Mondo Knows Facts
A planet crossing its star dims the light
The size of the dip gives the planet's radius compared with its star's When a planet passes in front of its star, the star fades by the ratio of their cross sections. A Jupiter-sized world crossing a Sun-like star dims it by about one percent. The alignment has to be close to edge-on, so only a small fraction of systems show transits, which is why surveys watch so many stars at once. It sits in Mondo's space collection, one of 200 facts that each trace back to the reference below.
Where this comes from
Facts that can change over time are reviewed and updated. If something here looks wrong, Mondo would rather know than be confidently incorrect.
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Tags: exoplanets, transits, photometry
A planet crossing its star dims the light: the short answers
- Where does this come from, and can I check it?
- The size of the dip gives the planet's radius compared with its star's. The figure is taken from NASA Science, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.
- Is this really a space fact?
- Yes. It sits on the Space shelf, one of 2,600 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.
- What else can I read about it?
- The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.