{"id":40241,"date":"2023-01-19T11:23:54","date_gmt":"2023-01-19T11:23:54","guid":{"rendered":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/?post_type=purple_issue&p=40241"},"modified":"2023-01-19T11:23:54","modified_gmt":"2023-01-19T11:23:54","slug":"binocular-tour-17","status":"publish","type":"post","link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/2023\/01\/19\/binocular-tour-17\/","title":{"rendered":"Binocular tour"},"content":{"rendered":"\n

This month we\u2019re off to a dog show, finding the best in class in Canis Major<\/span><\/p>\n\n

With Steve Tonkin <\/span><\/p>\n\n

\"\"<\/figure>\n\n
1. M41 <\/strong><\/h5>\n\n

Recommended equipment: 10×50<\/strong><\/strong><\/strong><\/p>\n\n

This open cluster is bright enough for you to see it with your naked eye in a transparent sky. It is 4\u00b0 south of mag. \u20131.1 Sirius (Alpha (\u03b1) Canis Majoris) and is large enough to be an obvious cluster of stars in 10×50 binoculars. Using averted vision at a dark site, you should be able to resolve up to 10 of the brighter stars against the background glow of fainter members.<\/p>\n\n

2. M46\/47 <\/strong><\/h5>\n\n

Recommended equipment: 10×50<\/strong><\/strong><\/strong><\/p>\n\n

M46 and M47 offer contrasting examples of how open clusters can appear in small binoculars; you will find them 5\u00b0 south of mag. +3.9 Alpha (\u03b1) Monocerotis. The 1,600-lightyear-distant M47 is large and loose, but although M46 appears to be a similar size, it is actually much larger, richer and more compact. It is more than three times as distant at 5,500 lightyears and you probably won\u2019t be able to resolve any of its stars at all. <\/p>\n\n

3. M93 <\/strong><\/h5>\n\n

Recommended equipment: 15×70<\/strong><\/strong><\/strong><\/p>\n\n

If you place mag. +3.3 Azmidi (Xi (\u03be) Puppis) at the southeast of the field of view, M93 should appear near the centre of the field. M93 is a bright, rich, wedge-shaped cluster in which some 25\u201330 stars are visible in 15×70 binoculars, against a glowing backdrop of fainter stars. M93 is unusual in that, unlike most open clusters which are sparser at the periphery, it is the centre of this cluster that is sparse. <\/span><\/p>\n\n

4. The Omega CMa Group <\/strong><\/h5>\n\n

Recommended equipment: 10×50<\/strong><\/strong><\/strong><\/p>\n\n

Mag. +4.0 Omega (\u03c9) Canis Majoris <\/strong>lies 1.5\u00b0 east of mag. +1.8 Wezen (Delta (\u03b2) Canis Majoris). Note that it is a brilliant white compared to the fainter yellowish star just to the south. These two are part of a very pretty C-shaped string of stars of varying colour that extends from mag. +5.9 26 CMa in the north, through mag. +4.4 27 and Omega CMa, to a mag. +5.5 yellow star 1\u00b0 south of Wezen. <\/span><\/p>\n\n

5. UW Canis Majoris <\/strong><\/h5>\n\n

Recommended equipment: 10×50<\/strong><\/strong><\/strong><\/p>\n\n

Look 2.7\u00b0 northeast of Wezen for a pair of dazzlingly blue stars. The brighter one is mag. +4.4 Tau (\u03c4) Canis Majoris, but more interesting is the fainter mag. +4.8 UW Canis Majoris, less than 0.5\u00b0 north of Tau CMa. UW is a blue supergiant whose brightness falls by half a magnitude every 4.39 days as it is eclipsed by a fainter companion. <\/p>\n\n

6. The \u2018Winter Albireo\u2019 <\/strong><\/h5>\n\n

Recommended equipment: 15×70<\/strong><\/strong><\/strong><\/p>\n\n

Did you know that there is a winter equivalent of one of summer\u2019s popular double-star showpieces? The \u2018Winter Albireo\u2019 is HD 56577, 1.7\u00b0 north of Tau CMa. With a separation of 27 arcseconds, it is a bit tighter than its summer cousin, so use 15x70s to separate the mag. +4.8 orange and mag. +5.8 white components, contrasting beautifully with the blue of UW CMa in the same field of view. <\/p>\n\n

CHART: PETE LAWRENCE<\/p>\n","protected":false},"excerpt":{"rendered":"

This month we\u2019re off to a dog show, finding the best in class in Canis Major <\/p>\n","protected":false},"author":24,"featured_media":40240,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"ub_ctt_via":"","purple_page_number":"54","purple_custom_meta_purple_page_number":"54","purple_seq_number":"1","purple_custom_meta_purple_seq_number":"1","purple_source_article":"article_54-1.xml","purple_custom_meta_purple_source_article":"article_54-1.xml","purple_source_issue":"February-2023","purple_custom_meta_purple_source_issue":"February-2023","purple_external_id":"February-2023-54-1","purple_custom_meta_purple_external_id":"February-2023-54-1","purple_issue_code":"|0000086561||","purple_custom_meta_purple_issue_code":"|0000086561||","purple_android_product":"com.im.skyatnight.213","purple_custom_meta_purple_android_product":"com.im.skyatnight.213","purple_ios_product":"com.im.skyatnight.213","purple_custom_meta_purple_ios_product":"com.im.skyatnight.213","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\/2023\/01\/04958fce-173f-41c4-9a80-45b3e55bb5d0.jpg","author_info":{"display_name":"importmanagerhub@sprylab.com","author_link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/author\/importmanagerhubsprylab-com\/"},"acf":{"readingTimeMinutes":"3","apple_news_title":""},"uagb_featured_image_src":{"full":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2023\/01\/04958fce-173f-41c4-9a80-45b3e55bb5d0.jpg",2048,1183,false],"thumbnail":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2023\/01\/04958fce-173f-41c4-9a80-45b3e55bb5d0-150x150.jpg",150,150,true],"medium":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2023\/01\/04958fce-173f-41c4-9a80-45b3e55bb5d0-300x173.jpg",300,173,true],"medium_large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2023\/01\/04958fce-173f-41c4-9a80-45b3e55bb5d0-768x444.jpg",768,444,true],"large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2023\/01\/04958fce-173f-41c4-9a80-45b3e55bb5d0-1024x592.jpg",800,463,true],"1536x1536":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2023\/01\/04958fce-173f-41c4-9a80-45b3e55bb5d0-1536x887.jpg",1536,887,true],"2048x2048":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2023\/01\/04958fce-173f-41c4-9a80-45b3e55bb5d0.jpg",2048,1183,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":"This month we\u2019re off to a dog show, finding the best in class in Canis Major","_links":{"self":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/40241"}],"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=40241"}],"version-history":[{"count":5,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/40241\/revisions"}],"predecessor-version":[{"id":40929,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/40241\/revisions\/40929"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media\/40240"}],"wp:attachment":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media?parent=40241"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/categories?post=40241"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/tags?post=40241"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}