Auriga Constellation – Midnight’s Charioteer

In this article, we’ll be sharing with you everything you need to know about the constellation Auriga, including how to find it, deep space objects contained within it, and how to use it to find other night sky objects more easily.

The Constellation of Auriga

Auriga is one of the constellations that Greek astronomer Ptolemy cataloged over 2000 years ago and its name is Latin for “the charioteer”.

A popular Greek myth associates Auriga with Erichthonius, King of Athens. Erichthonius was the son of fire god Hephaestus and was raised by the goddess Athena. Erichthonius is credited with inventing the quadriga, the four-horse chariot, and Zeus was so impressed by this feat that he places Erichthonius in the heavens.

In another Greek myth, Auriga represents Myrtilus, son of Hermes and servant of King Oenomaus of Pisa. Hermes placed Myrtilus in the heavens after he was killed trying to with the hand of Princess Hippodamia in a chariot race.

To help you spot Auriga, here’s what SkySafari 6 shows.

Mythical figure depiction behind the constellation of Auriga
The charioteer, Auriga. Click for full-screen.

Auriga has an area of 657 square degrees making it the 21st largest of the 88 recognized constellations.

Auriga is shaped like an irregular pentagon and is often depicted as a man holding the reins of a chariot in his left hand and holding a goat and its kids in his right hand.

This constellation is known for its bright star Capella, which is part of the Winter Hexagon asterism. Auriga is also known for a smaller, triangular asterism near Capella called ‘The Kids’, which consists of the stars Al Anz, Haedus I, and Haedus II.

The most recognizable part of the constellation is the pentagon because all five of its stars are bright and it takes up a large swathe of winter’s night sky.

Shaded area for Auriga
The shaded area shows Auriga’s extent. Click for full-screen.

In the next section discover how to find Auriga.

How To Find Auriga In The Night Sky

Auriga is part of the Perseus family of constellations and is visible to observers at latitudes between +90° and -40°.

Northern Hemisphere observers can see it in the evening sky from October to May. The best views are enjoyed in February and March when the constellation is directly overhead. Southern Hemisphere observers can see it during the early months of the year

The constellation of Auriga is bordered by the constellations Camelopardalis, Gemini, Lynx, Perseus, and Taurus.

The boundary lines of Auriga and its bordering constellations.
Auriga is bordered by five other constellations. Click for full-screen.

Auriga is obvious enough to find with a naked-eye search. Its five principal stars form a large and obvious irregular pentagon high in winter’s night sky. However, if you’re struggling to see it, use the Big Dipper of Ursa Major, or Orion to help you locate it.

In the Big Dipper, draw an imaginary line from Megrez to Dubhe (~10°), then extend this line ~50° to Capella.

Using the Big Dipper to find Capella in Auriga.
Use the Big Dipper to point to Auriga. Click for full-screen.

Alternatively, do a naked-eye search for Orion. Draw an imaginary line from Alnitak in Orion’s Belt to Meissa at Orion’s head (~11°) then extend this line ~36° to Capella.

A guide to finding Capella in Auriga from Orion.
How to find Auriga from Orion. Click for full-screen.

You can measure all of these distances with your hand at arm’s length.

To find Andromeda’s exact position for your location on any night, use astronomy software such as Stellarium (free) or SkySafari 6.

Auriga’s Brightest Stars

Auriga is a large and bright constellation with around 25 stars brighter than magnitude 5.0. The star chart below, from SkySafari 6, shows these for reference. The more interesting ones are listed below that with some information about them.

The brightest stars in Auriga with their names or catalo designations.
The brightest stars of Auriga. Click for full-screen.

Alpha Aurigae (Capella) – This double star is the brightest star in Auriga and the sixth brightest star in the night sky.

It marks Auriga’s left shoulder and is the northernmost star in Auriga’s pentagon. The magnitude 0.07 yellow-orange giant primary has a companion which shines at magnitude 17.10 but is too close to be separated visually due to the brightness of the primary.

Capella means ‘little she-goat’ in Latin and is 42 light-years away.

Beta Aurigae (Menkalinan) – This variable double star is the second brightest star in Auriga and marks the northeast corner of Auriga’s pentagon.

The magnitude 1.89 white main-sequence primary and the magnitude 10.86 main-sequence secondary components are 187.2 arcseconds apart.

Menkalinan is 82 light-years from us and is an eclipsing variable star that ranges in magnitude from 1.89 to 1.98 every four days. Its name means ‘the shoulder of the rein-holder’ in Arabic.

