The James Webb Space Telescope has directly imaged Epsilon Indi Ab, a cold Jupiter-like exoplanet 12 light-years from Earth. This discovery is significant because it provides insight into the properties of the atmosphere of a planet that is colder than most known exoplanets, helping to improve our understanding of planetary systems beyond Earth. (Artist’s concept) Credit: SciTechDaily.com
Epsilon Indi Ab is the coldest planet ever photographed outside our solar system.
If an alien astronomer living in a nearby star system National Aeronautics and Space Administration (NASA)of James Webb Space TelescopeAnd they pointed it out into the solar system. Jupiter It may look very similar to this new Webb image. Exoplanets Epsilon Indi Ab. One of the coolest exoplanets ever directly detected, with an estimated temperature of 35 °C. Fahrenheit (2 degrees Celsius). Epsilon Indi Ab’s temperature is only about 180 degrees Fahrenheit (100 degrees Celsius) warmer than the gas giants in our solar system. Because there are many known exoplanets that are completely dissimilar to planets in our solar system, Epsilon Indi Ab provides astronomers with a unique opportunity to study the atmospheric composition of true solar system analogues.
This image of gas giant Epsilon Indi Ab was taken with the MIRI (Mid-Infrared Instrument) coronagraph on NASA’s James Webb Space Telescope. The star symbol marks the location of the host star Epsilon Indi A, whose light is blocked by the coronagraph, resulting in a dark circle marked by a dashed white line. Epsilon Indi Ab is one of the coolest exoplanets ever directly imaged. Light at 10.6 microns is assigned the color blue, and light at 15.5 microns the color orange. MIRI did not resolve the planet, which is a point source. Credit: NASA, ESA, CSA, STScI, Elizabeth Matthews (MPIA)
Webb Space Telescope captures cold exoplanet 12 light years away
An international team of astronomers used NASA’s James Webb Space Telescope to directly image an exoplanet about 12 light-years from Earth. The planet, Epsilon Indi Ab, is one of the coolest exoplanets ever observed.
The planet is several times more massive than Jupiter and orbits a K-type star called Epsilon Indi A, which is roughly the same age as the Sun but slightly cooler than it. The team observed Epsilon Indi Ab using Webb’s coronagraph. Milli (mid-infrared instruments). To date, only a few dozen exoplanets have been directly imaged by space or ground-based observatories.
“Previous observations of this system have been indirect measurements of the star, so we knew in advance that it was likely to have a giant planet tugging at the star,” said team member Caroline Morley of the University of Texas at Austin, “which is why our team chose this system as the first one to observe with Webb.”
“This discovery is really intriguing because the planet is so similar to Jupiter — it’s a bit warmer and more massive, but it’s more similar to Jupiter than any planet imaged so far,” added lead author Elisabeth Matthews of the Max Planck Institute for Astronomy in Germany.
Since its launch in 2021, the James Webb Space Telescope has used its advanced infrared capabilities and large mirrors to peer into the universe’s earliest moments, providing detailed insights into galaxies, stars, and exoplanets, greatly enhancing our understanding of the cosmos. Credit: NASA
Solar System Analogues
The exoplanets imaged so far tend to be the youngest and hottest, still radiating much of the energy they had when they first formed. As the planets cool and contract over their lifetimes, they become significantly fainter, making them harder to image.
“Cool planets are very dark and most of their radiation is in the mid-infrared,” Matthews explains. “Webb is ideal for mid-infrared imaging, which is very difficult to do from the ground. We also needed good spatial resolution to distinguish planets from stars in the images, and Webb’s large mirror helps a lot in this regard.”
Epsilon Indi Ab is one of the coolest directly detected exoplanets, with an estimated temperature of 35 degrees Fahrenheit (2 degrees Celsius). This makes it cooler than any imaged planet outside our solar system and cooler than all but one free-floating brown dwarf. The planet is only about 180 degrees Fahrenheit (100 degrees Celsius) hotter than the gas giants in our solar system. This provides astronomers with a rare opportunity to study the atmospheric composition of a true solar-like planet.
“Astronomers have imagined there could be a planet in this system for decades, and fictional planets orbiting Epsilon Indi have been the setting for Star Trek episodes, novels, and video games like Halo,” Morley added. “It’s exciting to see for ourselves that there is actually a planet there and to begin measuring its properties.”
Not as expected
Epsilon Indi Ab is the 12th closest exoplanet currently known to Earth and the closest planet with a mass greater than Jupiter. The science team chose Epsilon Indi A to study because the system had indicated the possibility of a planetary body using a technique called “Epsilon Indi A.” Radial velocityThis measures the way the primary star swings back and forth along our line of sight.
“We were hoping to image a planet in this system, as the radial velocity suggested the presence of one, but the planet we found was different to what we expected,” said Matthews. “It has about twice the mass we expected, is a bit farther from the star, and is in a different orbit than expected. We don’t yet know what causes this discrepancy. The planet’s atmosphere also seems to be a bit different than model predictions. Only a few atmospheric photometry measurements have been made so far, making it difficult to draw any conclusions, but the planet appears to be fainter than expected at shorter wavelengths.”
The team believes this suggests the planet’s atmosphere may have large amounts of methane, carbon monoxide, and carbon dioxide that absorb short wavelengths of light, and may also have a very cloudy atmosphere.
Direct imaging of exoplanets is especially valuable for characterization: it allows scientists to directly collect light from the planet they are observing and compare its brightness at different wavelengths. So far, the science team has only detected Epsilon Indi Ab at a few wavelengths, but they hope to revisit the planet with Webb and conduct both photometry and observations. Spectroscopic observations In the future, they also hope to use Webb to detect other similar planets and discover trends in their atmospheres and how these objects formed.
NASA’s next Nancy Grace Roman Space Telescope Use the Coronagraph “We are demonstrating our direct imaging technique by photographing a Jupiter-like world orbiting a Sun-like star, something that has never been done before. These results will pave the way for future missions to study even more Earth-like worlds.”
These results were obtained during Webb’s Cycle 1 General Observation Program 2243 and published in the journal Nature.
For more information on this discovery, JWST’s Super-Jupiter Exploration Breakthrough: Oldest, Coldest Exoplanet Ever Photographed.
Reference: “A temperate superjupiter imaged in mid-infrared by JWST,” E. C. Matthews, A. L. Carter, P. Pathak, C. V. Morley, M. W. Phillips, S. Krishanth P. M, F. Feng, M. J. Bonse, L. A. Boogaard, J. A. Burt, I. J. M. Crossfield, E. S. Douglas, Th. Henning, J. Hom, C.-L. Ko, M. Kasper, A.-M. Lagrange, D. Petit dit de la Roche, F. Philipot, 24 July 2024; Nature.
DOI: 10.1038/s41586-024-07837-8
The James Webb Space Telescope (JWST), launched on December 25, 2021, represents a groundbreaking advancement in astronomy capabilities. Hubble Space TelescopeJWST is designed to observe the Universe primarily in the infrared spectrum, allowing it to see through cosmic dust and observe the earliest moments of the Universe. With its large, segmented primary mirror spanning 6.5 meters and a suite of advanced scientific instruments, the telescope will be able to take incredibly detailed images of distant galaxies, star-forming nebulae, and exoplanets, providing unprecedented insights into the origins of stars, planetary systems, and the Universe itself. JWST is a joint venture between NASA, European Space Agency The satellite is being developed jointly by the European Space Agency (ESA) and the Canadian Space Agency (CSA) and is expected to fundamentally change our understanding of the universe.
