NASA\u2019s latest planet-hunting probe has discovered its first Earth-sized exoplanet orbiting a star 53 light-years away. The Transiting Exoplanets Survey Satellite also discovered a warm sub-Neptune-sized world in the same system, according to a study published in the Astrophysical Journal Letters.<\/p>\n\n\n\n
\u201cIt\u2019s so exciting that TESS, which launched just about a\n year ago, is already a game-changer in the planet-hunting business,\u201d \nsaid Johanna Teske, Carnegie Institution for Science in the US.<\/p>\n\n\n\n
The\n PFS works using a technique called the radial velocity method, which is\n currently the only way for astronomers to measure the masses of \nindividual planets. Without known masses, it is very challenging to \ndetermine a planet\u2019s density or its general chemical composition.<\/p>\n\n\n\n
This\n method takes advantage of that fact that not only does a star\u2019s gravity\n influence the planet orbiting it, but the planet\u2019s gravity also affects\n the star in turn. The PFS enables astronomers to detect these tiny \nwobbles that the planet\u2019s gravity induces in the star\u2019s orbit.<\/p>\n\n\n\n
\u201cThe\n spacecraft surveys the sky and we collaborate with the TESS follow-up \ncommunity to flag potentially interesting targets for additional \nobservations using ground-based telescopes and instruments,\u201d Teske said \nin a statement. One such tool, the Planet Finder Spectrograph on the \nMagellan II telescope in Chile, was a crucial component of this effort. \nIt helped confirm the planetary nature of the TESS signal, and to \nmeasure the mass of the newly discovered sub-Neptune.<\/p>\n\n\n\n
\u201cPFS is one\n of the only instruments in the Southern Hemisphere that can do these \ntypes of measurements. So, it will be a very important part of further \ncharacterising the planets found by the TESS mission,\u201d Teske added. With\n an orbit that takes about 36 days to complete, the sub-Neptune, HD \n21749b, has the longest period of any of the TESS discoveries published \nso far, researchers said. Its host star has about 80 per cent of the \nmass of our Sun and is found about 53 light-years distant from Earth. HD\n 21749b has about 23 times Earth\u2019s mass and a radius of about 2.7 times \nEarth\u2019s. Its density indicates the planet has substantial atmosphere but\n is not rocky, so it could potentially help astronomers understand the \ncomposition and evolution of cooler sub-Neptune planet atmospheres.<\/p>\n\n\n\n
The\n longer period sub-Neptune planet in this system is not alone. It has a \nsibling planet, HD 21749c, which takes about eight days to orbit the \nhost star and is much smaller similar in size to Earth.\n\n<\/p>\n","protected":false},"excerpt":{"rendered":"
NASA\u2019s latest planet-hunting probe has discovered its first Earth-sized exoplanet orbiting a star 53 light-years away. The Transiting Exoplanets Survey Satellite also discovered a warm sub-Neptune-sized world in the same system, according to a study published in the Astrophysical Journal Letters. \u201cIt\u2019s so exciting that TESS, which launched just about a year ago, is already […]<\/p>\n","protected":false},"author":1,"featured_media":59333,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"inline_featured_image":false,"footnotes":""},"categories":[87],"tags":[],"class_list":["post-59332","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-world"],"_links":{"self":[{"href":"https:\/\/blastingskyhawk.com\/english\/wp-json\/wp\/v2\/posts\/59332","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blastingskyhawk.com\/english\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blastingskyhawk.com\/english\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blastingskyhawk.com\/english\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blastingskyhawk.com\/english\/wp-json\/wp\/v2\/comments?post=59332"}],"version-history":[{"count":1,"href":"https:\/\/blastingskyhawk.com\/english\/wp-json\/wp\/v2\/posts\/59332\/revisions"}],"predecessor-version":[{"id":59334,"href":"https:\/\/blastingskyhawk.com\/english\/wp-json\/wp\/v2\/posts\/59332\/revisions\/59334"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blastingskyhawk.com\/english\/wp-json\/wp\/v2\/media\/59333"}],"wp:attachment":[{"href":"https:\/\/blastingskyhawk.com\/english\/wp-json\/wp\/v2\/media?parent=59332"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blastingskyhawk.com\/english\/wp-json\/wp\/v2\/categories?post=59332"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blastingskyhawk.com\/english\/wp-json\/wp\/v2\/tags?post=59332"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}