With June bringing the summer solstice, the nights are gradually beginning to lengthen again. The skies remain bright, but a tapestry of gorgeous constellations shines through, offering stories and starlight from the distant past. Here are some of the best and most beautiful constellations to look out for this summer.
Okay, this first pattern isn’t really a constellation, but it is a very helpful signpost in the summer sky. The Summer Triangle is an asterism – a pattern formed from bright stars that is not formally a constellation. True to its name, it takes the shape of a triangle formed from three summer stars, which are each members of different constellations. Seen high in the southern sky around midnight, it is a large shape that becomes visible as the sky begins to darken, well before the fainter stars around it or inside it. Let’s look at each of its stars and their parent constellations.
Top-left (northeast) Deneb
Deneb, meaning ‘tail’, is the brightest star in Cygnus the Swan. One of many birds among the constellations, Cygnus is perhaps the most dramatic, seen flying along the Milky Way with wings spread wide. The swan’s long neck reaches into the centre of the Summer Triangle, culminating with the star Albireo – the “hen’s beak” – a stunning blue-gold double. Cygnus is connected to a story in which Zeus, the king of the gods in Greek mythology, turned himself into a swan to win the affection of Leda, queen of Sparta.
Top-right (northwest) Vega
The constellation Lyra the Lyre (Harp) holds the honour of being the only musical instrument in the stars. Said to be owned by the legendary Greek hero and bard Orpheus, its string box is formed from a rhombus of stars just beneath the brilliant Vega. Lyra is home to the famous ‘Double Double’ – Epsilon Lyrae, which invites exploration with a telescope. At low magnifications it appears to be a double star, but zooming in we can see that each member is also a tightly bound double star in its own right.
Bottom (south) Altair
Aquila the Eagle hosts Altair at the southern tip of the Summer Triangle. A proud bird not quite as large as Cygnus, it represents an eagle Zeus dispatched to Earth to kidnap the shepherd boy Ganymede. Its brightest star Altair is the nearest of the three in the triangle, at a distance of just 16.7 light-years. We see it now as it appeared in October of 2005, when the American civil rights activist Rosa Parks passed away aged 92.
We can use the Summer Triangle as a reference point for finding many more constellations over the next few months.
Delphinus the Dolphin
A very compact and cute constellation, Delphinus sits just to the east (left) of Aquila, adjacent to the Summer Triangle. It takes the form of a leaping dolphin, inspired by the story of Arion – a Greek poet whose life was saved by a dolphin after he was thrown overboard and left for dead by a mutinous crew. Delphinus is relatively faint but rewarding to pick out and easy to spot with practise.
The most famed hero of the ancient world, Hercules (or Heracles) is more than worthy of his own constellation, although its sprawling and sparse nature can be tricky to pick out. Tracing a line from Deneb to Vega, then continuing for about the same distance, you will arrive at the ‘Keystone’ asterism at the heart of Hercules. Scan here with binoculars or a telescope to spot a fuzzy looking ‘star’ – the Great Globular Cluster in Hercules, which is a collection of hundreds of thousands of stars around 25,000 light-years away!
Corona Borealis (the Northern Crown)
Further over to the west (right) of Hercules is a pleasing semi-circular pattern with one star (called Alphecca) appearing noticeably brighter than all the others. This is Corona Borealis, the crown of Ariadne, princes of Crete. It is said that she donated it to Theseus, and he used its radiant light to find his way out of the Minotaur’s labyrinth. Corona Borealis is among the smallest constellations in the sky – a little gem in the summer sky.
Boötes the Herdsman
On summer nights, Arcturus rules the western sky after sunset. As the fourth brightest star in the entire sky, it has no challengers at this time of year. The name of this star means “Guard” and its name aligns with the identity of its parent constellation: Boötes, the keeper of the bears (those being Ursa Major and Ursa Minor in the northern sky.) Boötes has a shape reminiscent of a kite on a string and stands upright in the west next to the Northern Crown.
Sagittarius and the ‘Teapot’
Look to the southwest (lower right) of the Summer Triangle, just above the southern horizon around midnight, and you may spot a familiar shape in the stars. The Teapot asterism is formed from eight stars in the constellation Sagittarius – the archer-centaur, sometimes identified as the character Chiron in Greek mythology. In the UK, this constellation only partially clears the horizon, but the Teapot is easy to find. It pours to the west, with the centre of the Milky Way Galaxy being found just beyond the spout. Continue looking to the right and find the red-orange star Antares, the heart of its zodiacal neighbour Scorpius the Scorpion, another constellation that dips below our southern horizon.
Tom Kerss is an astronomer, astrophotographer, writer and speaker, specialising in the rewarding task of connecting people to their shared universe. He is the author of Northern Lights, Moongazing, Stargazing and You Can Explore the Universe, all of which are available now.