{"id":23415,"date":"2021-09-16T00:00:00","date_gmt":"2021-09-16T00:00:00","guid":{"rendered":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/?post_type=purple_issue&p=23415"},"modified":"2021-10-22T11:45:28","modified_gmt":"2021-10-22T11:45:28","slug":"deep-sky-tour","status":"publish","type":"post","link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/2021\/09\/16\/deep-sky-tour\/","title":{"rendered":"Deep-sky tour"},"content":{"rendered":"\n

Take in magnificent galaxies in the vicinity of Triangulum, the Triangle<\/p>\n\n

\"\"<\/figure><\/div>\n\n

1. M33<\/strong><\/h4>\n\n

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

M33 is a magnificent, albeit faint spiral galaxy in Triangulum. Although listed at mag. +5.7 it\u2019s hard to see. M33 is face-on to us and with an apparent size of 62 x 39 arcminutes, its surface brightness is low.<\/span> Locate it by extending the line from M31, the Andromeda Galaxy, through Mirach (Beta (b) Andromedae) for the same distance again.<\/span> A small scope under dark skies will show the central core as a misty fuzzball. A 250mm scope shows a mottled patchwork of dim light surrounding the core. <\/p>\n\n

2. Collinder 21 <\/strong><\/h4>\n\n

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

Our next target has a charm all its own. To locate it, start at Rasalmothallah (Alpha (a) Trianguli). Head 2.4\u02da south and 0.7\u02da west, where you\u2019ll find a mag. +8.1 star with a curve of 10th magnitude stars to its north. This is the cluster Collinder 21. The semi-circle has a diameter of 6 arcminutes. A small scope reveals six stars here, a 250mm instrument increasing the count to 14. <\/p>\n\n

3. NGC 627 (and IC 1727)<\/h4>\n\n

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

Heading 0.6\u02da northwest from the brightest star in Collinder 21 brings you to NGC 672, a spiral galaxy located 23.4 million lightyears away. A 150mm scope reveals the object to be elongated, with a hint of brightness at its centre. With a visual magnitude of +10.8 and a size 6.6 x 2.7 arcminutes, like M33, NGC 672 suffers from low surface brightness. This is an interacting galaxy, deformed by gravitational forces inflicted by IC 1727, a mag. +12.1 irregular galaxy located 6 arcminutes to the west. A 250mm instrument reveals NGC 672 to be 4 arcminutes long and 1.5 arcminutes wide. <\/span><\/p>\n\n

\"\"
View the Triangulum Galaxy, M33, through a 250mm telescope to reveal the mottled patchwork of the spiral galaxy <\/figcaption><\/figure><\/div>\n\n

4. NGC 777<\/strong><\/h4>\n\n

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

We head inside the pointed isosceles triangle that is Triangulum for our next target, the 12th magnitude elliptical galaxy NGC 777. It\u2019s visible in a 150mm instrument, despite its dim magnitude, but again dark skies are recommended. To locate it, imagine the middle line of the Triangulum triangle starting at Rasalmothallah. Head 2.4\u02da along this line from Rasalmothallah where<\/span> you\u2019ll find a mag. +8.7 star with a mag. +9.3 star 6.5 arcminutes to the west: TYC2308-878-1 and TYC2308-585-1 respectively. NGC 777 forms a right-angled triangle with these stars, TYC2308-585-1 at the right angle. The galaxy lies 4.7 arcminutes from TYC2308-<\/span> 585-1 in a direction away from Rasalmothallah. It\u2019s dim in a 150mm instrument, a misty patch with a star-like nucleus; and is 1 arcminute across in a 250mm scope. <\/p>\n\n

