HR 4171
Scientific overview
HR 4171 is a star in the constellation Hydra (Hydrae), lying about 210.56 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 type | G8III |
| Luminosity class | III |
| Apparent magnitude | 4.91 |
| Absolute magnitude | 0.86 |
| Luminosity (Sun = 1) | 39.446 |
| Colour index (B−V) | 0.922 |
| Distance | 210.56 ly (64.56 pc) |
Values are real catalogue data; fields without a reliable value are omitted, never estimated.
Precision measurements
Astrometry and astrophysics from SIMBAD
| Parallax | 12.4255 ± 0.228 mas | SIMBAD · measured |
| Proper motion (RA) | -95.499 mas/yr | SIMBAD · measured |
| Proper motion (Dec) | 25.027 mas/yr | SIMBAD · measured |
| Radial velocity | 16.58 ± 0.67 km/s | SIMBAD · measured |
| Spectral type | G8IIIb | SIMBAD · catalogued |
| Right ascension (ICRS) | 159.6 deg | SIMBAD · measured |
| Declination (ICRS) | -16.8766 deg | SIMBAD · 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 · 2008AJ....135..209M · direct catalogue measurement · retrieved 2026-07-11
- Spectral type: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · sp_type · 1989ApJS...71..245K · 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.
Location in the sky
Knowledge connections
- In constellationHydra
Related stars in Hydra
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.