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How to See the Summer Triangle With A Telescope?

Sometimes stargazing does not need to memorize all the constellations because like the Summer Triangle, the best star patterns to observe are not always constellations but asterisms. An asterism is a pattern of stars not included in the official 88 constellations.  The Summer Triangle is an asterism, made of 3 bright stars Vega, Deneb, and Altair though in the 3 different constellations. It is available mostly on summer nights in the northern hemisphere. 

Several star maps like Stellarium, GoogleSky, Sky Safari, etc. are available online. The Summer Triangle is visible for most of the year, but for beginners, the apps can be a great aid.

What is Summer Triangle?

The Summer Triangle is one of the most famous asterisms in the sky and is easy to spot on a clear summer night. The stars that make up the Summer Triangle are amazing individually as well. Vega is the fifth brightest star in the night sky and is only about 25 light-years away from Earth. Deneb is one of the most distant stars that can be seen with the naked eye and is about 2,600 light-years away. Altair is one of the closest stars to Earth that is similar in size to our sun. The Summer Triangle is not a constellation, but rather an asterism that spans across three different constellations. There are several constellations and deep-sky objects located inside the Summer Triangle, including Sagitta, Delphinus, and Vulpecula. The Summer Triangle is visible all year round, but is most visible in the summer months when it is high in the sky by the time it gets dark. The Summer Triangle asterism has been recognized for thousands of years and has been mentioned in various cultures and mythologies. In Greek mythology, the Summer Triangle was associated with the god Zeus and his eagle, Aquila. In Chinese astronomy, the stars of the Summer Triangle were associated with the “Three Enclosures,” which represented the imperial palace and the celestial marketplace.

Can you see Summer Triangle with a telescope?

Yes, the Summer Triangle can be seen with a telescope. The key features that make it visible include its formation by stars from three different constellations, its bright stars Deneb, Vega, and Altair, and its hourglass shape visible in small telescopes. The purpose of using a telescope to view the Summer Triangle is to see the celestial objects within it more clearly and in greater detail, enhancing the stargazing experience.

The Summer Triangle is significant for stargazing with a telescope as it acts as a guiding star map, making it easier to locate other celestial objects in the night sky. Light pollution can significantly impact the quality of viewing the Summer Triangle with a telescope, as it reduces visibility and affects the ability to see faint objects in the night sky. Dark adaptation is essential in observing the Summer Triangle with a telescope as it allows your eyes to adjust to the darkness, enabling you to see faint celestial objects more clearly.

The recommended magnification for viewing the Summer Triangle with a telescope is around 200x in a four-inch aperture telescope. The recommended aperture for viewing the Summer Triangle with a telescope is between 5-8 inches (125 to 200 mm) for focal lengths of 1000 mm or less. The best type of telescope for viewing the Summer Triangle would be the Celestron NexStar 8 SE Computerized Telescope or the Celestron NexStar 4SE.

Quick Guide to Observe the Big Dipper

The majority of the year can be spent observing the Summer Triangle. The vast Summer Triangle crosses the Milky Way’s Great Rift, touches more than two constellations, and extends across it. But tracking it is simple. Find the area of the sky that is the darkest and away from the city’s lights. The stars are so bright that you may observe them wearing a Bahtinov mask. However, the Summer Triangle is visible with the unaided eye. The views are crystal bright and clean when using a 2-4 inch telescope. With a modest magnification and a long focus length object, center the Summer Triangle on the finderscope.

How to find The Summer Triangle?

The Summer Triangle is huge and touches more than two constellations and spans across the Great Rift of the Milky Way. However, it is not hard to track.

  1. Vega is the second brightest star (after Arcturus) on the northern horizon. You will find this star without any effort.
  2. Then travel over to the constellation named Cygnus and look for the bright star Deneb (number 2 star in the star pattern and brightest in the Northern Cross)
  3. Then move to the summer constellation Aquilla the Eagle and complete the pattern of the triangle. The second brightest star there is Altair with 2 other fainter stars on either side of it.

What is the best time to observe the Summer Triangle?

