{"id":63880,"date":"2024-09-19T11:31:11","date_gmt":"2024-09-19T11:31:11","guid":{"rendered":"http:\/\/c34fc1c3-4c09-4e0c-b277-85979854c050"},"modified":"2024-09-19T11:39:43","modified_gmt":"2024-09-19T11:39:43","slug":"is-zubeneschamali-a-true-naked-eye-green-star","status":"publish","type":"rss_feed","link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/rss_feed\/is-zubeneschamali-a-true-naked-eye-green-star\/","title":{"rendered":"Is Zubeneschamali a true naked-eye green star?"},"content":{"rendered":"

<\/p>

By Pete Lawrence\n <\/p>

Published: Thursday, 19 September 2024 at 11:31 AM<\/p>

\n\n

The star Beta (\u03b2) Librae, also known as Zubeneschamali, sits at the top of the fairly indistinct constellation of Libra, the Scales.<\/p>

Libra, and therefore Zubeneschamali, is best seen in the spring and summer skies, in the northern hemisphere.<\/p>

The summer months are the best time to try to spot the ‘green’ stars Zubeneschamali, Antares, Acrab and Raslagethi, with Cor Caroli best in spring. Click to expand. Credit: Pete Lawrence<\/figcaption><\/figure>

At mag. +2.6, it is a middling brightness star that can be seen with the naked eye, meaning you don’t need binoculars or a telescope to spot it.<\/p>

Zubeneschamali means \u2018northern claw\u2019, its counterpart being mag. +2.8 Alpha (\u03b1) Librae or Zubenelgenubi<\/a>, which means \u2018southern claw\u2019.<\/p>

Although it seems odd to have two \u2018claws\u2019 in a constellation representing a set of balance scales, this makes more sense when it\u2019s revealed that Libra used to be part of neighbouring Scorpius, the Scorpion.\u00a0<\/p>

\"Chart
Chart showing a photograph of Zubeneschamali and its location in Libra. Click to expand. Credit Pete Lawrence<\/figcaption><\/figure>

Facts<\/strong><\/h2>

Zubeneschamali is a B8V dwarf star with a surface temperature around 12,300K.<\/p>

It\u2019s around 130 times more luminous and 4.9 times larger than our Sun, with 3.5 times the mass.<\/p>

It also spins over 100 times faster than the Sun, with a rotational velocity of 250 km\/s.<\/p>

At an estimated age of 80 million years, this is a hot, young star. Its temperature suggests it should shine with a blue-white colour and to most observers this is indeed the case.<\/p>

\"Photograph
Photograph of Zubeneschamali in Libra. Credit Pete Lawrence<\/figcaption><\/figure>

Is Zubeneschamali green?<\/strong><\/h2>

In the past, Zubeneschamali has been described as green in hue. If it were green, it would be the only green naked-eye star in the sky.<\/p>

Green is an odd colour for a star<\/a> because, even if a star\u2019s output were to peak in the green part of the spectrum, the narrow range of wavelengths from 500-570nm, which appear as green, are easily swamped by the wide yellow and blue wavelengths either side.<\/p>

Consequently, to the human eye, such stars tend to appear white.<\/p>

Does this star buck the trend? Pop outside and judge for yourself.<\/p>

If you observe or photograph Zubeneschamali, and have any strong opinions on whether it’s green, let us know by emailing contactus@skyatnightmagazine.com<\/a><\/em><\/strong><\/p> <\/body><\/html>\n

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By Pete Lawrence Published: Thursday, 19 September 2024 at 11:31 AM The star Beta (\u03b2) Librae, also known as Zubeneschamali, sits at the top of the fairly indistinct constellation of Libra, the Scales. Libra, and therefore Zubeneschamali, is best seen in the spring and summer skies, in the northern hemisphere. The summer months are the […]<\/p>\n","protected":false},"author":24,"featured_media":63881,"template":"","categories":[1],"acf":{"readingTimeMinutes":"2"},"uagb_featured_image_src":{"full":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2024\/09\/is-zubeneschamali-a-true-naked-eye-green-star.jpg",1200,1200,false],"thumbnail":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2024\/09\/is-zubeneschamali-a-true-naked-eye-green-star-150x150.jpg",150,150,true],"medium":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2024\/09\/is-zubeneschamali-a-true-naked-eye-green-star-300x300.jpg",300,300,true],"medium_large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2024\/09\/is-zubeneschamali-a-true-naked-eye-green-star-768x768.jpg",768,768,true],"large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2024\/09\/is-zubeneschamali-a-true-naked-eye-green-star-1024x1024.jpg",800,800,true],"1536x1536":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2024\/09\/is-zubeneschamali-a-true-naked-eye-green-star.jpg",1200,1200,false],"2048x2048":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2024\/09\/is-zubeneschamali-a-true-naked-eye-green-star.jpg",1200,1200,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: Thursday, 19 September 2024 at 11:31 AM The star Beta (\u03b2) Librae, also known as Zubeneschamali, sits at the top of the fairly indistinct constellation of Libra, the Scales. Libra, and therefore Zubeneschamali, is best seen in the spring and summer skies, in the northern hemisphere. The summer months are the…","_links":{"self":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/rss_feed\/63880"}],"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\/63881"}],"wp:attachment":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media?parent=63880"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/categories?post=63880"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}