Each field explained

Status
Preliminary

An automatic alert sent within minutes of the signal. Later analysis can change these numbers, confirm the event with a GW name, or withdraw it.

Significance
Low significance

Low significance: shared openly, but below the bar for a significant alert. Many of these are noise.

What it was
  • Noise in the detectors91.1%
  • Two black holes8.9%
  • A neutron star and a black hole< 0.1%
  • Two neutron stars< 0.1%

How likely each kind of source is, from the latest public alert. The numbers come from how the signal looked, not from a person's judgement.

Distance
About 12 billion light-years (3,700 ± 1,200 megaparsecs)

Estimated from how loud the signal was: a quieter wave came from further away. The spread is large in a first alert, and it shrinks as the analysis is refined.

False alarm rate
About once every 18 hours

How often noise alone would make a signal at least this strong. The rarer, the more likely it is real.

Detectors
LIGO Hanford and LIGO Livingston

The observatories that saw the signal. More detectors means a better position on the sky.

When

When the signal reached Earth, in UTC.

Latest alert
Preliminary

Each alert replaces the numbers of the one before it.