{"id":797933,"date":"2025-08-27T10:00:19","date_gmt":"2025-08-27T15:00:19","guid":{"rendered":"https:\/\/spaceweekly.com\/?p=797933"},"modified":"2025-08-27T10:00:19","modified_gmt":"2025-08-27T15:00:19","slug":"star-spots-and-planetary-transits-on-distant-stars","status":"publish","type":"post","link":"https:\/\/spaceweekly.com\/?p=797933","title":{"rendered":"Star spots and planetary transits on distant stars"},"content":{"rendered":"<p> <br \/>\n<\/p>\n<div>\n<figure id=\"attachment_519880\" aria-describedby=\"caption-attachment-519880\" style=\"width: 800px\" class=\"wp-caption alignnone\"><figcaption id=\"caption-attachment-519880\" class=\"wp-caption-text\">Artist\u2019s concept of the varying brightness of a star with a transiting planet and several star spots. Image via NASA\/ Goddard Space Flight Center.<\/figcaption><\/figure>\n<ul>\n<li><strong>NASA is using a new method<\/strong>, StarryStarryProcess, to map star spots. It shows stars with dark, spotty surfaces.<\/li>\n<li><strong>This method reveals<\/strong> the number, location and brightness of star spots and combines transit data with star rotation for better accuracy.<\/li>\n<li><strong>This process <\/strong>will help scientists study exoplanets more accurately.<\/li>\n<\/ul>\n<h3>New method to map distant stars<\/h3>\n<p>Scientists have devised a new method for mapping the spottiness of distant stars. They are using observations from NASA missions to detect orbiting planets crossing their stars\u2019 faces. The model builds on a technique researchers have used for decades to study star spots.<\/p>\n<p>By improving astronomers\u2019 understanding of spotty stars, the new model \u2013 called StarryStarryProcess \u2013 can help gather more information. It can study planetary atmospheres and potential habitability using data from telescopes like NASA\u2019s upcoming Pandora mission.<\/p>\n<p>Sabina Sagynbayeva, a graduate student at Stony Brook University in New York, said:<\/p>\n<blockquote>\n<p>Many of the models researchers use to analyze data from exoplanets, or worlds beyond our solar system, assume that stars are uniformly bright disks. But we know just by looking at our own sun that stars are more complicated than that. Modeling complexity can be difficult, but our approach gives astronomers an idea of how many spots a star might have, where they are located and how bright or dark they are.<\/p>\n<\/blockquote>\n<p>A paper describing StarryStarryProcess, led by Sagynbayeva, was published Monday, August 25, 2025, in <em>The Astrophysical Journal<\/em>.<\/p>\n<p><iframe loading=\"lazy\" title=\"Mapping Stellar &#039;Polka Dots&#039;\" width=\"1110\" height=\"624\" src=\"https:\/\/www.youtube.com\/embed\/9xvH4hq7EZQ?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/p>\n<h3>Planets identified from stellar transits<\/h3>\n<p>NASA\u2019s TESS (Transiting Exoplanet Survey Satellite) and now-retired Kepler Space Telescope were designed to identify planets using transits. Any time a planet passes in front of a star, it results in a dip in stellar brightness.<\/p>\n<p>These measurements reveal how the star\u2019s light varies with time during each transit. And astronomers can arrange them in a plot astronomers call a light curve. Typically, a transit light curve traces a smooth sweep down as the planet starts passing in front of the star\u2019s face. It reaches a minimum brightness when the world is fully in front of the star. Then finally, it rises smoothly as the planet exits and the transit ends.<\/p>\n<p>By measuring the time between transits, scientists can determine how far the planet lies from its star and estimate its surface temperature. The amount of missing light from the star during a transit can reveal the planet\u2019s size, which can hint at its composition.<\/p>\n<h3>And then there\u2019s star spots<\/h3>\n<p>Every now and then, though, a planet\u2019s light curve appears more complicated, with smaller dips and peaks added to the main arc. Scientists think these represent dark surface features akin to sunspots seen on our own sun: star spots.<\/p>\n<p>Our sun\u2019s total number of sunspots varies as it goes through its 11-year solar cycle. Scientists use them to determine and predict the progress of that cycle as well as outbreaks of solar activity that could affect us here on Earth.<\/p>\n<p>Similarly, star spots are cool, dark, temporary patches on a stellar surface whose sizes and numbers change over time. Their variability impacts what astronomers can learn about transiting planets.