The planet, called AF Lep b, is among the first ever discovered using a technique called astrometry; this method measures the subtle movements of a host star over many years to help astronomers determine whether hard-to-see orbiting companions, including planets, are gravitationally tugging at it.
The study, led by astronomy graduate student Kyle Franson at the University of Texas at Austin (UT Austin), is published in Thrusday's issue of Astrophysical Journal Letters.
"When we processed the observations using the Keck II telescope in real time to carefully remove the glare of the star, the planet immediately popped out and became increasingly apparent the longer we observed," said Franson.
The direct images Franson's team captured revealed that AF Lep b is about three times the mass of Jupiter and orbits AF Leporis, a young Sun-like star about 87.5 light-years away. They took a series of deep images of the planet starting in December 2021; two other teams also captured images of the same planet since then.
"This is the first time this method has been used to find a giant planet orbiting a young analog of the Sun," said Brendan Bowler, an assistant professor of astronomy at UT Austin and senior author on the study. "This opens the door to using this approach as a new tool for exoplanet discovery."
Despite having a much smaller mass than its host star, an orbiting planet causes a star's position to wobble slightly around the center of mass of the planetary system. Astrometry uses this shift in a star's position on the sky relative to other stars to infer the existence of orbiting planets. Franson and Bowler identified the star AF Leporis as one that might harbor a planet, given the way it had moved during 25 years of observations from the Hipparcos and Gaia satellites.
To directly image the planet, the UT Austin team used Keck Observatory's adaptive optics system, which corrects for fluctuations caused by turbulence in Earth's atmosphere, paired with the Keck II Telescope's Near-Infrared Camera 2 (NIRC2) Vector Vortex Coronagraph, which suppresses light from the host star so the planet could be seen more clearly. AF Lep b is about 10,000 times fainter than its host star and is located about 8 times the Earth-Sun distance.
"Imaging planets is challenging," Franson said. "We only have about 15 examples, and we think this new 'dynamically informed' approach made possible by the Keck II telescope and NIRC2 adaptive optics imaging will be much more efficient compared to blind surveys which have been carried out for the past two decades."
The two most common ways of finding extrasolar planets involve observing slight, periodic dimming of the starlight if a planet happens to regularly pass in front of the star- like a moth spiraling around a porch light - and measuring minute changes in the frequencies of starlight that result from the planet tugging the star back and forth along the direction to Earth. Both methods tend to work best with large planets orbiting close to their host stars, and both methods are indirect: we don't see the planet, we only see how it influences the star.
The method of combining direct imaging with astrometry could help astronomers find extrasolar planets that were hard to find before with other methods because they were too far from their host star, were too low mass, or didn't have orbits that were edge-on as seen from Earth. Another benefit of this technique is that it allows astronomers to directly measure a planet's mass, which is difficult with other methods at wide orbital distances.
Bowler said the team plans to continue studying AF Lep b.
"This will be an excellent target to further characterize with the James Webb Space Telescope and the next generation of large ground-based telescopes like the Giant Magellan Telescope and the Thirty Meter Telescope," Bowler said. "We're already planning more sensitive follow-up efforts at longer wavelengths to study the physical properties and atmospheric chemistry of this planet."
|Subscribe Free To Our Daily Newsletters
Virgin Galactic's use of the 'Overview Effect' to promote space tourism is a terrible irony
Diving into practice
Schools, museums, libraries can apply to receive artifacts from NASA
Catastrophic failure assessment of sealed cabin for ultra large manned spacecraft
Final launch of Europe's Ariane 5 rocket postponed
Top Secret NRO Spy Satellite launched on ULA's Delta IV Heavy Penultimate Flight
VAST selects Impulse Space for Haven-1 Space Station Propulsion
Upgrades to KSC ground systems near completion for Artemis II
Rover on the home stretch to the Martian moon Phobos
Continuing along the alternate route: Sols 3861-3864
Persevering across the upper fan in search of record-keeping rocks
Touch and Go: Sol 3865
Tianzhou 5 reconnects with Tiangong space station
China questions whether there is a new moon race afoot
Three Chinese astronauts return safely to Earth
Scientific experimental samples brought back to Earth, delivered to scientists
Seven US companies collaborate with NASA to advance space capabilities
Iridium proposes a new model for monitored BVLOS UAS integration
Satellite Internet fills holes in global connectivity, but cost remains an issue
Intelsat to extend life of four satellites by 2027
SpaceLogistics continues satellite life-extension work with latest sale
China conducts extravehicular radiation biological exposure experiment on space station
Augmented reality integration used for T-50 platform
Mitsubishi Electric demonstrates light source module for high-capacity laser links
Searching for an atmosphere on the rocky exoplanet TRAPPIST-1 c
Evidence of the amino acid tryptophan found in space
Gemini North detects multiple heavier elements in atmosphere of hot Exoplanet
Photosynthesis, key to life on Earth, starts with a single photon
Juno captures lightning bolts above Jupiter's north pole
Unveiling Jupiter's upper atmosphere
ASU study: Jupiter's moon Europa may have had a slow evolution
Colorful Kuiper Belt puzzle solved by UH researchers
|Subscribe Free To Our Daily Newsletters