5. NGC 784<\/strong><\/h4>\n\n

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

For our penultimate target, the virtually edge-on barred spiral galaxy NGC 784, head 2.3\u02da southeast of Rasalmothallah to locate mag. +6.6 HIP 9493. You\u2019ll find NGC 784 28 arcminutes to the north of this star. Again, this galaxy is listed at a reasonably bright mag. +11.8 but suffers from low surface brightness. A 150mm scope will show it as a faint scratch of light orientated north-south. A large scope is necessary to do it justice, the galaxy appearing 6 arcminutes long and nearly an arcminute wide through a 300mm instrument. The mistiness of the galaxy\u2019s elongated halo surrounds a brighter inner region roughly 1.5 arcminutes in length. Through larger instruments, there\u2019s a definite mottled texture across the galaxy\u2019s length. <\/p>\n\n

6. NGC 890<\/strong><\/h4>\n\n

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

Our final target is NGC 890, an 11th magnitude lenticular galaxy sitting 1.1\u02da east-southeast of Gamma (g) Trianguli in a barren area of sky. The best strategy to locate it is to use the short edge of Triangulum formed by drawing a line from Beta (b) through Gamma Trianguli. Keep this line going for about half the distance again and you\u2019ll be in the right area. Listed with an integrated magnitude of +11.1, a 150mm instrument sees it as a slightly elongated glow. A 250mm scope reveals an object approaching 2 arcminutes in length and 1 arcminute wide under dark-sky conditions. <\/p>\n\n

\n\n

This Deep-Sky Tour has been automated<\/strong><\/p>\n\n

ASCOM-enabled Go-To mounts can now take you to this month\u2019s targets at the touch of a button, with our Deep-Sky Tour file for the EQTOUR app. Find it online.<\/p>\n\n

<\/div>
\n

More ONLINE <\/strong><\/h4>\n\n\n\n

Print out this chart and take an automated Go-To tour. See page 5 for instructions.<\/strong><\/p>\n<\/div><\/section>\n\n

Photos: CHRISTOPH KALTSEIS\/CCDGUIDE.COM, CHART BY PETE LAWRENCE<\/p>\n","protected":false},"excerpt":{"rendered":"

Take in galaxies in the vicinity of Triangulum, the Triangle<\/p>\n","protected":false},"author":24,"featured_media":24838,"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":"October-2021","purple_custom_meta_purple_source_issue":"October-2021","purple_external_id":"October-2021-56-1","purple_custom_meta_purple_external_id":"October-2021-56-1","purple_issue_code":"|0000086545||","purple_custom_meta_purple_issue_code":"|0000086545||","purple_android_product":"com.im.skyatnight.197","purple_custom_meta_purple_android_product":"com.im.skyatnight.197","purple_ios_product":"com.im.skyatnight.197","purple_custom_meta_purple_ios_product":"com.im.skyatnight.197","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\/09\/H9F87U8EKLYVMNY1OI85BG709P7B.jpg","author_info":{"display_name":"importmanagerhub@sprylab.com","author_link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/author\/importmanagerhubsprylab-com\/"},"acf":{"readingTimeMinutes":"4"},"uagb_featured_image_src":{"full":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2021\/09\/H9F87U8EKLYVMNY1OI85BG709P7B.jpg",1192,1192,false],"thumbnail":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2021\/09\/H9F87U8EKLYVMNY1OI85BG709P7B-150x150.jpg",150,150,true],"medium":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2021\/09\/H9F87U8EKLYVMNY1OI85BG709P7B-300x300.jpg",300,300,true],"medium_large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2021\/09\/H9F87U8EKLYVMNY1OI85BG709P7B-768x768.jpg",768,768,true],"large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2021\/09\/H9F87U8EKLYVMNY1OI85BG709P7B-1024x1024.jpg",800,800,true],"1536x1536":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2021\/09\/H9F87U8EKLYVMNY1OI85BG709P7B.jpg",1192,1192,false],"2048x2048":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2021\/09\/H9F87U8EKLYVMNY1OI85BG709P7B.jpg",1192,1192,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":"Take in galaxies in the vicinity of Triangulum, the Triangle","_links":{"self":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/23415"}],"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=23415"}],"version-history":[{"count":5,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/23415\/revisions"}],"predecessor-version":[{"id":24962,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/23415\/revisions\/24962"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media\/24838"}],"wp:attachment":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media?parent=23415"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/categories?post=23415"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/tags?post=23415"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}