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AsteriaStar
Red giant · Triangulum Australe

Epsilon Trianguli Australis

Knowledge graphEpsilon TrAHR 5771HD 138538HIP 76440

Scientific overview

Epsilon Trianguli Australis is a red giant in the constellation Triangulum Australe (Trianguli Australis), lying about 201.7 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 typeK0III
Luminosity classIII
Apparent magnitude4.11
Absolute magnitude0.15
Luminosity (Sun = 1)75.579
Colour index (B−V)1.161
Distance201.7 ly (61.84 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 5823955832142075776 · elevated RUWE

Parallax15.1994 ± 0.1004 masSIMBAD · measured
Distance65.732 pcGaia · estimated
Proper motion (RA)24.318 mas/yrSIMBAD · measured
Proper motion (Dec)-55.216 mas/yrSIMBAD · measured
Radial velocity-14.07 ± 0.13 km/sSIMBAD · measured
Spectral typeK1/2IIISIMBAD · catalogued
Right ascension (ICRS)234.2 degSIMBAD · measured
Declination (ICRS)-66.317 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 5823955832142075776 · 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 · 2022yCat.1355....0G · direct catalogue measurement · retrieved 2026-07-11
  • Spectral type: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · sp_type · 1975MSS...C01....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
Triangulum Australe
Hemisphere
Southern
Best seen
Summer (N. evening sky)
RA / Dec
15.612h / -66.317°

Knowledge connections

  • In constellationTriangulum Australe

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.