Astronomy

Reconstructing an unseen asteroid

Watch a star disappear behind an asteroid. Change the observing track and combine multiple chords to infer the object's size and shape.

By Mykhailo Makarov

Actual application image

The model and its limits

An elliptical opaque silhouette and a uniform partially opaque ring, occulting a point star. Finite stellar size, diffraction and limb topography are omitted. Station chords share the object's projection plane.

Equations used in the module

Equations
chord = 2a√(1−y²/b²); duration = chord/v; transmitted flux = 1−opacity.

Related experiments

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Astronomy

Reading the light of two stars

Tilt a binary orbit until eclipses appear. Unequal eclipse depths reveal different surface brightnesses; their widths constrain stellar radii.

Astronomy

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Balance an outward stellar wind against an incoming interstellar flow. Change density or speed and watch the stand-off distance respond.

Astronomy

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