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Subgiant · Leo

Iota Leonis

Knowledge graphIota Leo78 LeoHR 4399HD 99028

Scientific overview

Iota Leonis is a subgiant in the constellation Leo (Leonis), lying about 77.21 light-years from Earth.

Class F. Yellow-white stars, somewhat hotter and more massive than the Sun. Such stars have surface temperatures around 6,000–7,500 K and appear yellow-white to the eye.

Physical properties

Spectral typeF2IV SB
Luminosity classIV
Apparent magnitude4
Absolute magnitude2.13
Luminosity (Sun = 1)12.257
Colour index (B−V)0.423
Distance77.21 ly (23.67 pc)

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

Precision measurements

Astrometry and astrophysics from SIMBAD

Parallax42.3548 ± 0.3984 masSIMBAD · measured
Proper motion (RA)149.4 mas/yrSIMBAD · measured
Proper motion (Dec)-80.702 mas/yrSIMBAD · measured
Radial velocity-25.4 ± 0.3 km/sSIMBAD · measured
Spectral typeF1IVSIMBAD · catalogued
Right ascension (ICRS)171 degSIMBAD · measured
Declination (ICRS)10.5295 degSIMBAD · measured
Full field-level provenance
  • Parallax: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · plx_value · 2018yCat.1345....0G · direct catalogue measurement · retrieved 2026-07-11
  • Proper motion (RA): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · pmra · 2018yCat.1345....0G · direct catalogue measurement · retrieved 2026-07-11
  • Proper motion (Dec): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · pmdec · 2018yCat.1345....0G · direct catalogue measurement · retrieved 2026-07-11
  • Radial velocity: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · rvz_radvel · 2023MNRAS.519.5472M · direct catalogue measurement · retrieved 2026-07-11
  • Spectral type: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · sp_type · 1976AJ.....81..245E · catalogue identifier/value · retrieved 2026-07-11
  • Right ascension (ICRS): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · ra · 2018yCat.1345....0G · direct catalogue measurement · retrieved 2026-07-11
  • Declination (ICRS): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · dec · 2018yCat.1345....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 subgiant has begun to evolve off the main sequence, brightening and expanding as core hydrogen fusion ends.

Location in the sky

Constellation
Leo
Hemisphere
Both (equatorial)
Best seen
Spring (N. evening sky)
RA / Dec
11.3987h / 10.5295°

Knowledge connections

  • In constellationLeo

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.