Photograph of TON 618, a supermassive black hole in Canes Venatici.
[

OVERVIEW

] BLACK HOLE

TON 618 is a supermassive black hole in the constellation Canes Venatici, 10.80 from Earth. Its mass is 6.6×10¹⁰ . It was discovered in 1957.

One of the most massive black holes known — sixty-six billion Suns. It powers a hyperluminous quasar whose light left it when the universe was less than a third of its current age.

WHAT IT IS
Supermassive black hole
HOW FAR
10.80

The light arriving now left it that long ago.

WHERE TO LOOK
Canes Venatici

The patch of sky it sits in, as seen from Earth.

[

THE MODEL

] LENSED
OUTSIDE THE SURVEYED VOLUME · DRAG TO ORBIT

CALCULATED · NOT AN OBSERVATION · SCHWARZSCHILD RADIUS FROM THE MASS · 6.6×10¹⁰ M☉ · ACCRETION QUASAR · INCLINATION NOT MEASURED · DISC PEAK 22 400 K

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. The disc starts at the innermost stable circular orbit and its colour is a temperature computed from this object's own mass; one turn of its inner edge really takes 3×10⁷ seconds. 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 what is in the frame is that whole neighbourhood seen from outside it, piled into a knot around the Sun. The rest of the sky from here is not something this catalogue knows.

[

IMAGES

] 1 FRAMES
  • Sloan Digital Sky Survey, Apache Point Observatory, Astrophysical Research Consortium
    CC BY 4.0
[

OBSERVING

] FROM WHERE YOU ARE

What it takes to see TON 618 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.

TONIGHT

Say where you are, and this line says when TON 618 is worth going out for.

[

APPARENT PLACE

] EQUINOX J2026.7

Where 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
19.3
PROPER MOTION SINCE
none published

Computed for 2026-08-27 00:00 UT. No proper motion is published for TON 618, 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

] 2 FIELDS

The 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.

Accretion state
quasar — a thin disc near its Eddington limit
Mass
6.6×10¹⁰
[

ALSO KNOWN AS

] 1 DESIGNATIONS
  • Common name TON 618
[

LOOK IT UP ELSEWHERE

] 3 SERVICES

Each 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.

[

CITE THIS PAGE

] DR1

This 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.

PLAIN TEXT
SpaceCatalog. TON 618 [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/ton-618
BIBTEX
@misc{spacecatalog_ton-618,
  author       = {{SpaceCatalog}},
  title        = {{TON 618}},
  howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},
  year         = {2026},
  url          = {https://spacecatalog.org/object/ton-618},
  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.

[

RELATED OBJECTS

] 8 LINKED