{"id":26172,"date":"2021-11-18T11:30:29","date_gmt":"2021-11-18T11:30:29","guid":{"rendered":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/?post_type=purple_issue&p=26172"},"modified":"2021-11-18T11:30:29","modified_gmt":"2021-11-18T11:30:29","slug":"star-of-the-month-3","status":"publish","type":"post","link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/2021\/11\/18\/star-of-the-month-3\/","title":{"rendered":"Star of the month"},"content":{"rendered":"\n

Spot Mintaka at the top of Orion\u2019s Belt<\/p>\n\n

\"\"
There\u2019s far more to the multiple star Mintaka than meets the naked eye<\/figcaption><\/figure><\/div>\n\n

Mintaka (Delta (\u03b4) Orionis) is easy to find. Shining at mag. +2.3, it marks the northwest end of Orion\u2019s Belt, the star\u2019s name deriving from the Arabic for \u2018belt\u2019. Sitting 17 arcminutes south of the celestial equator, Mintaka hides a great deal of complexity. Observations made by Johannes Franz Hartmann in 1904, using photographs taken at the Potsdam Observatory in Germany, showed Mintaka was a spectroscopic binary.<\/p>\n\n

A spectroscopic binary shows periodic movement within its component star\u2019s spectral lines. Hartmann noticed the Calcium-K line at 393.34 nanometres didn\u2019t show the same periodicity as the Mintakan system and from this he deduced there must be a calcium cloud between us and the star. This was the first detection of what\u2019s known as the interstellar medium.<\/span><\/p>\n\n

Mintaka is a complex multiple star, comprising a mag. +6.8 star 52 arcseconds to the north of the primary and a far fainter 14th magnitude star in between. The mag. +2.3 primary is designated A, the 14th magnitude star is B and the mag. +6.8 star C.<\/p>\n\n

Delta (\u03b4) Orionis A is the spectroscopic binary, an O9.5 II giant (Aa1) and B1 V main sequence star (Aa2) in a 5.73- day orbit. A B0 IV subgiant (Ab) sits 0.26 arcseconds from the spectroscopic pair. The 14th magnitude companion (B) is a cool star, about 70 per cent the size of our Sun and around 40 per cent as luminous. The seventh<\/span> magnitude companion (C) is another spectroscopic binary comprising an A-type primary and B-type companion in a 30-day orbit.<\/p>\n","protected":false},"excerpt":{"rendered":"

Spot Mintaka at the top of Orion\u2019s Belt<\/p>\n","protected":false},"author":24,"featured_media":26171,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"ub_ctt_via":"","purple_page_number":"53","purple_custom_meta_purple_page_number":"53","purple_seq_number":"3","purple_custom_meta_purple_seq_number":"3","purple_source_article":"article_53-3.xml","purple_custom_meta_purple_source_article":"article_53-3.xml","purple_source_issue":"December-2021","purple_custom_meta_purple_source_issue":"December-2021","purple_external_id":"December-2021-53-3","purple_custom_meta_purple_external_id":"December-2021-53-3","purple_issue_code":"|0000086547||","purple_custom_meta_purple_issue_code":"|0000086547||","purple_android_product":"com.im.skyatnight.199","purple_custom_meta_purple_android_product":"com.im.skyatnight.199","purple_ios_product":"com.im.skyatnight.199","purple_custom_meta_purple_ios_product":"com.im.skyatnight.199","purple_web_product":"","purple_custom_meta_purple_web_product":"","purple_publication_id":"075fab74-0a21-4201-866a-899d6c41c40c","purple_migrated":"","kt_blocks_editor_width":""},"categories":[22],"tags":[14],"featured_image_src":"https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2021\/11\/5f34e39e-5c90-41e9-b48b-2ee42c81dd84.jpg","author_info":{"display_name":"importmanagerhub@sprylab.com","author_link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/author\/importmanagerhubsprylab-com\/"},"acf":{"readingTimeMinutes":"2","apple_news_title":""},"uagb_featured_image_src":{"full":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2021\/11\/5f34e39e-5c90-41e9-b48b-2ee42c81dd84.jpg",1032,876,false],"thumbnail":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2021\/11\/5f34e39e-5c90-41e9-b48b-2ee42c81dd84-150x150.jpg",150,150,true],"medium":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2021\/11\/5f34e39e-5c90-41e9-b48b-2ee42c81dd84-300x255.jpg",300,255,true],"medium_large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2021\/11\/5f34e39e-5c90-41e9-b48b-2ee42c81dd84-768x652.jpg",768,652,true],"large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2021\/11\/5f34e39e-5c90-41e9-b48b-2ee42c81dd84-1024x869.jpg",800,679,true],"1536x1536":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2021\/11\/5f34e39e-5c90-41e9-b48b-2ee42c81dd84.jpg",1032,876,false],"2048x2048":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2021\/11\/5f34e39e-5c90-41e9-b48b-2ee42c81dd84.jpg",1032,876,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":"Spot Mintaka at the top of Orion\u2019s Belt","_links":{"self":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/26172"}],"collection":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/users\/24"}],"replies":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/comments?post=26172"}],"version-history":[{"count":2,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/26172\/revisions"}],"predecessor-version":[{"id":26555,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/26172\/revisions\/26555"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media\/26171"}],"wp:attachment":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media?parent=26172"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/categories?post=26172"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/tags?post=26172"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}