{"id":33604,"date":"2022-07-20T00:00:00","date_gmt":"2022-07-20T00:00:00","guid":{"rendered":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/?post_type=purple_issue&p=33604"},"modified":"2022-07-21T14:22:00","modified_gmt":"2022-07-21T14:22:00","slug":"a-parade-of-planetary-nebulae","status":"publish","type":"post","link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/2022\/07\/20\/a-parade-of-planetary-nebulae\/","title":{"rendered":"A parade of planetary nebulae"},"content":{"rendered":"\n

Stuart Atkinson <\/strong>seeks out six of the loveliest examples of these deep-sky objects for you to track down in the late-summer skies<\/p>\n\n

Stuart Atkinson<\/span><\/p>\n\n

\"\"
Showstopper M27, the Dumbbell Nebula, one of the beautiful targets for your planetary nebulae hunt <\/figcaption><\/figure>\n\n

One of the most fascinating facts I ever learned about astronomy is that stars don\u2019t last forever: like us, they are born, live a life and eventually die. Okay, so those lives are rather longer than ours, but every single star in the sky is on borrowed time. <\/p>\n\n

Thanks to science fiction, a common misconception is that all stars die in cataclysmic explosions, like the Death Star. <\/p>\n\n

The largest do, becoming supernovae that can briefly outshine a whole galaxy, while the smallest ones just shrink and fade away, like forgotten pop stars. In between, the quieter, less attention-seeking stars the size of our own Sun \u2013 that is, with diameters of a million kilometres or so \u2013 die like celestial souffles, swelling up and then shrinking again; but not before they pop, puff off their outer layers like colourful smoke rings and surround themselves with beautiful shells of gas and dust. Because through the eyepiece these shells have a resemblance to planets, they are known as \u2018planetary nebulae\u2019. <\/p>\n\n

Planetary nebulae are important scientifically because they allow us to study the evolutionary processes of stars similar to our own Sun, and see into its future. By studying them at different wavelengths, we can explore the amount and composition of the dust and gas inside their shells, allowing us to understand better what stars are made of. It\u2019s even possible to watch the material inside a planetary nebula\u2019s shells expanding, by taking multiple images over long periods of time and comparing them. We won\u2019t be around to see what happens to the Sun as it nears the end of its life, but studying planetary nebulae allows us to jump in a TARDIS and travel into the future to do just that. <\/p>\n\n

Keep it dark <\/strong><\/h4>\n\n

These fascinating objects are also simply beautiful to look at, and now is a great time to observe them because a wide variety are scattered across the sky, many in constellations around the frothy borders of the Milky Way, which is famously best seen at this time of year. <\/p>\n\n

The trick is to wait until the sky is as dark as possible \u2013 no Moon, no light pollution \u2013 and then, after finding the nebula in a widefield eyepiece, use your favourite highmagnification eyepiece to really zoom in. <\/p>\n\n

You\u2019ll see the striking contrast between the nebula and the sky around it, unusual shapes, ghostly smoke rings and delicate puffballs. If the seeing is very good and your equipment is behaving, you might even see the star at the centre, like a tiny pollen grain surrounded by the shells of glowing gas and dust. <\/p>\n\n

Although the sky never gets truly dark during the next couple of months, it still gets dark enough to find the planetary nebulae on our list. So whether you own a Dobsonian \u2018ship\u2019s cannon\u2019, a small refractor or even just a pair of binoculars, there will be something here for you to see. > <\/p>\n\n

\"\"<\/figure>\n\n
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Larger instruments and good seeing reveal the Saturn Nebula\u2019s subtle colours <\/figcaption><\/figure>\n\n

1. The Saturn Nebula <\/strong><\/h4>\n\n

Catalogue number: <\/strong>NGC 7009 <\/p>\n\n

Constellation: <\/strong>Aquarius<\/p>\n\n

Magnitude: <\/strong>+7.8 <\/p>\n\n

Equipment: <\/strong>6-inch scope <\/p>\n\n

There are no prizes for guessing how this nebula earned its nickname. With its bright core and small \u2018wings\u2019 on either side, it really does resemble a smoky, slightly blurry Saturn through the eyepiece of a telescope under high magnification. This was how it looked to the Earl of Rosse who gave it the name after observing it with his giant Leviathan of Parsonstown telescope around 1840, and possibly to William Herschel when he first discovered it in 1782. <\/p>\n\n

The Saturn Nebula lies around 2,900 lightyears away from Earth and you should be able to find it fairly easily, just under a degree and a half west of mag. +4.5 star Nu (\u03bd) Aquarii. You will need really high magnification, good seeing and a dark sky to pick up its faint blue-white colour. Coincidentally, during August the real planet Saturn will be shining fairly close by, below and to the east of the Saturn Nebula, so you should be able to directly compare the two through your telescope. <\/p>\n\n

