retrieved 2026-07-11
  • Right ascension (ICRS): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · ra · 2007A&A...474..653V · direct catalogue measurement · retrieved 2026-07-11
  • Declination (ICRS): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · dec · 2007A&A...474..653V · 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 blue giant is a hot, massive, highly luminous star that has evolved off the main sequence. Such stars are short-lived on cosmic timescales.

Location in the sky

Constellation
Pegasus
Hemisphere
Northern
Best seen
Autumn (N. evening sky)
RA / Dec
23.0793h / 15.2053°

Knowledge connections

  • In constellationPegasus

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.