GW170817 remnant
NO ACCRETION · SCHWARZSCHILD FROM 2.7 M☉ · ACCRETION NONE
OVERVIEW
] BLACK HOLEGW170817 remnant is a stellar-mass black hole in the constellation Hydra, 130.0 from Earth. Its mass is 2.70 . It was discovered in 2017.
Probably the lightest black hole known, and the only one whose birth was both heard and seen: two neutron stars merged, gravitational waves arrived first, and telescopes caught the afterglow that forged heavy elements.
- WHAT IT IS
- Stellar-mass black hole
- HOW FAR
- 130.0
The light arriving now left it that long ago.
THE MODEL
] SHADOW ONLYCALCULATED · NOT AN OBSERVATION · SCHWARZSCHILD RADIUS FROM THE MASS · 2.7 M☉ · ACCRETION NONE
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 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.
OBSERVING
] FROM WHERE YOU AREWhat it takes to see GW170817 remnant 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 GW170817 remnant 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
- 21.7
- PROPER MOTION SINCE
- none published
Computed for 2026-08-27 00:00 UT. No proper motion is published for GW170817 remnant, 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 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.
- Accretion state
- none — a merger remnant, with nothing left to accrete
- Mass
- 2.7
ALSO KNOWN AS
] 1 DESIGNATIONS- Gravitational wave event GW170817
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.
- SIMBADGW170817
Cross-identifications, measured values and the reference behind each of them.
- ADSobject:"GW170817"
Papers indexed against this object rather than against the string, newest first.
- VizieR5″ around 197.4487 -23.3840
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. GW170817 remnant [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/gw170817-remnant
@misc{spacecatalog_gw170817-remnant,
author = {{SpaceCatalog}},
title = {{GW170817 remnant}},
howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},
year = {2026},
url = {https://spacecatalog.org/object/gw170817-remnant},
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
] 2 ITEMS- The long-term evolution of the GW170817 remnant2024-03-13 · arXiv · PAPER · Menquan Liu, Jie Zhang, Cong Wang
- Piecewise frequency model for searches for long-transient gravitational waves from young neutron stars2023-10-19 · arXiv · PAPER · Benjamin Grace, Karl Wette, Susan M. Scott, Ling Sun
arXiv · UPDATED DAILY