We’ve discovered thousands of planets beyond our solar system, but the vast majority of these have been observed indirectly by seeing how the planet affects the star around which it orbits. Recently, astronomers had the rare treat of observing an exoplanet directly — and it’s one of the youngest planets ever found.
Planet 2M0437b orbits far from its star, at around 100 times the distance between Earth and the sun, and is several times the mass of Jupiter. It formed a few million years ago, which is a blink of the eye in cosmic timescales, and it is so young that it is still hot from the energy released during its formation.
The planet was first spotted using the Subaru Telescope, located on Maunakea in Hawai’i, and was then further observed using the nearby W. M. Keck Observatory. Even with the help of the planet’s far distance from its star and its large size, it still took three years of observations to very the presence of the planet and to image it.
“This serendipitous discovery adds to an elite list of planets that we can directly observe with our telescopes,” said lead author Eric Gaidos, a professor at the University of Hawaiʻi at Mānoa, in a statement. “By analyzing the light from this planet we can say something about its composition, and perhaps where and how it formed in a long-vanished disk of gas and dust around its host star.”
In the future, the researchers want to see if they can measure the planet’s orbital motion around its star, and future telescopes like the upcoming James Webb Space Telescope could even be used to see the gases in its atmosphere or detect a moon-forming disk of matter around it.
“Two of the world’s largest telescopes, adaptive optics technology, and Maunakea’s clear skies were all needed to make this discovery,” said co-author Michael Liu, an astronomer at the Institute for Astronomy. “We are all looking forward to more such discoveries, and more detailed studies of such planets with the technologies and telescopes of the future.”