OVERVIEW
] BLACK HOLEA0620-00 is a stellar-mass black hole in the constellation Monoceros, 3300 from Earth. Its mass is 6.60 . It was discovered in 1975.
The nearest known black hole for almost fifty years, until Gaia's dormant finds displaced it — quietly orbiting with a small orange star that loops around it every 7.75 .
- WHAT IT IS
- Stellar-mass black hole
- HOW FAR
- 3300
The light arriving now left it that long ago.
THE MODEL
] SHADOW ONLYCALCULATED · NOT AN OBSERVATION · SCHWARZSCHILD RADIUS FROM THE MASS · 6.6 M☉ · ACCRETION QUIESCENT · SKY BENT AROUND THE HOLE
The black disc is the shadow, 2.6 times wider than the horizon that casts it, and every ray in the frame is a null geodesic of the Schwarzschild metric. Nothing is falling in, so there is nothing else to see. 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, drawn from where the camera actually is — but every one of them is within 170 parsecs of the Sun and this object is much further out, so from here that whole neighbourhood is a knot in one direction and the rest of the sky is empty. The view you land on looks the other way; turn back towards the Sun and the stars come with it. What the readout says is which of the two the frame is pointed at. The emptiness is not a missing backdrop — it is the edge of what this catalogue has measured. And they are not where they are. Light that passes a black hole is bent towards it, so every star behind this one is seen further from it than it stands: the ones almost directly behind swing out into a ring and brighten as they go, the sky immediately around the shadow is emptied to fill that ring, and part of the ring is light from stars behind you, carried round the far side. Turn the view and watch a star climb out of the middle rather than cross it. Each one is still a measured parallax — moved along the path the metric gives its light, and nothing else.
IMAGES
] 1 FRAMES- Sloan Digital Sky Survey
CC BY 4.0
OBSERVING
] FROM WHERE YOU AREWhat it takes to see A0620-00 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 A0620-00 is worth going out for.
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
- 20.6
- PROPER MOTION SINCE
- none published
Computed for 2026-09-11 00:00 UT. No proper motion is published for A0620-00, so nothing here moves the object; what separates this from the catalogued position above is the coordinate grid turning 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
] 3 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 KIND OF THING IT IS
What the object is in itself, rather than how it happens to look from here.
- Accretion state
- quiescent — between outbursts
- Mass
- 6.6
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.
- Accretion plane inclination
- 51
ALSO KNOWN AS
] 1 DESIGNATIONS- Common name A0620-00
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.
- SIMBADV616 Mon
Cross-identifications, measured values and the reference behind each of them.
- ADSobject:"V616 Mon"
Papers indexed against this object rather than against the string, newest first.
- VizieR5″ around 95.6856 -0.3456
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. A0620-00 [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/a0620-00
@misc{spacecatalog_a0620-00,
author = {{SpaceCatalog}},
title = {{A0620-00}},
howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},
year = {2026},
url = {https://spacecatalog.org/object/a0620-00},
note = {Catalogue entry, data release DR1 (2026-08-21). Values from SpaceCatalog curated data.}
}The values above were taken from SpaceCatalog curated data — CC-BY-4.0. Citing this page does not replace citing that catalogue.
RECENT ACTIVITY
] 3 ITEMS- Superorbital variability in the quiescent black hole X-ray transient A0620-002026-07-17 · arXiv · PAPER · Enzo A. Saavedra, Roi Alonso, Teo Muñoz-Darias, Jorge Casares, Manuel A. P. Torres, Montserrat Armas Padilla
- Low-mass X-ray binaries as a probe of Kerr-MOG black hole spacetime2026-06-23 · arXiv · PAPER · Bakhodirkhon Saidov, Bakhtiyor Narzilloev, Ibrar Hussain, Bobomurat Ahmedov
- Low-mass X-ray binaries as a probe of Kerr-MOG black hole spacetime2026-06-23 · arXiv · PAPER · Bakhodirkhon Saidov, Bakhtiyor Narzilloev, Ibrar Hussain, Bobomurat Ahmedov
arXiv · UPDATED DAILY