Arkab Posterior
Scientific overview
Arkab Posterior is a star in the constellation Sagittarius (Sagittarii), lying about 134.17 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 type | F2III |
| Luminosity class | III |
| Apparent magnitude | 4.27 |
| Absolute magnitude | 1.2 |
| Luminosity (Sun = 1) | 28.867 |
| Colour index (B−V) | 0.35 |
| Distance | 134.17 ly (41.14 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 6664407333374099968 · elevated RUWE
| Parallax | 23.3612 ± 0.2744 mas | SIMBAD · measured |
| Distance | 42.6385 pc | Gaia · estimated |
| Proper motion (RA) | 93.218 mas/yr | SIMBAD · measured |
| Proper motion (Dec) | -53.775 mas/yr | SIMBAD · measured |
| Radial velocity | 11.5 ± 1 km/s | SIMBAD · measured |
| Spectral type | F2/3V | SIMBAD · catalogued |
| Right ascension (ICRS) | 290.8 deg | SIMBAD · measured |
| Declination (ICRS) | -44.7998 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 6664407333374099968 · 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 · 2018yCat.1345....0G · direct catalogue measurement · retrieved 2026-07-11
- Spectral type: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · sp_type · 1978MSS...C02....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.
Location in the sky
Knowledge connections
- In constellationSagittarius
Related stars in Sagittarius
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.