Tabby’s star, otherwise known as the most mysterious star in the galaxy, is dipping drastically in brightness, giving astronomers an opportunity to figure out what has been causing this star’s weird behavior.
Ever since the Kepler space telescope captured a series of random-seeming dips from a certain mysterious star, astronomers and the public alike have been baffled by its behavior. Then, following the end of the main Kepler mission, the star went quiet.
Now, at long last, the star has begun a steep decline in brightness — it’s already 2% dimmer after a single night of observation — and telescopes all over the world are at the ready. For the first time, astronomers are catching Tabby’s star in the act, and that means the mystery of what causes the star to dip and dim in brightness may soon be solved.
What We Already Know About Tabby’s Star
What is now famously known as Tabby’s Star is a normal-looking F-class star in the field of the Kepler space telescope. Kepler’s mission was to monitor more than 150,000 stars, watching for the minute dips in brightness that would signal an exoplanet moving across the face of its parent star from Earth’s perspective. But in Tabby’s Star, Kepler — and the watchful eyes of citizen scientists involved in the Planet Hunters project — found something completely different.
Tabby’s Star was observed to dim 10 times, sometimes by 1% (typical of a giant exoplanet transit) and sometimes by 10% to 20% (not at all typical of exoplanet transits, or anything else for that matter), each dimming lasting days to weeks at a time. The dips were irregular both in terms of how long they were and when they occurred.