Ross 128
Scientific overview
Ross 128 is a red dwarf in the constellation Virgo (Virginis), lying about 10.94 light-years from Earth.
Class M. Cool red stars. The most common type in the galaxy, ranging from red dwarfs to red giants. Such stars have surface temperatures around 2,400–3,700 K and appear red to the eye.
Physical properties
| Spectral type | M4.5V |
| Luminosity class | V |
| Apparent magnitude | 11.12 |
| Absolute magnitude | 13.49 |
| Colour index (B−V) | 1.746 |
| Distance | 10.94 ly (3.36 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 3796072592206250624
| Parallax | 296.3 ± 0.0302 mas | SIMBAD · measured |
| Distance | 3.3742 pc | Gaia · estimated |
| Proper motion (RA) | 607.3 mas/yr | SIMBAD · measured |
| Proper motion (Dec) | -1223 mas/yr | SIMBAD · measured |
| Radial velocity | -30.66 ± 5.000e-4 km/s | SIMBAD · measured |
| Spectral type | dM4 | SIMBAD · catalogued |
| Effective temperature | 3093.4 K | Gaia · modeled |
| Radius | 0.2154 R_sun | Gaia · modeled |
| Surface gravity (log g) | 5.0554 log(cm/s^2) | Gaia · modeled |
| Metallicity [M/H] | -0.2009 dex | Gaia · modeled |
| Right ascension (ICRS) | 176.9 deg | SIMBAD · measured |
| Declination (ICRS) | 0.8046 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
- Distance: ESA Gaia astrometric survey · Gaia EDR3 · Bailer-Jones (2021) · external.gaiaedr3_distance · r_med_geo · row 3796072592206250624 · 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 · 2018MNRAS.475.1960F · direct catalogue measurement · retrieved 2026-07-11
- Spectral type: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · sp_type · 2019AJ....157...63K · catalogue identifier/value · retrieved 2026-07-11
- Effective temperature: ESA Gaia astrometric survey · Gaia DR3 · gaiadr3.astrophysical_parameters · teff_gspphot · row 3796072592206250624 · model output · retrieved 2026-07-11
- Radius: ESA Gaia astrometric survey · Gaia DR3 · gaiadr3.astrophysical_parameters · radius_gspphot · row 3796072592206250624 · model output · retrieved 2026-07-11
- Surface gravity (log g): ESA Gaia astrometric survey · Gaia DR3 · gaiadr3.astrophysical_parameters · logg_gspphot · row 3796072592206250624 · model output · retrieved 2026-07-11
- Metallicity [M/H]: ESA Gaia astrometric survey · Gaia DR3 · gaiadr3.astrophysical_parameters · mh_gspphot · row 3796072592206250624 · model output · 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 dwarf is a small, cool, low-mass main-sequence star. Red dwarfs burn their fuel so slowly that they can shine for tens of billions of years — far longer than the present age of the universe.
Location in the sky
Knowledge connections
- In constellationVirgo
- Orbited byRoss 128 b
Related stars in Virgo
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.