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AsteriaStar
Blue giant · Perseus

Delta Persei

Knowledge graphDelta Per39 PerHR 1122HD 22928

Scientific overview

Delta Persei is a blue giant in the constellation Perseus (Persei), lying about 516.1 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 typeB5III SB
Luminosity classIII
Apparent magnitude3.01
Absolute magnitude-2.99
Luminosity (Sun = 1)1,363
Colour index (B−V)-0.125
Distance516.1 ly (158.23 pc)

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

Precision measurements

Astrometry and astrophysics from SIMBAD

Parallax6.2435 ± 0.4991 masSIMBAD · measured
Proper motion (RA)29.038 mas/yrSIMBAD · measured
Proper motion (Dec)-23.365 mas/yrSIMBAD · measured
Radial velocity4 ± 3.7 km/sSIMBAD · measured
Spectral typeB5IIISIMBAD · catalogued
Right ascension (ICRS)55.7312 degSIMBAD · measured
Declination (ICRS)47.7875 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
  • 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 · 2007AN....328..889K · direct catalogue measurement · retrieved 2026-07-11
  • Spectral type: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · sp_type · catalogue identifier/value · 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 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
Perseus
Hemisphere
Northern
Best seen
Winter (N. evening sky)
RA / Dec
3.7154h / 47.7876°

Knowledge connections

  • In constellationPerseus (constellation)

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.