{"id":790197,"date":"2024-10-11T06:26:52","date_gmt":"2024-10-11T11:26:52","guid":{"rendered":"https:\/\/spaceweekly.com\/?p=790197"},"modified":"2024-10-11T06:26:52","modified_gmt":"2024-10-11T11:26:52","slug":"proxima-centauri-discovered-109-years-ago","status":"publish","type":"post","link":"https:\/\/spaceweekly.com\/?p=790197","title":{"rendered":"Proxima Centauri discovered 109 years ago"},"content":{"rendered":"
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\nOur sun\u2019s closest neighbors among the stars, including Proxima Centauri. Image via NASA PhotoJournal.<\/figcaption><\/figure>\n
Discovery of Proxima Centauri announced in 1915<\/h3>\n
October 12, 1915.<\/strong> On this date, the Scottish-born astronomer Robert Innes, at the Union Observatory in Johannesburg, South Africa, announced the discovery of what we now know as the nearest star to our sun. That star is Proxima Centauri, one of three known stars in the Alpha Centauri system, with the other two stars being Alpha Centauri A and B. He announced his discovery in a paper dated October 12, 1915, titled A Faint Star of Large Proper Motion.<\/p>\n
Formerly, before this announcement, astronomers believed that Alpha Centauri was the closest star to our solar system.<\/p>\n
However, Proxima \u2013 a relatively small red dwarf star \u2013 is closer at a distance of about 4.24 light-years. Conversely, Alpha Centauri lies 4.36 light-years away.<\/p>\n
Mark your calendars\u2014Mondays and Fridays at 12:15 p.m. CDT, tune in to our YouTube livestreams! From cosmic discoveries to solar updates, there\u2019s so much to explore. Help us keep this momentum by matching our $50,000 gift. Every bit counts!<\/p>\nAnother 2-dimensional chart showing the distance to the Alpha Centauri system \u2013 including Proxima Centauri \u2013 in light-years. Image via ESO. Used with permission.<\/figcaption><\/figure>\n
The 100-year-anniversary celebration<\/h3>\n
By the way, SAASTA \u2013 the South African Agency for Science and Technology Advancement \u2013 celebrated Proxima\u2019s centenary in 2015. And at its website, SAASTA explained:<\/p>\n
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Although Innes had thoroughly observed Alpha Centauri, with his vast experience and passion for observing double stars he suspected that Alpha Centauri might have a companion. Innes compared photographic plates taken five years apart and observed that a certain faint star had moved. He found that this movement was about the same as that of Alpha Centauri.<\/p>\n
After further investigation, he concluded that it was closer to the sun than Alpha. In 1917 he proposed the new star should be called Proxima Centauri, proxima being the Latin word for \u2018nearest.\u2019<\/p>\n<\/blockquote>\n
Proxima Centauri has 3 known exoplanets<\/h3>\n
Today, Proxima remains the closest star to Earth, but it is too dim to see without optical aid. Also, Proxima Centauri has three confirmed planets, known as Proxima Centauri b, c and d. So these three exoplanets are the nearest planets outside our solar system. Interestingly, Proxima b orbits inside the star\u2019s habitable zone.<\/p>\nView larger. | The 2 bright stars here are Alpha and Beta Centauri. The red circle below shows the location of Proxima Centauri. It is much dimmer than its companions. Therefore, it is more difficulte to see from Earth. But, at just over one parsec away, it is the closest star to our sun. Also, sitting in the southern constellation Centaurus the Centaur, it is most likely gravitationally bound to the bright star on the right: Alpha Centauri. Image via Skatebiker\/ Wikimedia Commons\/ CC Share Alike 3.0.<\/figcaption><\/figure>\n
Bottom line: October 12, 1915, was the date of the publication of a paper announcing that the little star Proxima Centauri \u2013 in the Alpha Centauri system \u2013 is the nearest star to our sun.<\/p>\n
Read more: Alpha Centauri planets? TOLIMAN will search<\/p>\n
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Deborah Byrd<\/h4>\n
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About the Author:<\/h6>\n
Our Editor-in-Chief Deborah Byrd works to keep all the astronomy balls in the air between EarthSky’s website, YouTube page and social media platforms. She’s the primary editor of our popular daily newsletter and a frequent host of EarthSky livestreams. Deborah created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Prior to that, she had worked for the University of Texas McDonald Observatory since 1976, and created and produced their Star Date radio series. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. In 2020, she won the Education Prize from the American Astronomical Society, the largest organization of professional astronomers in North America. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. “Being an EarthSky editor is like hosting a big global party for cool nature-lovers,” she says.<\/p>\n<\/p><\/div>\n<\/p><\/div>\n
![\"Chart](\"https:\/\/earthsky.org\/upl\/2023\/10\/Distance-to-Alpha-Centauri-system-ESO.jpg\")
![\"Dense](\"https:\/\/earthsky.org\/upl\/2012\/12\/640px-Alpha_Beta_and_Proxima_Centauri-e1444661729572.jpg\")