<\/p>\n<h3>Using planetary transits<\/h3>\n<p>Scientists have previously analyzed transit light curves from exoplanets and their host stars to look at the smaller dips and peaks. This helps determine the host star\u2019s properties, such as its overall level of spottiness, the inclination angle of the planet\u2019s orbit, the tilt of the star\u2019s spin compared to our line of sight, and other factors. Sagynbayeva\u2019s model uses light curves that include not only transit information, but also the rotation of the star itself. This provides even more detailed information about these stellar properties.<\/p>\n<p>Co-author Brett Morris, a senior software engineer at the Space Telescope Science Institute in Baltimore, said: <\/p>\n<blockquote>\n<p>\nKnowing more about the star in turn helps us learn even more about the planet, like a feedback loop. For example, at cool enough temperatures, stars can have water vapor in their atmospheres. If we want to look for water in the atmospheres of planets around those stars \u2013 a key indicator of habitability \u2013 we better be very sure that we\u2019re not confusing the two.<\/p>\n<\/blockquote>\n<h3>A transit was observed on a gas giant planet<\/h3>\n<p>To test their model, Sagynbayeva and her team looked at transits from a planet called TOI 3884 b. It\u2019s located around 141 light-years away in the constellation Virgo the Maiden.<\/p>\n<p>Discovered by TESS in 2022, astronomers think the planet is a gas giant about five times bigger than Earth and 32 times its mass.<\/p>\n<p>The StarryStarryProcess analysis suggests that the planet\u2019s cool, dim star \u2013 called TOI 3384 \u2013 has concentrations of spots at its north pole. Its north pole also tips toward Earth so that the planet passes over the pole from our perspective.<\/p>\n<p>Currently, the only available data sets that can be fit by Sagynbayeva\u2019s model are in visible light, which excludes infrared observations taken by NASA\u2019s James Webb Space Telescope. But NASA\u2019s upcoming Pandora mission will benefit from tools like this one. Pandora, a small satellite developed through NASA\u2019s Astrophysics Pioneers Program, will study the atmospheres of exoplanets and the activity of their host stars. It\u2019ll take long-duration multi-wavelength observations. The Pandora mission\u2019s goal is to determine how the properties of a star\u2019s light differs when it passes through a planet\u2019s atmosphere so scientists can better measure those atmospheres using Webb and other missions.<\/p>\n<h3>Future studies<\/h3>\n<p>Allison Youngblood, TESS project scientist at NASA\u2019s Goddard Space Flight Center in Greenbelt, Maryland, said:<\/p>\n<blockquote>\n<p>The TESS satellite has discovered thousands of planets since it launched in 2018. While Pandora will study about 20 worlds, it will advance our ability to pick out which signals come from stars and which come from planets. The more we understand the individual parts of a planetary system, the better we understand the whole system, and our own.<\/p>\n<\/blockquote>\n<p>Bottom line: NASA scientists use a new method with TESS and Kepler data to map star spots on distant stars to enhance our understanding of stellar activity and exoplanets.<\/p>\n<p>Via NASA\u2019s Goddard Space Flight Center<\/p>\n<p>Read more: Our 1st 3D weather map from a distant exoplanet<\/p>\n<p><span class=\"cp-load-after-post\"\/><\/div>\n<div>\n<div class=\"post-author\">\n<h4>EarthSky Voices<\/h4>\n<p>                    View Articles\n                  <\/p><\/div>\n<div class=\"post-tags\">\n<h6 data-udy-fe=\"text_7c58270d\">About the Author:<\/h6>\n<p>Members of the EarthSky community &#8211; including scientists, as well as science and nature writers from across the globe &#8211; weigh in on what&#8217;s important to them.<\/p>\n<\/p><\/div>\n<\/p><\/div>\n<p><br \/>\n<br \/><a href=\"https:\/\/earthsky.org\/space\/stellar-star-spots-planetary-transits-on-distant-stars\/?rand=772280\">Source link <\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Artist\u2019s concept of the varying brightness of a star with a transiting planet and several star spots. Image via NASA\/ Goddard Space Flight Center. NASA is using a new method,&hellip; <\/p>\n","protected":false},"author":1,"featured_media":797934,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[46],"tags":[],"class_list":["post-797933","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-earth-sky"],"_links":{"self":[{"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/posts\/797933","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=797933"}],"version-history":[{"count":0,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/posts\/797933\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/media\/797934"}],"wp:attachment":[{"href":"https:\/\/spaceweekly.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=797933"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=797933"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=797933"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}