Beta Tauri, Elnath (Historically: Gamma Aurigae) – This double star is the second brightest star in Taurus (the designation Gamma Aurigae is no longer used) and marks both the tip of Taurus’s northern horn and the southwest corner of Auriga’s pentagon.

Technically, Elnath is a part of the constellation of Taurus but we’ve included it here because it is part of the pentagon asterism.

The primary star shines at magnitude 1.67 and is a blue-white giant. The secondary component is 33 arcseconds away. This star is 130 light-years from our solar system.

Elnath is Arabic for ‘the butting one’.

Delta Aurigae – This double star is the northernmost star in Auriga. The magnitude 3.73 orange giant primary and magnitude 10.60 secondary components are 124.4 arcseconds apart. Delta Aurigae is 140 light-years away.

Epsilon Aurigae (Almaaz, Al Anz) – Is the fifth brightest star in Auriga and the brightest not to form part of the pentagon. It’s the northernmost star in ‘The Kids’ asterism.

A view of The Kids asterism at the west side of Auriga
The Kids asterism, shown orange.

Al Anz is a magnitude 3.02 yellow supergiant. It is also a double star with a magnitude 14.00 secondary component too close to be spied in the best backyard telescope.

This eclipsing variable ranges in magnitude from 2.92 to 3.88 over a period of 27 years.

Al Anz is 2,100 light-years away and its name is Arabic for ‘the he-goat’.

Zeta Aurigae (Haedus I) – Lies 850 light-years away from us and is a variable double star.

The primary component shines at magnitude 3.75 and is a bright orange giant. The secondary is a blue main-sequence star which is too close to be seen visually.

This eclipsing variable ranges in magnitude from 3.70 to 3.97 over 2.66 years as the smaller component passes behind the primary.

Haedus I is the westernmost star in The Kids asterism and its name also means ‘kids’ in Latin.

Eta Aurigae (Haedus II) – Falls on the pentagon between the brighter Capella and Al Kab. It is also the easternmost star in The Kids asterism.

Haedus II is an eruptive variable star 220 light-years away from us. This blue-white main-sequence sun ranges in magnitude from 3.16 to 3.19.

Theta Aurigae – This variable double star is the third brightest in Auriga and marks the southeast corner of Auriga’s pentagon. The magnitude 2.65 primary is a blue-white main-sequence type, its white secondary is 4.2 arcseconds away and shines at 7.20. This double star is 173 light-years away from us.

This rotating variable ranges in magnitude from 2.62 to 2.70 with a period of 3.6 days.

Iota Aurigae (Hassaleh, Al Kab) – This magnitude 2.68 orange-red giant is the fourth brightest star in Auriga and marks the northwest corner of its pentagon. It’s an eruptive variable whose magnitude ranges from 2.63 to 2.78.

Al Kab is 510 light-years away. Its name is a shortened form of the Arabic phrase meaning ‘the shoulder of the rein holder’.

Kappa Aurigae – Lies towards the southern boundary of Auriga with Gemini. Kappa Aur. is an orange giant shining at magnitude 4.32 and is 177 light-years away.

Lambda Aurigae – Inside the pentagon is this double star that is 41 light-years away from us. The primary is a magnitude 4.69 yellow subgiant, the secondary shines at magnitude 13.39, and they are 29.1 arcseconds apart.

Mu Aurigae – Nearby Lambda is this double star, although it is much farther away from us at 153 light-years. The magnitude 4.82 primary is a white main-sequence star primary. The secondary component is 0.1 arcseconds away but has not had further data determined.

Nu Aurigae – This double star is 66 light-years away and located near the easter pentagon point of Theta Aur. The two component stars are 55.8 arcseconds apart and consist of a magnitude 3.97 orange giant primary and a dwarf secondary shining at magnitude 11.40 magnitude.

Xi Aurigae – Is very close to the northern border with Camelopardalis. It’s a magnitude 4.96 magnitude white main-sequence star, positioned 238 light-years away from Earth. Its mass is 2.5 Solar masses, its diameter is 3.0 Solar diameters and it’s 1.6 times hotter than the Sun.

Pi Aurigae – Can be seen on the eastern side of Auriga’s triangular ‘hat’, near Menkakainan. It is a magnitude 4.32 orange-red giant some 840 light-years away. It’s also a pulsating variable that ranges in magnitude from 4.23 to 4.34.

Sigma Aurigae – This double star is almost perfectly centered in Auriga’s pentagon. It’s 467 light-years away from us and shines at magnitude 4.98. This star’s components are an orange giant primary and a magnitude 12.00 secondary that are 8.1 arcseconds apart.

