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\t\t\t\t\t\t24\/07\/2024<\/span> An international team of astronomers using the NASA\/ESA\/CSA James Webb Space Telescope have directly imaged an exoplanet roughly 12 light-years from Earth. While there were hints that the planet existed, it had not been confirmed until Webb imaged it. The planet is one of the coldest exoplanets observed to date.<\/p>\n<\/div>\n The planet, known Epsilon Indi Ab, is several times the mass of Jupiter and orbits the K-type star Epsilon Indi A (Eps Ind A), which is around the age of our Sun, but slightly cooler. The team observed Epsilon Indi Ab using the coronagraph on Webb\u2019s\u00a0MIRI (Mid-Infrared Instrument). Only a few tens of exoplanets have been directly imaged previously by space- and ground-based observatories.<\/p>\n \u201cThis discovery is exciting because the planet is quite similar to Jupiter \u2013\u00a0it is a little warmer and is more massive, but is more similar to Jupiter than any other planet that has been imaged so far,\u201d said lead author Elisabeth Matthews of the Max Planck Institute for Astronomy in Germany.<\/p>\n \u201cOur prior observations of this system have been more indirect measurements of the star, which actually allowed us to see ahead of time that there was likely a giant planet in this system tugging on the star,\u201d added team member Caroline Morley of the University of Texas at Austin, USA.\u00a0\u201cThat’s why our team chose this system to observe first with Webb.\u201d<\/p>\n<\/p><\/div>\n Previously imaged exoplanets tend to be the youngest, hottest exoplanets that are still radiating much of the energy from when they first formed. As planets cool and contract over their lifetime, they become significantly fainter and therefore harder to image.<\/p>\n \u201cCold planets are very faint, and most of their emission is in the mid-infrared,\u201d\u00a0explained Elisabeth.\u00a0\u201cWebb is ideally suited to conduct mid-infrared imaging, which is extremely hard to do from the ground. We also needed good spatial resolution to separate the planet and the star in our images, and the large Webb mirror is extremely helpful in this aspect.\u201d<\/p>\n Epsilon Indi Ab is one of the coldest exoplanets to be directly detected, with an estimated temperature of 2 degrees Celsius\u00a0\u2013 colder than any other imaged planet beyond our Solar System, and colder than all but one free-floating brown dwarf\u00a0[1].\u00a0The planet is only around 100 degrees Celsius warmer than gas giants in our Solar System. This provides a rare opportunity for astronomers to study the atmospheric composition of true Solar System analogues.<\/p>\n \u201cAstronomers have been imagining planets in this system for decades; fictional planets orbiting Epsilon Indi have been the sites of Star Trek episodes, novels, and video games like Halo,\u201d\u00a0added Caroline.\u00a0\u201cIt’s exciting to actually see a planet there ourselves, and begin to measure its properties.\u201d<\/p>\n<\/p><\/div>\n Epsilon Indi Ab is the twelfth closest exoplanet to Earth known to date and the closest planet more massive than Jupiter. The science team chose to study Eps Ind A because the system showed hints of a possible planetary body using a technique called radial velocity, which measures the back-and-forth wobbles of the host star along our line of sight.<\/p>\n \u201cWhile we expected to image a planet in this system, because there were radial velocity indications of its presence, the planet we found isn’t what we had predicted,\u201d\u00a0shared Elisabeth.\u201c<\/p>\n It\u2019s about twice as massive, a little farther from its star, and has a different orbit than we expected. The cause of this discrepancy remains an open question. The atmosphere of the planet also appears to be a little different than the model predictions. So far we only have a few photometric measurements of the atmosphere, meaning that it is hard to draw conclusions, but the planet is fainter than expected at shorter wavelengths.\u201d<\/p>\n The team believes this may mean there is significant methane, carbon monoxide, and carbon dioxide in the planet\u2019s atmosphere that are absorbing the shorter wavelengths of light. It might also suggest a very cloudy atmosphere.<\/p>\n The direct imaging of exoplanets is particularly valuable for characterisation. Scientists can directly collect light from the observed planet 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 to conduct both photometric [2] and spectroscopic observations in the future. They also hope to detect other similar planets with Webb to find possible trends about their atmospheres and how these objects form.<\/p>\n These results were taken with Webb\u2019s Cycle 1 GO programme #2243\u00a0and have been published in\u00a0Nature<\/i>.\u00a0<\/p>\n<\/p><\/div>\n Notes<\/b><\/p>\n \n[1]\u00a0This brown dwarf, known as Wise 0855, was\u00a0discovered in 2014, and has been\u00a0observed by Webb.<\/p>\n \n[2] Photometry is the science of measuring the amount of light received from a star.<\/p>\n \u00a0<\/p>\n More information<\/b><\/p>\n Webb\u00a0is the largest, most powerful telescope ever launched into space. Under an international collaboration agreement, ESA provided the telescope\u2019s launch service, using the Ariane 5 launch vehicle. Working with partners, ESA was responsible for the development and qualification of Ariane 5 adaptations for the Webb mission and for the procurement of the launch service by Arianespace. ESA also provided the workhorse spectrograph\u00a0NIRSpec\u00a0and 50% of the mid-infrared instrument\u00a0MIRI, which was designed and built by a consortium of nationally funded European Institutes (The MIRI European Consortium) in partnership with JPL and the University of Arizona.<\/p>\n Webb is an international partnership between NASA, ESA and the Canadian Space Agency (CSA).<\/p>\n Release on esawebb.org<\/p>\n \nContact:<\/b>
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\n\t\t\t\t\t\t\t\t\t\t0<\/span> likes<\/small><\/span><\/p>\n<\/header>\nA Solar System analog<\/h2>\n
Not quite as predicted<\/h2>\n
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