{"id":31692,"date":"2022-04-27T12:10:24","date_gmt":"2022-04-27T12:10:24","guid":{"rendered":"https:\/\/www.skyatnightmagazine.com\/?p=107866"},"modified":"2022-04-27T12:28:15","modified_gmt":"2022-04-27T12:28:15","slug":"spot-star-regulus-a-jewel-in-the-springtime-sky","status":"publish","type":"rss_feed","link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/rss_feed\/spot-star-regulus-a-jewel-in-the-springtime-sky\/","title":{"rendered":"Spot star Regulus, a jewel in the springtime sky"},"content":{"rendered":"

<\/p>

By Pete Lawrence\n \t\t<\/p>

Published: Wednesday, 27 April 2022 at 12:00 am<\/p>

\n\n

Regulus (Alpha (<\/span>\u03b1<\/span>) Leonis) is one of the principal stars of the spring sky and can easily be seen with the naked eye.<\/span><\/p>\n

It\u2019s easy to spot at the base of the Sickle asterism<\/a>, a pattern representing the head of the constellation Leo<\/a>.<\/span><\/p>\n

If you need further affirmation, follow the lines of both sides of the Plough\u2019s blade down and away from Polaris, the north star<\/a>.<\/span><\/p>\n

With a bit of artistic license, they converge at Regulus.<\/span><\/p>\n

\"""\"<\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/picture><\/div>
Credit: Pete Lawrence<\/span><\/figcaption><\/div>\n

Regulus is 79 lightyears from the Sun and appears to us at mag. +1.4, located 0.5\u00b0 from the ecliptic<\/a>.<\/span><\/p>\n

This location means that Solar System objects appear to interact with it, and it sometimes undergoes lunar occultation<\/a>.<\/span><\/p>\n

Planetary conjunctions<\/a> with Regulus aren\u2019t uncommon but planetary occultations are rare.<\/span><\/p>\n

The next planetary occultation of Regulus will occur on 1 October 2044, when Venus passes in front of the star. <\/span><\/p>\n

Regulus is a multiple star system. An obvious mag. +8.2 companion sits 177 arcseconds away in a northwest direction (position angle 307\u00b0).<\/span><\/p>\n

This orange companion, Regulus B, is a double star<\/a> with a separation of 2.5 arcseconds between it and mag. +13.5 Regulus C.<\/span><\/p>\n

The B-C pair\u2019s orbital period is an estimated 600 years.<\/span><\/p>\n

\"""\"<\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/picture><\/div>
Regulus and a parade of planets on November 8 2015 by Martin Marthadinata, Surabaya, East Java, Indonesia. Equipment: Nikon D5000<\/span><\/figcaption><\/div>\n

This pales into insignificance compared to the 125,000 years it takes B-C to orbit the main Regulus A star. <\/span><\/p>\n

Spectroscopic<\/a> analysis of Regulus A reveals that it too is a double.<\/span><\/p>\n

Its so-far-unseen companion is believed to be a white dwarf star, orbiting Regulus A once every 40.11 days at a distance of just 52 million kilometres.\u00a0<\/span><\/p>\n

Another interesting characteristic of Regulus is its fast rotation rate of 317km\/s.<\/span><\/p>\n

At this speed, Regulus will be flattened into an oblate spheroid, approximately one-third wider at the equator than its polar diameter.<\/span><\/p>\n

Its equatorial diameter is estimated to be 4.3 times that of the Sun.<\/span><\/p>\n

Observing Regulus through binoculars<\/strong><\/h2>\n
\"""\"<\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/picture><\/div>
Binoculars are a great way for newcomers to get into astronomy. Credit: lucentius \/ Getty Images<\/span><\/figcaption><\/div>\n

Most multiple stars with components of very different magnitudes are difficult to split, so it\u2019s pleasant to find an easy one!<\/p>\n

Regulus shines at mag. +1.4, nearly 500 times brighter than its companion.<\/p>\n

Fortunately, they are separated by nearly 3 arcminutes, allowing even small compact binoculars to show the companion star.<\/p>\n

We\u2019d recommend a pair of 10\u00d750 binoculars to observe Regulus.<\/p>\n

As we know, Regulus is a true multiple star system, not a chance line-of-sight pairing, which makes observing this double through binoculars even more satisfying.<\/p>\n

This guide originally appeared in the March 2018 issue of <\/strong><\/em>BBC Sky at Night Magazine<\/strong>.<\/strong><\/em><\/p><\/body><\/html>\n

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By Pete Lawrence Published: Wednesday, 27 April 2022 at 12:00 am Regulus (Alpha (\u03b1) Leonis) is one of the principal stars of the spring sky and can easily be seen with the naked eye. It\u2019s easy to spot at the base of the Sickle asterism, a pattern representing the head of the constellation Leo. If […]<\/p>\n","protected":false},"author":24,"featured_media":31693,"template":"","categories":[1],"acf":{"readingTimeMinutes":"3"},"uagb_featured_image_src":{"full":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/04\/spot-star-regulus-a-jewel-in-the-springtime-sky.jpg",1000,667,false],"thumbnail":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/04\/spot-star-regulus-a-jewel-in-the-springtime-sky-150x150.jpg",150,150,true],"medium":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/04\/spot-star-regulus-a-jewel-in-the-springtime-sky-300x200.jpg",300,200,true],"medium_large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/04\/spot-star-regulus-a-jewel-in-the-springtime-sky-768x512.jpg",768,512,true],"large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/04\/spot-star-regulus-a-jewel-in-the-springtime-sky.jpg",800,534,false],"1536x1536":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/04\/spot-star-regulus-a-jewel-in-the-springtime-sky.jpg",1000,667,false],"2048x2048":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/04\/spot-star-regulus-a-jewel-in-the-springtime-sky.jpg",1000,667,false]},"uagb_author_info":{"display_name":"importmanagerhub@sprylab.com","author_link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/author\/importmanagerhubsprylab-com\/"},"uagb_comment_info":0,"uagb_excerpt":"By Pete Lawrence Published: Wednesday, 27 April 2022 at 12:00 am Regulus (Alpha (\u03b1) Leonis) is one of the principal stars of the spring sky and can easily be seen with the naked eye. It\u2019s easy to spot at the base of the Sickle asterism, a pattern representing the head of the constellation Leo. If…","_links":{"self":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/rss_feed\/31692"}],"collection":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/rss_feed"}],"about":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/types\/rss_feed"}],"author":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/users\/24"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media\/31693"}],"wp:attachment":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media?parent=31692"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/categories?post=31692"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}