A new hope? Maybe?
The measurements made by ESPRESSO may have delivered something of an unexpected surprise. The planet may not be alone in it’s Goldilocks Zone. The astronomers found a second signal in data collected by the spectrograph, the source of which they have yet to identify. If the origin of the signal is an exoplanet, it could be a first for the detection of such bodies.
“If the signal was planetary in origin, this potential other planet accompanying Proxima b would have a mass less than one-third of the mass of the Earth,” Pepe adds. “It would then be the smallest planet ever measured using the radial velocity method.”
Maybe the least extraordinary element of the discovery of a tiny companion planet would be the fact that ESPRESSO was able to make it. Since it began operations in 2017, the spectrometer has met its developers’ expectations and exceeded them.
The progress made by the instrument reflects the burgeoning leaps made in the science of exoplanet hunting — afield still in its infancy. Since the discovery of the first exoplanet around a Sun-like star in 1995 the exoplanet-catalogue has exploded with thousands of examples.
And with the launch of ESO’s CHEOPS satellite last year and the forthcoming development of the James Webb Space Telescope and the Extremely Large Telescope, it is likely the most exciting developments are still to come.
Michel Mayor, co-winner of the 2019 Nobel Prize in physics for his discovery of the first exoplanet around a Sun-like star with Didier Queloz in 1995, is one of the architects of the ESPRESSO project. Even he is impressed with the spectrograph’s latest performance.
“ESPRESSO has made it possible to measure the mass of the planet with a precision of over one-tenth of the mass of Earth,” concludes Mayor, honorary professor in the University of Geneva’s Faculty of Science. “It’s completely unheard of.”
This article was originally published on The Cosmic Companion by Robert Lea. You can read this original piece here.
Astronomy News with The Cosmic Companion is also available as a weekly podcast, carried on all major podcast providers. Tune in every Tuesday for updates on the latest astronomy news, and interviews with astronomers and other researchers working to uncover the nature of the Universe.
