Constellations
Six patterns that unlock the sky
You don’t need to learn all 88 constellations. Learn these six well and you can star-hop to almost anything else you’ll want to find.
Charts show the sky as you see it facing each pattern: north up, east to the left. Seasons refer to early evening, around 9 pm. Highlighted patterns are well placed in November.
Orion The Hunter
How to find it
Look south on a winter evening for three equal stars in a short, straight row: Orion’s Belt. A bright star sits above and below it on either side.
What to look for
- Betelgeuse, a red supergiant, glows visibly orange next to blue-white Rigel.
- The Orion Nebula (M42) is the misty “star” in the sword below the Belt: visible to the eye, wonderful in binoculars.
- Follow the Belt down-left to Sirius, the brightest star in the night sky.
Leo The Lion
How to find it
Look for a backwards question mark, the Sickle, with bright Regulus at its base. A triangle of stars to the east marks the lion’s hindquarters.
What to look for
- Regulus lies almost exactly on the ecliptic, so the Moon and planets often pass close by.
- Algieba is a lovely golden double star in a small telescope.
- The Leo Triplet, three galaxies in one field, sits below the hindquarters (telescope).
The Big Dipper Part of Ursa Major
How to find it
Seven bright stars in the shape of a ladle, high in the north in spring evenings. From mid-northern latitudes it never sets.
What to look for
- The two stars at the end of the bowl, Merak and Dubhe, point to Polaris, the North Star.
- Mizar, at the bend of the handle, has a faint companion, Alcor, that sharp eyes can split.
- “Arc to Arcturus”: follow the curve of the handle to the bright orange star Arcturus.
The Summer Triangle Vega, Deneb and Altair
How to find it
Three of the brightest stars in summer skies, from three different constellations. Vega is nearly overhead on July evenings; Deneb tops the Northern Cross.
What to look for
- From a dark site the Milky Way runs straight through the triangle.
- Albireo, the foot of the Cross, is a gold-and-blue double star in any small telescope.
- The triangle lingers in the west well into November evenings.
Scorpius The Scorpion
How to find it
Low in the south on summer evenings. Find red Antares, then trace the curved tail down toward the horizon.
What to look for
- Antares means “rival of Mars” for its red colour.
- The globular cluster M4 sits just over a degree from Antares: a fuzzy ball in binoculars.
- From northern Europe and Canada the tip of the tail stays lost in horizon haze.
Cassiopeia The Queen
How to find it
A bright “W” (or “M”) in the north, opposite the Big Dipper across Polaris. It never sets from mid-northern latitudes and is highest on autumn evenings.
What to look for
- The Andromeda Galaxy (M31), 2.5 million light-years away, lies about 15° (a fist and a half) south of Schedar.
- The W sits in the Milky Way and is crowded with open star clusters for binoculars.
- Use it with the Big Dipper as a clock: the two circle Polaris once a day.
Star-hopping
Use the patterns as signposts
Astronomers rarely find things by coordinates. They hop: from a pattern they know, along a line of stars, to the target. The Big Dipper points to Polaris and Arcturus; Orion’s Belt points to Sirius and Aldebaran; Cassiopeia leads to the Andromeda Galaxy. Measure the jumps with your outstretched hand: a fist is about 10°. More on measuring the sky →
Further reading
- Stellarium: free, open-source planetarium software stellarium.org
- Moon Phases NASA Science