transit photometry tagged posts

An artist’s conception of a view from within the Exocomet system KIC 3542116. Credit: Danielle Futselaar

Tails of comets seen streaking past a distant star. Scientists from MIT and other institutions, working closely with amateur astronomers, have spotted the dusty tails of 6 exocomets – comets outside our solar system – orbiting a faint star 800 light years from Earth. These cosmic balls of ice and dust, about the size of Halley’s Comet and traveled about 100,000 miles per hour before they ultimately vaporized, are some of the smallest objects yet found outside our own solar system.

The discovery marks the first time that an object as small as a comet has been detected using transit photometry, a technique by which astronomers observe a star’s light for telltale dips in intensity...

The most successful technique for finding planets beyond our solar system so far is transit photometry, which measures changes in a star’s brightness caused by a mini-eclipse. When a planet crosses in front of its star along our line of sight, it blocks some of the star’s light. If the dimming lasts for a set amount of time and occurs at regular intervals, it likely means an exoplanet is passing in front of, or transiting, the star once every orbital period.

NASA’s Kepler Space Telescope has used this technique to become the most successful planet-hunting spacecraft to date, with more than a thousand established discoveries and many more awaiting confirmation...