NOIRLab: MAROON-X Embarks on its Exoplanet Quest
Colorized 2D spectra of the star Gliese 486 as seen with MAROON-X. The two spectra are from the two camera arms of MAROON-X. Each spectrum covers the 500–670 nm wavelength range and the color-coding corresponds to how a human eye would perceive the colors. Credit: International Gemini Observatory/NOIRLab/NSF/AURA/A. Seifahrt
Powerful new instrument at Gemini North helps measure properties of nearby exoplanet
Astronomers using the recently installed instrument MAROON-X on Gemini North have determined the mass of a transiting exoplanet orbiting the nearby star Gliese 486. As well as putting the innovative new instrument through its paces, this result, when combined with data from the TESS satellite, precisely measures key properties of a rocky planet that is ideal for follow-up observations with the next generation of ground- and space-based telescopes.
The exoplanet-hunting instrument MAROON-X has obtained its first scientific result from its new home at the 8.1-meter Gemini North telescope, part of the international Gemini Observatory, a program of NSF’s NOIRLab [1]. Shipped from the University of Chicago in mid-2019, the instrument arrived at Gemini in a collection of wooden packing crates. Despite exhausting 12-hour shifts in the thin air at an altitude of 4300 meters (14,000 feet), the MAROON-X team successfully constructed and installed the instrument in a six-month process known as commissioning. The assembled instrument takes advantage of Gemini North’s location on Maunakea in Hawai‘i — one of the best observing sites on the planet.
“It’s been an intense six-month stretch,” explained Jacob Bean, head of the University of Chicago team behind MAROON-X. “We’ve spent ten years developing the instrument and with MAROON-X now installed on Gemini we will start to get real insights into habitable worlds around other stars.”
The technical core of MAROON-X lies at the end of a bundle of fibers trailing from behind the main mirror of Gemini North to a small room several floors below. Inside this temperature-controlled room and encased in a vacuum chamber, a collection of high-precision optical devices forms the spectrometer at the heart of MAROON-X. This spectrometer measures variations in the light from distant stars to detect the subtle influence of orbiting worlds — making MAROON-X an outstanding exoplanet hunter [2].
MAROON-X’s first science result determined the mass of the newly discovered rocky planet Gliese 486 b, which orbits Gliese 486, a star smaller and dimmer than our own Sun [3]. The planet has a mass roughly three times that of the Earth, but has a similar density. The composition of this newly discovered exoplanet is not its only distinguishing feature — its relative closeness to Earth makes it an ideal candidate for observations with the next generation of astronomical technology.