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Card 772 of 9992026-08-31 issue

Observed arrival · 2026-08-31

Sidereo, a pocket sky engine

sidereo.app Observed source
Editorial interest 84/100 Selection signal · not a rating of the site

An on-device astronomy companion that identifies stars, tracks planets, and lets you move through the night sky by gesture and time.

Landing page captured for the 2026-08-31 issue.

Field notes

The interface uses a movable aperture to identify objects inside the cursor while leaving the surrounding sky unlabelled. Scrolling advances the simulated clock rather than looping an animation, allowing a reader to inspect how the sky changes overnight. The page attributes its 9,096-star dataset to the Yale Bright Star Catalog and says planetary positions are calculated from Keplerian orbital elements. It also describes a native iPhone app using the same catalog file.

Observed signals

Read the marks

Editorial observations of this landing page, not a rating.

OpenPublic substance visible
PrettyNotable craft visible
ProPolished or operationally mature
NicheUnusually specific use

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Habitat Reduced to One Settee

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sidereo.app

Landing page observed 2026-08-31. The live site may have changed.