{"id":31963,"date":"2022-05-24T10:20:24","date_gmt":"2022-05-24T10:20:24","guid":{"rendered":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/?post_type=purple_issue&p=31963"},"modified":"2022-05-24T10:20:24","modified_gmt":"2022-05-24T10:20:24","slug":"deep-sky-tour-9","status":"publish","type":"post","link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/2022\/05\/24\/deep-sky-tour-9\/","title":{"rendered":"Deep-sky tour"},"content":{"rendered":"\n

This month we take in sights in the constellation of Ophiuchus, the Serpent Bearer<\/p>\n\n

\"\"
The inset of Target 4 represents an inverted view through an eyepiece<\/figcaption><\/figure>\n\n
1. IC 4665<\/strong><\/h5>\n\n

Recommended equipment: Small\/medium telescope<\/strong><\/p>\n\n

Ophiuchus is a large ill-defined patch of the early summer sky. Its main form appears as a box with a \u2018roof\u2019, the apex marked by Rasalgethi (Alpha (\u03b1) Ophiuchui) representing Ophiuchus\u2019s head. The eastern vertex of the roof connects with the box at (Cebalrai (Beta (\u03b2) Ophiuchi) and you\u2019ll find our first tour target, the large open cluster IC 4665, 1.3\u02da to the north of this star.<\/span> IC 4665 is a young and close cluster, estimated to be 40 million years old and only 1,400 lightyears away. Best viewed with a low-power eyepiece, it appears 45 arcminutes across. <\/span><\/p>\n\n

2. NGC 6426<\/strong><\/h5>\n\n

Recommended equipment: Large telescope<\/strong><\/p>\n\n

Our next target lies 1.6\u02da to the south of mag. +2.8 Cebalrai. Here you\u2019ll find the mag. +11.1 globular cluster NGC 6426. It\u2019s more difficult to see as it\u2019s fairly dim and quite small with a diameter of 3 arcminutes. A 250mm scope shows it as little more than a faint smudge, barely 2.5 arcminutes across. With averted vision and high magnification it should be possible to see that the smudge is brightening towards the centre. Increasing the aperture to 300mm will show little more than this to be honest, the faint, centre-bright patch being easier to see, but not showing any stellar granularity. This globular is located at a distance of 67,200 lightyears. <\/span><\/p>\n\n

3. Collinder 350<\/strong><\/h5>\n\n

Recommended equipment: Small\/medium telescope<\/strong><\/p>\n\n

Our next target is open cluster Collinder 350. To locate it, head 2\u02da south of Cebalrai to mag. +6.2 HIP 86831. Head 0.8\u02da east for mag. +3.9 Gamma (\u03b3) Ophiuchi and 0.8\u02da south-southeast to mag. +6.4<\/span> HIP 87224. This orange star is the north vertice of a right-angled triangle with mag. +7.5 HIP 87244 and mag. +6.6 HIP 86969, both also orange. Collinder 350 sits between HIP 87224 and HIP 86969. At mag. +6.1, this is a tricky object because it\u2019s large, sparse and sits on the Milky Way\u2019s edge. As was the<\/span> situation with IC 4665, Collinder 350 requires a low power for the best view. Go too high and you\u2019ll be looking at stars within it, but not realising that they are part of a cluster! In total, there are 15 stars to be see. <\/span><\/p>\n\n

\"\"
The globular cluster M14 was discovered in 1764 by Charles Messier<\/figcaption><\/figure><\/div>\n\n
4. Barnard\u2019s Star<\/strong><\/h5>\n\n

Recommended equipment: Small\/medium or large telescope<\/strong><\/p>\n\n

Our next stop is unusual in that\u2019s its just a star. Located 3.5\u02da east of Cebalrai and 0.7\u02da west-northwest of mag. +4.8 66 Ophiuchi, is mag. +9.5 HIP 87937. This is Barnard\u2019s Star, named after its discoverer EE Barnard, who identified it in 1916. It\u2019s a neighbour of the Sun at a distance of<\/span> 6 lightyears. It shows the largest \u2018proper motion\u2019 of any of the night-time stars. This term describes the apparent movement of a star against the stellar background. In the case of Barnard\u2019s Star it\u2019s 10.4 arcseconds per year. <\/p>\n\n

