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AsteriaStar
Subgiant · Hydrus

Beta Hydri

Knowledge graphBeta HyiHR 98HD 2151HIP 2021

Scientific overview

Beta Hydri is a subgiant in the constellation Hydrus (Hydri), lying about 24.33 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 typeG2IV
Luminosity classIV
Apparent magnitude2.82
Absolute magnitude3.46
Luminosity (Sun = 1)3.607
Colour index (B−V)0.618
Distance24.33 ly (7.46 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 4683897617110115200 · elevated RUWE

Parallax134.1 ± 0.11 masSIMBAD · measured
Distance7.4764 pcGaia · estimated
Proper motion (RA)2219.5 mas/yrSIMBAD · measured
Proper motion (Dec)324.1 mas/yrSIMBAD · measured
Radial velocity23.085 ± 3.000e-4 km/sSIMBAD · measured
Spectral typeG0VSIMBAD · catalogued
Right ascension (ICRS)6.4378 degSIMBAD · measured
Declination (ICRS)-77.2542 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
  • Distance: ESA Gaia astrometric survey · Gaia EDR3 · Bailer-Jones (2021) · external.gaiaedr3_distance · r_med_geo · row 4683897617110115200 · Bayesian estimate · 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 · 2018A&A...616A...7S · direct catalogue measurement · retrieved 2026-07-11
  • Spectral type: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · sp_type · 2006AJ....132..161G · 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 subgiant has begun to evolve off the main sequence, brightening and expanding as core hydrogen fusion ends.

Location in the sky

Constellation
Hydrus
Hemisphere
Southern
Best seen
Autumn (N. evening sky)
RA / Dec
0.4279h / -77.2542°

Knowledge connections

  • In constellationHydrus

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.