The Summer Triangle is observable for most of the year. It begins to reveal its 3 bright stars in June on the eastern horizon whenever the night falls. This is the best time to observe the Summer Triangle as it is available in the sky throughout the night. At midtime or the night sky gets completely dark and only the three stars will be available. In July and August at around midnight, it shines directly overhead. The position of Altair, Deneb, and Vega changes with the change of seasons. By the late fall and winter, the three stars rise high on the western horizon and set by about 10 pm.

What can you see with The Summer Triangle through a telescope?

Lyra Constellation

  • The Summer Triangle spans the constellation Lyra. You will find Epsilon (ε) Lyrae, the naked eyes double with a magnitude from +4.7 to +5.
  • Zeta (ζ) Lyrae, a double star will be visible with a small telescope. Beta (β) Lyrae, or Sheliak is an eclipsing binary orbiting each other on a 13 days period. 
  • Gamma (γ) (mag . + 3.2 ) and kappa (κ) (mag +4.3) make interesting light-curve for Sheliak.

Cygnus Constellation

  • Cygnus, one of the main constellations of the northern sky looks like a kite.
  • The stars located on the cross are  Sadr (gamma or γ), Gienah (epsilon or ε), delta (δ), and Albireo (beta or β)
  • The reddest star there is a Mira variable named U Cygni.
  • You will find luminous and remote star P Cygni
  • The Milky Way is also there through Cygnus.
  • NGC 7000 (or Caldwell 20 ) and North America Nebula are also stunning to see with a telescope there.

Aquila Constellation

  • Aquila, the celestial Eagle includes  Altair (alpha or α), reddish Tarazed (gamma or γ), and Alshain (beta or β)
  • You will find Delphinus with Equuleus (the Foal), the small groups of Sagitta (the Arrow), and Vulpecula (the Fox).


  • The main-sequence blueish-white star Vega is stunningly bright with a magnitude of 0.03. It is 40 times brighter than our sun.
  • Vega can be used for star alignment too.


  • Deneb or Alpha Cygni is one of the brightest stars with a magnitude of 1.25 and is located in the constellation Cygnus.


  • Altair is the most southerly star in the Summer Triangle asterism and it is also the first to disappear in late November.

M56 (NGC 6779)

  • A globular cluster in the constellation Lyra with a magnitude of +5.

M27 (NGC 6853)

  • Messier 57 (The Ring Nebula) in the constellation Lyra is remarkable for its shape not far from Vega.

How to use Summer Triangle as nature’s seasonal calendar?

You can identify the seasons using the Summer Triangle:

  • When the three stars shine in the eastern twilight dusk in the middle to late June, it indicates that spring has ebbed into summer.
  • When the three stars are high in the south to overhead at dusk and early evening, it is an indication that summer is giving way to fall.

2 Tips to observe The Summer Triangle in the best way.

  • Find out the darkest sky away from the city lights. It is better to head for the country or a village on a moonless night.
  • You can use a Bahtinov mask while observing the stars as they are very bright. It helps a lot in focusing.

What telescope to see The Summer Triangle?

Celestron StarSense Explorer LT 80AZ Refractor and Sky-Watcher Classic 6-inch Dobsonian are great telescopes to see The Summer Triangle. A list of telescopes has more telescope options that can see The Summer Triangle very clearly.

What size telescope to see The Summer Triangle?

The Summer Triangle can be seen with the naked eye. Using binoculars or a telescope makes the views clear and sharp. Even with the 2.5-inch aperture telescope, it looks really great—however, the larger the aperture, the better the view.

What magnification is required to see The Summer Triangle?

25X magnification is more than enough to see the stars of The Summer Triangle.

Enjoying The Summer Triangle? Here are other things to see with your telescope

There are other popular asterisms in the night sky that looks great with a telescope. Orion’s Belt, The Big Dipper or The Plough, Kemble’s Cascade, The Diamond Cross, and so on. Viewing The Big Dipper Through A Telescope and Viewing Orion Nebula Through A Telescope can guide us to find out these stars in the sky. You can also choose any object from ‘List of things to see with a telescope’ to plan for a great sky observation session.