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AsteriaStar
Red giant · Monoceros

28 Monocerotis

Knowledge graph28 MonHR 3141HD 65953HIP 39211

Scientific overview

28 Monocerotis is a red giant in the constellation Monoceros (Monocerotis), lying about 449.9 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 typeK4III
Luminosity classIII
Apparent magnitude4.69
Absolute magnitude-1.01
Luminosity (Sun = 1)220
Colour index (B−V)1.475
Distance449.9 ly (137.93 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 3083024286391515136 · elevated RUWE

Parallax7.8537 ± 0.1224 masSIMBAD · measured
Distance127.7 pcGaia · estimated
Proper motion (RA)66.335 mas/yrSIMBAD · measured
Proper motion (Dec)-75.314 mas/yrSIMBAD · measured
Radial velocity26.7 ± 0.8 km/sSIMBAD · measured
Spectral typeK4IIISIMBAD · catalogued
Right ascension (ICRS)120.3 degSIMBAD · measured
Declination (ICRS)-1.3926 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 3083024286391515136 · 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 · 2006AstL...32..759G · 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
  • 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
Monoceros
Hemisphere
Both (equatorial)
Best seen
Spring (N. evening sky)
RA / Dec
8.0204h / -1.3926°

Knowledge connections

  • In constellationMonoceros

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.