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You can spot this big, bright favourite even with a pair of binoculars <\/figcaption><\/figure>\n\n

2. The Dumbbell Nebula <\/strong><\/h4>\n\n

Catalogue number: <\/strong>M27 <\/p>\n\n

Constellation: <\/strong>Vulpecula<\/p>\n\n

Magnitude: <\/strong>+7.1 <\/p>\n\n

Equipment: <\/strong>3-inch scope <\/p>\n\n

A ghostly disc with a bite taken out of each side, the Dumbbell Nebula is one of the most recognised planetary nebulae in the sky. It is large and bright enough to see with a small telescope and even looking through binoculars \u2013 if you know exactly where to look. It is easy to lose sight of it amid all the peppercorn stars of the Milky Way, close to the celestial crowds of the Cygnus Star Cloud. <\/p>\n\n

At low powers the Dumbbell Nebula is more oval than dumbbell-shaped, looking like a tiny, misty rugby ball. You will need to crank the magnification up to observe the twin lobes, or fans, that give it its name. That will also help your eye to detect the subtle green hue of the nebula, but only if your eyesight is dark-adapted under a dark sky. You will find M27 near to the sharp tip of the starry arrow constellation, Sagitta, and just 23 arcminutes beneath the mag. +5.7 star 14 Vulpeculae. <\/p>\n\n

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The giant eye of the Helix Nebula is \u2013 ironically \u2013 tricky to see due to its low surface brightness <\/figcaption><\/figure>\n\n

3. The Helix Nebula <\/strong><\/h4>\n\n

Catalogue number: <\/strong>NGC 7293 <\/p>\n\n

Constellation: <\/strong>Aquarius <\/p>\n\n

Magnitude: <\/strong>+7.6 <\/p>\n\n

Equipment: <\/strong>6-inch scope <\/p>\n\n

The Helix Nebula is perhaps the closest planetary nebula to our Solar System, around 650 lightyears away, and is approximately 2.5 lightyears across. It is a much-loved object among deep-sky astrophotographers because of its complicated structure and size, but visual observers find it rather challenging and often frustrating. You can seek it out about a third of the way between Upsilon (\u03c5) Aquarii and 47 Aquarii. Visually it is a large object, around half the size of the full Moon, but being so big means its faint light is spread over a wide area, giving it a low surface brightness that presents a challenge for small scopes and binoculars. Larger scopes fitted with low-power eyepieces show it as a pale, hazy disc.<\/span> Only under really good conditions will a telescope be able to show any of its multiple pale arcs and crescents of smoky light.<\/p>\n\n

\"\"
With serious magnification M57 turns from a smudge to spectacular <\/figcaption><\/figure>\n\n

4. The Ring Nebula <\/strong><\/h4>\n\n

Catalogue number: <\/strong>M57 <\/p>\n\n

Constellation: <\/strong>Lyra <\/p>\n\n

Magnitude: <\/strong>+8.8 <\/p>\n\n

Equipment: <\/strong>6-inch scope <\/p>\n\n

M57 is arguably the most famous planetary nebula in the sky because it actually looks like the thing it\u2019s named after, a ring \u2013 although only through a telescope. Through binoculars you can just make out M57 as a blue-green dot looking almost like an out-of-focus star, halfway between the 3rd-magnitude stars Sulafat (Gamma (\u03b3) Lyrae) and Sheliak (Beta (\u03b2) Lyrae), down at the base of Lyra, the Lyre. <\/p>\n\n

A small telescope reveals tantalising hints of its ring structure (using averted vision helps), but point a medium to large telescope at it and the ring will jump out at you, as will its slightly oval shape. If you really pump up the magnification you\u2019ll be able to see the 12th-magnitude parent star in the centre of the ring. Be aware that while M57 has a distinctive red colour on long exposure photos, your eye will only see it as a misty grey-green.<\/span><\/p>\n\n

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Use averted vision to catch a glimpse of the Owl\u2019s central dying star <\/figcaption><\/figure>\n\n

5. The Owl Nebula <\/strong><\/h4>\n\n

Catalogue number: <\/strong>M97 <\/p>\n\n

Constellation: <\/strong>Ursa Major <\/p>\n\n

Magnitude: <\/strong>+9.8 <\/p>\n\n

Equipment: <\/strong>8-inch scope <\/p>\n\n

Despite its low brightness, M97 is a popular target for deep-sky observers and photographers alike. It\u2019s one of the easiest planetary nebulae to find because it lies just below the universally familiar Big Dipper or Plough asterism, on the right side of the bottom of its bowl, just over 2\u00ba \u2013 or four Moon widths \u2013 away from the lower of the Big Dipper\u2019s pointer stars, Merak (Beta (\u03b2) Ursae Majoris). <\/p>\n\n

