{"id":32835,"date":"2022-06-16T00:00:00","date_gmt":"2022-06-16T00:00:00","guid":{"rendered":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/?post_type=purple_issue&p=32835"},"modified":"2022-07-12T14:59:06","modified_gmt":"2022-07-12T14:59:06","slug":"deep-sky-tour-10","status":"publish","type":"post","link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/2022\/06\/16\/deep-sky-tour-10\/","title":{"rendered":"Deep-sky tour"},"content":{"rendered":"\n

This month we take in sights in the middle of the constellation of Aquila, the Eagle <\/p>\n\n

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

1 NGC 6790 <\/strong><\/h4>\n\n

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

Aquila, the Eagle, is marked by mag. +3.3 Delta (\u03b4) Aquilae, which is a good place to start our tour. The planetary nebula NGC 6790 is located 1.6\u02da south and 0.6\u02da west of mag. +3.3 Delta (\u03b4) Aquilae. It\u2019s tiny, with an apparent size of 4 x3 arcseconds, which is similar to the apparent size of Uranus. At this size, the 19,000 lightyeardistant planetary won\u2019t show much detail, even through large scopes, but smaller planetaries tend to have a higher surface brightness. NGC 6790 is listed with an integrated magnitude of +10.5. Although in most amateur scopes it appears as little more than a blue\/green fuzzy star, a visual OIII (Oxygen) filter will cause the surrounding field stars to dim while the planetary remains bright, an important planetary-hunting technique.<\/span><\/p>\n\n

2 NGC 6760 <\/strong><\/h4>\n\n

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

Imagine Delta (\u03b4) Aquilae as the 12 o\u2019clock position on a clock face. Using NGC 6790 as the dim centre of the clock, at the 4 o\u2019clock position lies mag. +5.1 HIP 94885. Our next tour target, globular cluster NGC 6760, lies 1.8\u02da west of this star. Unlike NGC 6790, NGC 6760 has a good size to it, visually appearing around 6 arcminutes across through larger instruments. Its integrated magnitude is listed as mag. +9.1, so it\u2019s easy to find with smaller instruments too. The apparent size of deep-sky objects varies with the aperture of the scope they\u2019re being observed with. A 150mm telescope shows NGC 6760 as a two-arcminute object with a mottled texture at 150x magnification. A 250mm scope shows it larger, nearing four arcminutes across and with a well-defined core. <\/p>\n\n

3 NGC 6755 <\/strong><\/h4>\n\n

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

Head 3.2\u02da north-northwest of NGC 6760 and you\u2019ll be in the vicinity of our next target, open cluster NGC 6755. This is unusual because it appears to be divided by a dark region running from the northeast through to the southwest. This splits the cluster stars into two unequally bright regions, the southeastern one appearing brighter than the northwestern one. NGC<\/span> 6755 is located within the Milky Way\u2019s boundary, but despite the multitude of background stars here, it still manages to stand out well. Shining with an integrated magnitude of +7.5, the cluster covers an area roughly half the apparent size of the Moon.<\/p>\n\n

4 NGC 6756 <\/strong><\/h4>\n\n

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

NGC 6756 is another open cluster, located half a degree to the north of NGC 6755. It\u2019s fainter than NGC 6755, listed at 11th magnitude. It also appears smaller, about 4 arcminutes across through larger scopes. A 150mm scope shows it as a 3-arcminute diameter faintly glowing patch. At 150x power, almost a dozen resolved stars can be seen. It appears as two halves due to the uneven distribution of brighter stars. <\/p>\n\n

\"\"
Use a 250mm telescope to reveal an off-centre dark patch in the planetary nebula NGC 6781 <\/figcaption><\/figure><\/div>\n\n

5 NGC 6781 <\/strong><\/h4>\n\n

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

Planetary nebula NGC 6781 lies 3\u02da northeast of NGC 6756. Unlike our first target, NGC 6781 has an appreciable apparent size of 1.7 arcminutes, although shining with an integrated magnitude of +11.4, its surface brightness is reduced. Despite this, a 150mm scope shows its large circular glow easily. Use a magnification over 100x for the best view. A 250mm instrument reveals asymmetry in the disc brightness, the region to the south being brightest. A dark patch which appears off-centre may also be seen, displaced to the north.<\/span><\/p>\n\n

6 NGC 6803 <\/strong><\/h4>\n\n

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

NGC 6803 is a challenging target, 4.7\u02da to the northeast of NGC 6781, and 4\u02da and a fraction south of Tarazed (Gamma (\u03b3) Aquilae). Listed at mag. +11.4, it\u2019s tiny at 5 arcseconds, and a little larger than the apparent size of Mars when furthest from Earth. The nebula\u2019s tiny apparent diameter makes it hard to discern from the surrounding stars. A mag. +13.2 star sits to the north-northwest of NGC 6803\u2019s tiny disc, which also helps to disguise the object. Here, the OIII blink technique mentioned for Item 1 works well.<\/span> Select a mid\u2013 to high power eyepiece and move the filter between your eye and the ocular. If the OIII filter dims everything too much, try a UHC filter.<\/p>\n\n

<\/p>\n\n

Photos: 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 middle of the constellation of Aquila, the Eagle <\/p>\n","protected":false},"author":24,"featured_media":32832,"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":"July-2022","purple_custom_meta_purple_source_issue":"July-2022","purple_external_id":"July-2022-56-1","purple_custom_meta_purple_external_id":"July-2022-56-1","purple_issue_code":"|0000086554||","purple_custom_meta_purple_issue_code":"|0000086554||","purple_android_product":"com.im.skyatnight.206","purple_custom_meta_purple_android_product":"2022skyatnightJuly","purple_ios_product":"com.im.skyatnight.206","purple_custom_meta_purple_ios_product":"2022skyatnightJuly","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\/06\/5869bb93-72d7-40e9-bc03-f9cc8d833c0e.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\/06\/5869bb93-72d7-40e9-bc03-f9cc8d833c0e.jpg",1005,1004,false],"thumbnail":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/06\/5869bb93-72d7-40e9-bc03-f9cc8d833c0e-150x150.jpg",150,150,true],"medium":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/06\/5869bb93-72d7-40e9-bc03-f9cc8d833c0e-300x300.jpg",300,300,true],"medium_large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/06\/5869bb93-72d7-40e9-bc03-f9cc8d833c0e-768x767.jpg",768,767,true],"large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/06\/5869bb93-72d7-40e9-bc03-f9cc8d833c0e.jpg",800,799,false],"1536x1536":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/06\/5869bb93-72d7-40e9-bc03-f9cc8d833c0e.jpg",1005,1004,false],"2048x2048":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/06\/5869bb93-72d7-40e9-bc03-f9cc8d833c0e.jpg",1005,1004,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 middle of the constellation of Aquila, the Eagle","_links":{"self":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/32835"}],"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=32835"}],"version-history":[{"count":5,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/32835\/revisions"}],"predecessor-version":[{"id":33162,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/32835\/revisions\/33162"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media\/32832"}],"wp:attachment":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media?parent=32835"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/categories?post=32835"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/tags?post=32835"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}