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GW190421_213856 | Gravitational-wave mergers | Apex Andromeda | Apex Andromeda

Black Holes/Gravitational-wave mergers/GW190421_213856

ConfirmedBinary Black Hole

GWOSC compact-binary event

GW190421_213856

Both component-mass lower bounds exceed 3 solar masses

Primary mass42 M☉

Secondary mass32 M☉

ObservedApr 21, 2019

Event identity

Classification and release

ID: gwtc:GW190421_213856
Event name: GW190421_213856
Classification: Binary Black Hole
Composition status: Confirmed
Confidence boundary: Both component-mass lower bounds exceed 3 solar masses
Catalog: GWTC-2.1-confident
Preferred event version: v2
Observed at: Sunday, April 21, 2019 at 9:38:56 PM UTC UTC
GPS time: 1,239,917,954.2

Source-frame posterior

Component and remnant masses

Primary mass: 42 (-7.4, +10.1) M☉
Secondary mass: 32 (-9.8, +8.3) M☉
Remnant mass: 70.5 (-9, +12.4) M☉
Effective spin: -0.1
Network SNR: 10.7

Propagation

Distance and statistical context

Luminosity distance: 2,590 (-1,240, +1,490) Mpc
Redshift: 0.45
Astrophysical probability: 0.9979
False-alarm rate: 0.0028

Provenance

Official source record

GWOSC · GWTC-2.1-confident

GW190421_213856

Last synchronized 9/12/2026, 3:20:17 AM UTC.

JSON record GWOSC event page