Tau Aurigae – This double star is 213 light-years away. The magnitude 4.51 yellow-orange giant primary and magnitude 11.60 secondary components are 42.5 arcseconds apart.

Upsilon Aurigae – A couple of degrees west of Theta Aur. is this magnitude 4.73 orange-red giant. It is 457 light-years away from Earth.

Phi Aurigae – This double star is 453 light-years away. The orange giant primary shines at magnitude 5.05, while its secondary is a much fainter magnitude 14.60. The two stars are 23.6 arcseconds apart.

Chi Aurigae – This 4.73 magnitude, yellow-white supergiant is 2984 light-years away. This eruptive variable has a mass of 20.0 Solar masses, a diameter of 25.7 Solar diameters and it’s 2.4 times hotter than the Sun.

Psi1 Aurigae – Lies out towards the stepped northeastern boundary with Lynx constellation. This orange-red supergiant is 2954 light-years away and shines at magnitude 4.94. It’s a pulsating variable ranging in magnitude from 4.67 to 5.70 over 175.0 days.

Psi2 Aurigae – Is almost equidistant from the shapes of Auriga, Lynx, and Gemini. It’s a double star lying 416 light-years away. The magnitude 4.78 orange giant primary and its magnitude 11.47 secondary component are 51.3 arcseconds apart.

Discover how many stars are within 1,000 light-years of Earth (opens new tab)

Omega Aurigae – This double star is 170 light-years away. The magnitude 4.98 white main-sequence primary and magnitude 8.21 secondary components are 4.8 arcseconds apart.

14 Aurigae – Found near the southwestern base of the pentagon, this variable double star is 286 light-years away. The magnitude 4.98 yellow-white main-sequence primary and magnitude 10.90 secondary components are 9.8 arcseconds apart.

It’s a pulsating variable ranging in magnitude from 4.94 to 5.08 over 0.088088 days, which is 2 hours and seven minutes.

Star Hopping From Auriga

Auriga is the starting point for some well-known star hops.

M37– Identify Capella then hop to Theta Aurigae and Elnath on the opposite side of Capella’s pentagon. Imagine Theta Aurigae and Elnath are at the base of a long, thin triangle pointing away from Capella. M37 is at the third corner of this triangle, ~5° from Theta Aurigae and ~7° from Elnath.

Here’s our full guide to finding and observing M37 (opens a new tab)

M36 – Identify M37 then hop ~4° west-northwest to M36 in the interior of Auriga.

M38 – Identify M36 then hop ~2° northwest to M38 in the interior of Auriga.

The location of the open clusters M36, 37, and 38 in Auriga.
Locations of M36, M37, amnd M38 in Auriga. Click for full-screen.

Objects To See Within Auriga

Auriga contains three Messier objects and a few other deep sky objects suitable for small telescope users. Some of the best of these are the three open star clusters which form part of the outer Milky Way.

We can see the Milky Way running through Auriga. When we look at it, we’re actually out into deeper space across the arms of our galaxy. Its center, home of a supermassive black hole, is in the opposite direction, in the constellation of Sagittarius.

M36 (NGC 1960, Pinwheel Cluster) – This open cluster has a magnitude of 6.00 and an apparent size of 10.0 arcminutes. It’s 4,300 light-years away and is at right ascension 05h 36m 18s and declination 34° 08’ 00” (J2000.0).

M37 (NGC 2092) – This open cluster has a magnitude of 5.59 and an apparent size of 14.0 arcminutes. It’s 4,500 light-years away and is at right ascension 05h 52m 18s and declination 32° 33’ 00”.

This is a particularly wonderful view, even inside a smaller telescope or astronomy binoculars.

M38 (NGC 1912, Starfish Cluster) – This open cluster has a magnitude of 6.40 and an apparent size of 20.0 arcminutes. It’s 4,600 light-years away and is at right ascension 05h 28m 40s and declination 35° 50’ 00”.

IC 405 (Flaming Star Nebula, Caldwell 31) – This bright nebula has a magnitude of 10.00 and an apparent size of 30 x 19 arcminutes. It’s 1,400 light-years away and is at right ascension 05h 16m 12s and declination 34° 16’ 12”.

IC 410 – This bright nebula has a magnitude of 10.00 and an apparent size of 40 x 30 arcminutes. It’s 1,000 light-years away and is at right ascension 05h 22m 36s and declination 33° 31’ 00”.

Summary

Auriga is the 21st largest constellation and its pentagon of bright stars is a waymarker for winter night skies.

There are several bright double stars to enjoy and three of the best open clusters within its boundaries.

Hop to it from the Big Dipper or Orion this winter.


Written by Tanya C. Forde