One star, three measured problems.

Sirius is the best-documented star system in the sky: 5,000 years of calendars, 160 years of astrometry, one white dwarf. The network runs three job families against that record — the orbit, the interior, the calendar. Each job takes public catalog values, runs them through the equations on this page, and returns a receipt anyone can replay. The token settles jobs on Robinhood Chain; the compute layer is, for now, this page — no production node network is running.

It started as a wobble in the ledger.

For five thousand years Sirius has been the calibration star of human time — the flood clock of Egypt, the dog days of Greece, the Celestial Wolf of China. Then in 1844 a Prussian mathematician noticed the star was not walking straight. The most famous unbuilt prediction in astronomy sat there for eighteen years. Here is the whole thread.

c. 2900 BC · Egypt

“Sothis rises, and the river follows.”

The heliacal rising of Sopdet — Sirius — announced the Nile flood. The 365-day civil calendar drifted a day every four years; the star's return to the same calendar date took 1,461 Egyptian civil years — the Sothic cycle, equal to 1,460 Julian years. Paraphrased

c. 700 BC · Greece

“When Sirius parches head and knees, the season of weariness is on men.”

Hesiod, Works and Days — the dog days of summer, named for the star: 3 July to 11 August on the Roman calendar. Paraphrased

1075 AD · Song China

“I would draw the bow like the full moon, and facing northwest, shoot the Celestial Wolf.”

Su Shi, Riverside City · Hunting at Mizhou (1075) — translated from the Chinese original. The Celestial Wolf of Chinese astronomy is Sirius.

Jan 1844 · Königsberg, Prussia

“The irregular motion of Sirius points to an unseen companion — a dark body gravitationally bound to the star.”

Friedrich Bessel, from wobbles in Sirius's proper motion (Astronomische Nachrichten, 1844). He published the prediction. He never saw it. Paraphrased

Jan 31, 1862 · Dearborn, USA

“The companion was seen — a tenth-magnitude point lost in the glare.”

Alvan Graham Clark, testing the 18.5-inch Dearborn refractor, split the Pup — the first white dwarf ever found, “only feebly self-luminous,” wrote Bond. Paraphrased

1925 · Mount Wilson, USA

“The redshift was measured — light climbing out of a star, weighed.”

Walter Adams confirmed the gravitational redshift of Sirius B: general relativity verified in starlight, and the white dwarf's density finally believed. Paraphrased

2005 · HST, low Earth orbit

“The Pup weighed at last: 1.018 ± 0.011 M☉ — a carbon-oxygen core inside an Earth-sized body.”

Bond, Barstow et al., HST astrometry and STIS spectroscopy (Bond et al. 2017). The 161-year audit closed: Bessel's dark star exists, and it is heavier than the Sun. Paraphrased

Sirius cannot share our clock.

The calendar argument is five thousand years old. The ledger argument is one number: 8.6. Light takes 8.6 years to cross the gap, so nothing that stays in step with Earth can settle a colony there — not a clock, not a calendar, not a ledger.

Cross-check: Bond et al. 2017 adopt a weighted parallax of 378.9 ± 1.4 mas → 8.61 ly. Both catalogs agree to 1%.

The two-ledger design is a design metaphor built on a real constraint — 8.6 years of one-way light time. It is not a deployed cross-star protocol, and nothing on this page claims it is.

And the money itself becomes mass and energy.

At Sirius the natural reserve is degenerate matter — Sirius B packs a solar mass into a body the size of Earth. A teaspoon of Sirius B's matter weighs about ten tonnes. Reserves are measured in mass and energy, computed rather than declared: every gram and every watt comes from a verified job on published data.

1.018 ± 0.011 M☉

Degenerate reserve · Sirius B · from mass-radius jobs

25.4 / 0.0245 L☉

Energy · luminosity · Sirius A ≈ 25.4 L☉ · Sirius B ≈ 0.0245 L☉

2 / 2

Audited settlements · Bessel 1844 predicted · HST 2005 weighed

Snapshot of — · nothing convertible, no exchange rate offered.

Explore the real sky.

Click anywhere on the chart. Every readout is computed on the spot — the star's altitude and azimuth right now, when it rises and sets today, and the dawn it first clears the Sun where you are. The dashed guide shows Orion's belt pointing at the Dog Star, the way it has for every winter in human history.

Workloads that resolve a star.

Three job families, each one a measurement rather than a rendering. A job takes published data, runs the equations locally, and returns a receipt anyone can replay. Click a card to watch the computation run again.

A preview, not a mainnet.

Two catalog instruments keep the Dog Star honest, and below them a preview ledger shows what receipts will look like. The catalog numbers are published values you can re-verify; the ledger entries are demo rows — no production network records them.

Gaia cannot measure Sirius — at −1.5 mag it saturates the detector (Bond et al. 2017). Teff = 25,369 ± 46 K from Barstow et al. 2017 STIS spectroscopy; masses and B's radius from Bond et al. 2017; Sirius A's radius from Davis et al. 2011 interferometry.

From cycles to discovery.

Public catalogs in → three job families → a replayable receipt → L2 settlement. $SIRIUS buys compute cycles — not dividends, not equity, not ownership of Sirius.

$SIRIUS settles on Robinhood Chain.

The two-ledger argument needs somewhere for the Earth book to live, and it has to be somewhere cheap enough to pay for a compute job and final enough that the receipt still means something years later. Robinhood Chain is an Arbitrum Orbit layer 2 that has been open and permissionless since July 1, 2026. Jobs clear on the L2 in the time it takes to read this sentence, and the batches settle down to Ethereum. Gas is paid in ETH, not in $SIRIUS, so dispatching work never competes with securing the chain.