{"id":25002,"date":"2021-10-05T08:12:21","date_gmt":"2021-10-05T08:12:21","guid":{"rendered":"https:\/\/www.skyatnightmagazine.com\/?p=100550"},"modified":"2021-10-05T08:26:08","modified_gmt":"2021-10-05T08:26:08","slug":"a-guide-to-the-triangulum-constellation","status":"publish","type":"rss_feed","link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/rss_feed\/a-guide-to-the-triangulum-constellation\/","title":{"rendered":"A guide to the Triangulum constellation"},"content":{"rendered":"

<\/p>

By Anton Vamplew\n \t\t<\/p>

Published: Tuesday, 05 October 2021 at 12:00 am<\/p>

\n\n

Some constellations are big, bold and easily recognisable \u2013 like Orion, the Hunter \u2013 and these take pride of place for stargazers.<\/p>\n

Other, smaller patterns get forgotten. One such constellation is Triangulum, the Triangle. It\u2019s no surprise to discover that Triangulum is made of three stars.<\/p>\n

And while they\u2019re by no means the brightest stars in the sky, the constellation they make has a very long history. Triangulum was known at the time of the ancient Greeks over 2,000 years ago.<\/p>\n

The name of their chief god, Zeus, begins with the letter delta (\u2206) and this could well be the idea behind the formation of this constellation.<\/p>\n

It clearly made the same shape, if a little squashed, in the sky.<\/p>\n

How to find the Triangulum constellation<\/strong><\/h1>\n
\""A\"<\/div>
Use the Great Square of Pegasus or the Andromeda Galaxy to help you find the Triangulum constellation and galaxy M33.<\/span><\/figcaption><\/div>\n

The Triangulum constellation \u2013 and the famous Triangulum Galaxy<\/a> (M33) that resides within the constellation \u2013 are relatively easy to find because they are surrounded by other famous constellations, asterisms<\/a> and deep-sky objects.<\/p>\n

One way of finding the Triangulum Galaxy would be to use the Great Square of Pegasus<\/a> as a starting-off point to star-hop<\/a> to the Andromeda Galaxy<\/a>.<\/p>\n

You can then use stars Mirach and Hamal to hop to the galaxy.\u00a0From there, the Triangulum constellation itself should be easy to spot.<\/p>\n

Once you\u2019ve found Triangulum, get your telescope out and see if you can spot some other deep-sky targets in the region.<\/p>\n

6 deep-sky targets to observe in Triangulum<\/strong><\/h1>\n

Get to know the Triangulum constellation better with our deep-sky tour, taking in 6 beautiful objects to observe through a telescope. Download a PDF chart<\/a> to help you locate the objects.
<\/p>

1<\/span>

M33<\/h3>\n<\/div>

\u00a0<\/p>\n

\""M33,\"<\/div>
Credit: Andrea Maggi, Vicenza, Italy, 20 November 2019.<\/span><\/figcaption><\/div>\n

M33 \u2013 the Triangulum Galaxy \u2013 is a magnificent, albeit faint <\/span>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.<\/p>\n

Locate it by extending the line from M31, the Andromeda Galaxy, through Mirach (Beta (\u03b2<\/span>) Andromedae) for the same distance again (see diagram above).<\/p>\n

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

2<\/span>

Collinder 21<\/h3>\n<\/div>

\u00a0<\/p>\n

Our next target has a charm all its own. To locate it, start at Rasalmothallah (Alpha (\u03b1<\/span>) 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.<\/p>\n

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.
<\/span><\/p>\n

3<\/span>

NGC 672 (and IC 1727)<\/h3>\n<\/div>

\u00a0<\/p>\n

\""NGC\"<\/div>
Credit: G\u00fcnter Kerschhuber \/ CCDGuide.com<\/a><\/span><\/figcaption><\/div>\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.<\/p>\n

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.<\/p>\n

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.<\/p>\n

4<\/span>

NGC 777<\/h3>\n<\/div>

\u00a0<\/p>\n

\""NGC\"<\/div>
Credit: Sloan Digital Sky Survey \/ www.sdss.org<\/a><\/span><\/figcaption><\/div>\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.<\/p>\n

To locate it, imagine the middle line of the Triangulum triangle starting at Rasalmothallah. Head 2.4\u02da along this line from Rasalmothallah where 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.<\/p>\n

The galaxy lies 4.7 arcminutes from TYC2308-585-1 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

5<\/span>

NGC 784<\/h3>\n<\/div>

\u00a0<\/p>\n

\""NGC\"<\/div>
Credit: Harald Strau\u00df \/ CCDGuide.com<\/a><\/span><\/figcaption><\/div>\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.<\/p>\n

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.<\/p>\n

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

6<\/span>

NGC 890<\/h3>\n<\/div>

\u00a0<\/p>\n

\""NGC\"<\/div>
Credit: Donald Pelletier<\/span><\/figcaption><\/div>\n

Our final target is NGC 890, an 11th magnitude lenticular galaxy sitting 1.1\u02da east-southeast of Gamma (\u03b3<\/span>) Trianguli in a barren area of sky.<\/span><\/p>\n

The best strategy to locate it is to use the <\/span>short edge of Triangulum formed by drawing a line from Beta (<\/span>\u03b2<\/span>) through Gamma Trianguli. Keep this line <\/span>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.<\/p>\n

A 250mm scope reveals an object approaching 2 arcminutes in length and 1 arcminute wide under dark-sky conditions.<\/p>\n

Triangulum Majus and Minus<\/strong><\/h1>\n

Back in the 17th century, astronomer Johannes Hevelius split up the Triangulum constellation into two tinier ones: Triangulum Majus and Minus.<\/span><\/p>\n

The little triangle that forms Minus is made up of three 5th magnitude stars that Hevelius was the first to catalogue: 6, 10 and 12 Trianguli.<\/span><\/p>\n

The two triangles were eventually reunited, but two triangles are both nice objects to observe through binoculars.<\/span><\/p>\n

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By Anton Vamplew Published: Tuesday, 05 October 2021 at 12:00 am Some constellations are big, bold and easily recognisable \u2013 like Orion, the Hunter \u2013 and these take pride of place for stargazers. Other, smaller patterns get forgotten. One such constellation is Triangulum, the Triangle. It\u2019s no surprise to discover that Triangulum is made of […]<\/p>\n","protected":false},"author":24,"featured_media":0,"template":"","categories":[1],"acf":{"readingTimeMinutes":"6"},"uagb_featured_image_src":{"full":false,"thumbnail":false,"medium":false,"medium_large":false,"large":false,"1536x1536":false,"2048x2048":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":"By Anton Vamplew Published: Tuesday, 05 October 2021 at 12:00 am Some constellations are big, bold and easily recognisable \u2013 like Orion, the Hunter \u2013 and these take pride of place for stargazers. Other, smaller patterns get forgotten. One such constellation is Triangulum, the Triangle. It\u2019s no surprise to discover that Triangulum is made of…","_links":{"self":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/rss_feed\/25002"}],"collection":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/rss_feed"}],"about":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/types\/rss_feed"}],"author":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/users\/24"}],"wp:attachment":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media?parent=25002"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/categories?post=25002"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}