It\u2019s also a favourite because of its striking appearance through a telescope. While with smaller scopes and binoculars you will see a dimly glowing disc, a large instrument and high magnification will reveal more of its structure: a round, pale, smoky blue-green ball with two dark areas inside it that really do give it the appearance of an owl\u2019s face, with two blinking eyes. At 16th magnitude, the central star is very faint but might pop in and out of view if you use averted vision. M97 is estimated to be around 2,030 lightyears away and two lightyears wide. <\/p>\n\n

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Look for the bright Blue Snowball\u2019s distinctive blue tinge and elongated shape <\/figcaption><\/figure><\/div>\n\n

6. The Blue Snowball Nebula <\/strong><\/h4>\n\n

Catalogue number: <\/strong>NGC 7662 <\/p>\n\n

Constellation: <\/strong>Andromeda<\/p>\n\n

Magnitude: <\/strong>+8.3 <\/p>\n\n

Equipment: <\/strong>6-inch scope <\/p>\n\n

A less well-known target to seek out this summer is the Blue Snowball Nebula, although NGC 7662 is close enough to the north celestial pole that it is visible from the UK on almost every night of the year. You\u2019ll find it in a relatively barren area of sky between the Great Square of Pegasus and the W of Cassiopeia. As its name suggests, it is a round, fuzzy object that shines with a pale blue colour that is hinted at in small telescopes but more obvious in larger instruments. <\/p>\n\n

Under high magnification, on a dark night and with good seeing, you\u2019ll be able to spot subtle variations of shade and colour, and you may even be lucky enough to catch sight of its very faint central star. Recent studies suggest it lies 5,600 lightyears away and has a diameter of just under a lightyear. Look for it between the stars Iota (\u03b9) Andromedae and Omicron (\u03bf) Andromedae. <\/p>\n\n

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

Stuart Atkinson is a lifelong amateur astronomer and author of 11 books on astronomy and spaceflight<\/p>\n\n

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

Six lovely deep-sky objects to track down in the late-summer skies<\/p>\n","protected":false},"author":24,"featured_media":33595,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"ub_ctt_via":"","purple_page_number":"28","purple_custom_meta_purple_page_number":"28","purple_seq_number":"1","purple_custom_meta_purple_seq_number":"1","purple_source_article":"article_28-1.xml","purple_custom_meta_purple_source_article":"article_28-1.xml","purple_source_issue":"August-2022","purple_custom_meta_purple_source_issue":"August-2022","purple_external_id":"August-2022-28-1","purple_custom_meta_purple_external_id":"August-2022-28-1","purple_issue_code":"|0000086555||","purple_custom_meta_purple_issue_code":"|0000086555||","purple_android_product":"com.im.skyatnight.207","purple_custom_meta_purple_android_product":"com.im.skyatnight.207","purple_ios_product":"com.im.skyatnight.207","purple_custom_meta_purple_ios_product":"com.im.skyatnight.207","purple_web_product":"","purple_custom_meta_purple_web_product":"","purple_publication_id":"075fab74-0a21-4201-866a-899d6c41c40c","purple_migrated":"","kt_blocks_editor_width":""},"categories":[21],"tags":[14],"featured_image_src":"https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/07\/ec2e5027-ffa6-4cf6-afd9-e7d0fdaa212a.jpg","author_info":{"display_name":"importmanagerhub@sprylab.com","author_link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/author\/importmanagerhubsprylab-com\/"},"acf":{"readingTimeMinutes":"9","apple_news_title":""},"uagb_featured_image_src":{"full":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/07\/ec2e5027-ffa6-4cf6-afd9-e7d0fdaa212a.jpg",1448,2048,false],"thumbnail":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/07\/ec2e5027-ffa6-4cf6-afd9-e7d0fdaa212a-150x150.jpg",150,150,true],"medium":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/07\/ec2e5027-ffa6-4cf6-afd9-e7d0fdaa212a-212x300.jpg",212,300,true],"medium_large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/07\/ec2e5027-ffa6-4cf6-afd9-e7d0fdaa212a-768x1086.jpg",768,1086,true],"large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/07\/ec2e5027-ffa6-4cf6-afd9-e7d0fdaa212a-724x1024.jpg",724,1024,true],"1536x1536":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/07\/ec2e5027-ffa6-4cf6-afd9-e7d0fdaa212a-1086x1536.jpg",1086,1536,true],"2048x2048":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/07\/ec2e5027-ffa6-4cf6-afd9-e7d0fdaa212a.jpg",1448,2048,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":"Six lovely deep-sky objects to track down in the late-summer skies","_links":{"self":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/33604"}],"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=33604"}],"version-history":[{"count":10,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/33604\/revisions"}],"predecessor-version":[{"id":34299,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/33604\/revisions\/34299"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media\/33595"}],"wp:attachment":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media?parent=33604"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/categories?post=33604"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/tags?post=33604"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}