OVERVIEW
] STARRigil Kentaurus is a G2V yellow main-sequence star in the constellation Centaurus, 4.321 from Earth, shining at apparent magnitude −0.01 (). It is catalogued as α¹ Cen, Gl 559A and HD 128620, among 6 designations in total. It has been known since antiquity.
The closest star system to the Sun, and a Sun-like star in its own right. What looks like one point of light is three: two solar-type stars orbiting each other, with Proxima Centauri circling far outside.
- WHAT IT IS
- Yellow main-sequence star
- HOW FAR
- 4.321
- HOW BRIGHT (V)
The light arriving now left it that long ago.
Bright enough for the naked eye, under a sky dark enough.
THE MODEL
] RADIUS FROM THE LUMINOSITY AND THE TEMPERATURECALCULATED · NOT AN OBSERVATION · RADIUS FROM THE LUMINOSITY AND THE TEMPERATURE · SPECTRAL TYPE G2V · 5780 K · 1.54 L☉ · VARIABLE, MAG -0.09–0.11
Drawn from the radius from the luminosity and the temperature and from the same properties the picture at the top of this page uses, at the distance a flight to it would stop. Drag it, or use the arrow keys, to look from another direction. The stars behind are the 498,631 this catalogue holds real distances for, at their real positions and drawn from where the camera actually is — so the constellations are wrong, and that is the point. This is the sky from there, not the sky from here.
IMAGES
] 1 FRAMES- Digitized Sky Survey 2
CC BY 4.0
OBSERVING
] FROM WHERE YOU AREWhat it takes to see Rigil Kentaurus for yourself. Everything in this part of the page is worked out for a real horizon, a real night and the equipment you say you have.
Say where you are, and this line says when Rigil Kentaurus is worth going out for.
THROUGH AN EYEPIECE
] 150 MM TELESCOPE · 25 MM EYEPIECEBright enough to pick out with your eyes alone, and from a lit street as well as a dark one. It will be a point of light in anything: a star is far enough away that no aperture on Earth gives it a width, and all the equipment changes is how easily you find it.
- 48×
- 1.08
- 1.25
- 13.0
- APPARENT MAGNITUDE ()
- −0.01 · within reach
APPARENT PLACE
] EQUINOX J2026.7Where a telescope has to be pointed today, which is not quite where the catalogue records the object: the coordinate grid itself has turned since the year 2000 the catalogue is referred to.
- RIGHT ASCENSION
- DECLINATION
- GRID TURNED SINCE
- 16.5
- PROPER MOTION SINCE
- 1.6
Computed for 2026-08-27 00:00 UT. Two things separate it from the catalogued position above: Rigil Kentaurus has moved under its own proper motion, and the coordinate grid has turned under it — about fifty arcseconds a year of precession since 2000, and the small nodding of the Earth’s axis on top of that. Aberration and refraction are not included, and neither is parallax; each is under an arcminute, which is also about as well as the catalogued position is known. The same figure for any date.
CATALOG DATA
] 9 FIELDSThe raw catalogue values, as the source published them, with the error bars where one was published — sorted by what each set of figures is about rather than by the order they happened to be stored in.
WHAT IT IS MADE OF
What the object is in itself, rather than how it happens to look from here.
- Spectral type
- Luminosity
- 1.54312
HOW BRIGHT IT IS
What the light adds up to, measured through one filter at a time. A magnitude is a brightness on a backwards scale — the smaller the number, the brighter the object.
- Colour index (B−V)
- Variable magnitude, brightest
- Variable magnitude, faintest
WHERE IT IS AND HOW IT MOVES
Position, motion across the sky and the size it covers on it. These are measurements of the object as seen from here, so every one of them depends on where here is.
- Proper motion (RA)
- −3678.19
- Proper motion (Dec)
- 481.84
- Radial velocity
- −26.2
WHERE THESE FIGURES CAME FROM
Which catalogue, paper or model each of the fields above was read from, where the source named one.
- Spectral type from
- SIMBAD (2006A&A...460..695T, quality C)
ALSO KNOWN AS
] 6 DESIGNATIONS- Bayer/Flamsteed α¹ Cen
- Common name Rigil Kentaurus
- Gliese Gl 559A
- HD HD 128620
- HIP HIP 71683
- HR HR 5459
LOOK IT UP ELSEWHERE
] 3 SERVICESEach link carries the identifier printed beside it. Nothing on this page is a measurement of our own, so a number that disagrees with one of these is worth reporting — and a service that has never catalogued this object under this name will say so plainly.
- SIMBADHR 5459
Cross-identifications, measured values and the reference behind each of them.
- ADSobject:"HR 5459"
Papers indexed against this object rather than against the string, newest first.
- VizieR5″ around 219.9115 -60.8340
Every published table with a row at this position, searched by coordinates rather than by name.
CITE THIS PAGE
] DR1This page is live and its numbers move when an upstream refreshes, so the citation names the release the rows belong to rather than the day you read them. The release itself is frozen, republished as a bundle, and is what a data-availability statement should point at.
SpaceCatalog. Rigil Kentaurus [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/rigil-kentaurus
@misc{spacecatalog_rigil-kentaurus,
author = {{SpaceCatalog}},
title = {{Rigil Kentaurus}},
howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},
year = {2026},
url = {https://spacecatalog.org/object/rigil-kentaurus},
note = {Catalogue entry, data release DR1 (2026-08-21). Values from HYG Database v4.1.}
}The values above were taken from HYG Database v4.1 — CC-BY-SA-4.0. Citing this page does not replace citing that catalogue, and its licence is share-alike: the terms reach whatever you build from these rows.