An international team of astronomers says they have managed to take the first visible light spectrum from an exoplanet, giving them yet another new tool to probe the nature of the exoplanet known as 51 Pegasi b, otherwise known as "hot Jupiter."
These new findings, published in the journal Astronomy & Astrophysics, offer a promising way forward to study exoplanets that doesn't rely on waiting for a distant planet to pass in front of its host star.
"This result is encouraging and constitutes a very valuable proof of concept," the study authors wrote. "Our method can be used to recover an exoplanet's spectroscopic reflected signature from among the stellar noise, despite the extremely low planet-to-star flux ratio."
The planet 51 Pegasi b was the first confirmed discovery of a planet around a sun like star. The planet, whose star sits about 50 light years away in the constellation Pegasus, was found in 1995 and is seen as a "hot Jupiter" - a planet that is the same size class as Jupiter but that orbits extremely close to their home stars.
Since its discovery, more than 1,900 exoplanets have been found but little is known about any of these distant worlds. Much of what we do know has been learned the planets as it transits across the surface of its star, blocking a little bit of starlight in the process.
"The search for exoplanets has been following two different, but complementary, paths: the detection of exoplanets with increasingly lower masses, and the characterization of these exoplanets and their atmospheres," the study authors wrote.
The fact that scientists were able to pick out this weak signal using the HARPS tells them that the much stronger instruments that will be coming out soon will be able to pick up light coming from even more exoplanets, the authors wrote. Two of the instruments that researchers are looking forward to are the ESPRESSO instrument at the Very Large Telescope as well as the ESO's European Extremely Large Telescope.
"These encouraging results clearly show a bright future for this type of studies when next-generation instruments (e.g., ESPRESSO at the VLT) and telescopes (e.g., ESO's E-ELT) become available to the community," they wrote. "The sheer increase in precision and collecting power will allow for the detection of reflected light from smaller planets, planets on orbits with longer periods, or an increase in detail for larger planets like 51 Peg b."
