i What a cadence is
Each five-minute look at the star alternates with a look somewhere else. A signal from the star should follow the telescope: there in every ON, gone in every OFF.
seti-hunter · a public survey · Green Bank · 1.1–2.8 GHz
Listening to 1,133 stars for the signals nobody else looked for.
Every star Breakthrough Listen pointed the Green Bank Telescope at for its 2016–2019 survey, searched again for wide, curving, flickering and comb-shaped radio signals. Everything the search flags goes down the same five-rung ladder in public, and this page shows the reason each one was eliminated.
The expected answer is a limit, not a detection. A survivor becomes a request to look again, never a claim.
- stars searched
- —
- signals flagged
- —
- eliminated, with a reason
- —
- under private review
- —
…
01
Three ideas carry the page
How the telescope looks, what a real signal’s fingerprint is, and the ladder every flagged signal climbs down.
ii The three fingerprints
Bar height is signal strength in each of the six scans; the dashed line is the detection threshold. Only the first pattern survives rungs 1 and 2. Fingerprints here are drawn as a guide, not data.
iii The ladder, in order
- 1Present in any OFF scan
- 2Missing from any ON scan
- 3An instrument artifact: a coarse-channel spike or edge
- 4Inside a known human transmitter band
- 5Also seen around another star
- ✓Passes all five → private review
Every flagged signal goes down the same rungs, frozen before the run. The page records the first rung that eliminated it.
02
The Funnel
The whole survey in one picture. Every signal the detectors flag lands in exactly one row, so the rows add up to the top line. Click a rung to see what it eliminated.
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Bar length: share of all flagged signals (linear). “Pending final check” changes once a day, from the 00:00 UTC batch, so its jumps are a day’s worth of stars at once. A star’s eliminations are listed once nothing of it waits on rung 5, and every star’s once the run ends.
03
The sky we’re listening to
Every dot is a real star from the sample, at its real position; the glowing band is the Milky Way. Stars whose eliminations are published light up gold. Replay plays the original 2016–2019 observing in the order the telescope visited them.
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2016–2019
- L- and S-band
- L-band only
- S-band only
- eliminations published
Hammer–Aitoff projection, equatorial coordinates, right ascension increasing to the left. Hover or tap a star for its name.
04
The band we’re listening in
1.1 to 2.8 GHz. Amber bands are human transmitters, read from the frozen ladder that rung 4 uses. Hatched bands are receiver filters that record nothing; blue is nature’s quiet zone, the water hole. Pins are eliminated signals, coloured by the rung that eliminated them.
…swipe the band →
05
The Weird Wall
The real ON-scan waterfalls (time runs up, frequency runs across), sorted by how weird the detector thought they were, each stamped with its fate. The gold slot is kept for anything nothing could explain. Click any tile for its Ledger entry.
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Figures update once a day; numbers every ~15 minutes, so the Wall and the Ledger trail the Funnel by about a day. The Wall shows the weirdest signals that have cutouts; type a starThe Wall shows the weirdest few hundred; type a star’s full name to load its whole list.rsquo;s full name to load its whole list. A star’s list appears once nothing of it waits on rung 5, and every star’s once the run ends.
06
While the run is going
A heartbeat for the weeks the survey runs unattended on one machine at home: which star is streaming, which of its six scans is being read, and how far along the run is.
…
—of 1,133 stars
now reading
—
ONOFFONOFFONOFF
streamed
—
cadences scored
—
parked after 3 tries
—
incomplete, listed
—
download speed, recent cadences
Figures update daily; numbers every ~15 minutes. A parked cadence failed three times and is listed as not analysed, never silently skipped.
07
Where the claims stop
BOUNDARY
Covered
- Four committed shapes, each with an upper limit measured from planted signals in the real files: wide drifting carriers, fast and curving drifts, intermittent tones, and combs.
- An open-ended “weird anything” channel that goes down the same ladder, with no limit claimed for it.
- Drift rates from 0 to about ±95 Hz/s, the edge of the drift bank.
- L- and S-band (1.1–2.8 GHz) mid-resolution Green Bank files, about 2.86 kHz by 1.07 s, complete six-scan cadences only. Incomplete cadences are counted and listed, not scored.
Not searched
- Hz-narrow tones, beyond using them to calibrate. That is the ground of Price et al. 2020, Ma et al. 2023 and Painter et al. 2024.
- Millisecond pulses: one-second sampling can’t see them.
- Parkes data, C- and X-band, and any star outside Price 2020’s Green Bank tables.
An elimination is a reason, not a verdict on the star.
Four things this page will never show
- A signal waiting on rung 5. Only a count, changed once a day.
- A star’s list while any of its signals still waits on rung 5.
- The star, frequency or date of a signal under private review. Only the count, and the four-step tracker.
- Anything the run’s state file holds that isn’t on the published contract. The survey redacts it, and the site’s proxy redacts it again.