Are these real detections?

They're real published candidates — the automated alerts LIGO, Virgo and KAGRA release within minutes of a trigger. Many are later reclassified as noise or retracted, which is why the terrestrial probability is shown alongside the astrophysical ones.

Does it need an API key?

No. GraceDB's public superevent feed is key-less; a small background script fetches it and saves a snapshot the saver reads.

Does it work offline?

The last snapshot the pipeline saved will still draw, but new alerts need an internet connection to arrive.

What does the false-alarm rate mean?

It's how often detector noise alone would be expected to fake an event that loud — one per five million years means a very confident detection, one per few months means treat it as noise.

Yes — free, no download, in your browser.

Gravitational Wave Alerts Screensaver

The Gravitational Wave Alerts screensaver shows real public candidate alerts from GraceDB, the alert database the LIGO, Virgo and KAGRA gravitational-wave detectors publish to, with each event's real classification probabilities and false-alarm rate. It's free, needs an internet connection, and ESC exits.

How the Gravitational Wave Alerts screensaver works

A background pipeline reads GraceDB's public superevent list — the same key-less feed astronomers watch for follow-up targets.

Each card carries a real event id like S251118cm, how long ago the candidate was recorded, and its alert type.

The stacked bar splits the detection's own probabilities between a black-hole merger (BBH), a neutron-star merger (BNS), a mixed neutron-star/black-hole merger (NSBH) and terrestrial noise.

Distance appears in megaparsecs with a billion-light-year conversion when GraceDB has published it, and the false-alarm rate reads as one false alarm per so many years.

A worked example

A card reading S251118cm · 99% Terrestrial tells you the pipeline thinks that candidate was almost certainly detector noise, not a merger — while an event dominated by a purple BBH segment with a false alarm rate of one per five million years is the kind that sends telescopes hunting. Drop it into Multi-view next to a sky map for an observatory wall.

Settings & tips

Seconds per page sets how long each screenful of alerts holds before the list cycles to the next.
Alerts are listed most recent first; on a small Multi-view cell fewer cards fit, so the cycling does more work.
Run automation/run.py gwalerts on your pipeline machine to refresh the alert list.

Frequently asked questions

Are these real detections?: They're real published candidates — the automated alerts LIGO, Virgo and KAGRA release within minutes of a trigger. Many are later reclassified as noise or retracted, which is why the terrestrial probability is shown alongside the astrophysical ones.
Does it need an API key?: No. GraceDB's public superevent feed is key-less; a small background script fetches it and saves a snapshot the saver reads.
Does it work offline?: The last snapshot the pipeline saved will still draw, but new alerts need an internet connection to arrive.
What does the false-alarm rate mean?: It's how often detector noise alone would be expected to fake an event that loud — one per five million years means a very confident detection, one per few months means treat it as noise.
Is it free?: Yes — free, no download, in your browser.

← All Space & Astronomy screensavers