Stellar
87. flare hits HD 189733b
(artist’s impression)
This artist’s impression shows exoplanet HD 189733b, as it passes in front of its parent star, called HD 189733A. Hubble’s
instruments observed the system in 2010, and in 2011 following a large flare from the star (depicted in the image).
Following the flare, Hubble observed the planet’s atmosphere evaporating at a rate of over 1000 tonnes per second.
In this picture, the surface of the star, which is around 80% the mass of the Sun, is based on observations of the Sun from
the Solar Dynamics Observatory.
Credit: NASA, ESA, L. Calçada
“I study the atmospheres of planets orbiting nearby stars (also known as
exoplanets), and it’s safe to say that this field is completely dominated by space
telescopes, including both Hubble and Spitzer.
“Thirteen years ago Hubble was the first telescope to detect the atmosphere of
an extrasolar planet, and today we are using the same techniques to study the
atmospheres of an entirely new class of planets known as ‘super-Earths.’ These
worlds have masses between 1-10 times that of the Earth and compositions
ranging from dense rock to puffy, hydrogen- or water-rich ‘mini-Neptunes’. They
are the most common kind of extrasolar planet found in our surveys of
nearby stars, yet we don’t have one in our own solar system. By studying the
atmospheres of these planets we can gain important clues that will help us to
understand their mysterious origins.”
— Dr. Heather Knutson
Assistant Professor of Planetary Science
California Institute of Technology