5. M14 <\/strong><\/h5>\n\n

Recommended equipment: Small\/medium or large telescope<\/strong><\/p>\n\n

Head 7.5\u02da south of Cebalrai and nudge 2\u02da west to find our next target, globular cluster M14. Shining with an integrated magnitude of +7.6, this Messier-listed globular appears large through the eyepiece of a 150mm scope. Using a high power with a 150mm scope just starts to reveal some granularity in the globular\u2019s texture. Larger apertures will show that the globular is slightly elongated in a northeast-southwest orientation. Above 250mm a few resolved stars may be seen, but even a 300mm struggles to show much more than just a few stars spread over an area 9 arcminutes across. <\/p>\n\n

6. NGC 6366<\/strong><\/h5>\n\n

Recommended equipment: Small\/medium or large telescope<\/strong><\/p>\n\n

Globular cluster NGC 6366 is easy to locate as it sits 16 arcminutes to the east of mag. +4.5 HIP 85365. This globular responds favourably to aperture, although at the lower end you probably won\u2019t see a great deal more than a featureless glow with no central condensation nor any resolved stars. A pair of tenth magnitude stars sit on the HIP 85365 side of the globular and there\u2019s a closer pair of 12th magnitude stars on its southern side. By using an aperture of 250mm, it\u2019s possible to see a few resolved stars scattered over a 4-arcminute area. A 300mm aperture increases the number of faint stars as well as extending the area over which they are seen to around 8 arcminutes.<\/p>\n\n

MICHAEL BREITE\/ STEFAN HEUTZ\/ WOLFGANG RIES\/CCDGUIDE.COM, CHART BY PETE LAWRENCE<\/p>\n","protected":false},"excerpt":{"rendered":"

This month we take in sights in the constellation of Ophiuchus, the Serpent Bearer<\/p>\n","protected":false},"author":24,"featured_media":31962,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"ub_ctt_via":"","purple_page_number":"56","purple_custom_meta_purple_page_number":"56","purple_seq_number":"1","purple_custom_meta_purple_seq_number":"1","purple_source_article":"article_56-1.xml","purple_custom_meta_purple_source_article":"article_56-1.xml","purple_source_issue":"June-2022","purple_custom_meta_purple_source_issue":"June-2022","purple_external_id":"June-2022-56-1","purple_custom_meta_purple_external_id":"June-2022-56-1","purple_issue_code":"|0000086553||","purple_custom_meta_purple_issue_code":"|0000086553||","purple_android_product":"com.im.skyatnight.205","purple_custom_meta_purple_android_product":"com.im.skyatnight.205","purple_ios_product":"com.im.skyatnight.205","purple_custom_meta_purple_ios_product":"com.im.skyatnight.205","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\/2022\/05\/cc3917da-d60c-4745-937c-ba6778b8dd38.jpg","author_info":{"display_name":"importmanagerhub@sprylab.com","author_link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/author\/importmanagerhubsprylab-com\/"},"acf":{"readingTimeMinutes":"4","apple_news_title":""},"uagb_featured_image_src":{"full":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/05\/cc3917da-d60c-4745-937c-ba6778b8dd38.jpg",1482,2048,false],"thumbnail":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/05\/cc3917da-d60c-4745-937c-ba6778b8dd38-150x150.jpg",150,150,true],"medium":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/05\/cc3917da-d60c-4745-937c-ba6778b8dd38-217x300.jpg",217,300,true],"medium_large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/05\/cc3917da-d60c-4745-937c-ba6778b8dd38-768x1061.jpg",768,1061,true],"large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/05\/cc3917da-d60c-4745-937c-ba6778b8dd38-741x1024.jpg",741,1024,true],"1536x1536":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/05\/cc3917da-d60c-4745-937c-ba6778b8dd38-1112x1536.jpg",1112,1536,true],"2048x2048":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/05\/cc3917da-d60c-4745-937c-ba6778b8dd38.jpg",1482,2048,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 take in sights in the constellation of Ophiuchus, the Serpent Bearer","_links":{"self":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/31963"}],"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=31963"}],"version-history":[{"count":4,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/31963\/revisions"}],"predecessor-version":[{"id":32477,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/31963\/revisions\/32477"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media\/31962"}],"wp:attachment":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media?parent=31963"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/categories?post=31963"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/tags?post=31963"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}