Draco Constellation – The Night Sky’s Dragon

In this article, we’ll be sharing with you everything you need to know about the constellation of Draco, 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 Draco

This constellation, whose name means ‘dragon’ in Latin, was associated with a dragon or fierce reptile by many ancient cultures. It was first cataloged by Ptolemy over 2000 years ago.

A common Greek myth is that Draco represents the dragon, Ladon, from the Garden of the Hesperides. The Garden of the Hesperides was a beautiful orchard that belonged to Hera (wife of Zeus) and was guarded by the Hesperides (a group of nymphs).

One of the trees in the orchard bore golden apples that granted immortality to those who ate them. Hera placed the dragon Ladon around that tree to prevent Hesperides from eating the apples.

The Eleventh or Twelfth Labor of Heracles was to steal some of the golden apples. Heracles completed this task after killing Ladon with a poisoned arrow and a saddened Hera placed Ladon in the heavens.

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

Draco the dragon
Draco as depicted in SkySafari 6. Click for full-screen.

Draco has an area of 1083 square degrees making it the 8th largest of the 88 recognized constellations.

Draco is usually depicted as a long dragon and the constellation resembles a stick snake whose triangular head is between the Summer Triangle and Little Dipper of Ursa Minor and whose angular body is between the Little Dipper and the Big Dipper of Ursa Major.

About 5,000 years ago, the Pole Star was Thuban in Draco. The effect of precession, which is the long-term ‘wobble’ in our planet‘s orbit and rotation, means that in the far future (>20,000 years) it will be again.

In the image below, showing the extent of the dragon constellation, note the position of Polaris, the current Pole Star, in the lower middle.

Draco constellation's area, with Polaris shown lower middle.
The area of Draco is shaded. Click for full-screen.

In the next section discover how to find Draco.

How To Find Draco In The Night Sky

This dim, circumpolar constellation is part of the Ursa Major family of constellations and is visible to observers at latitudes between +90° and -15°.

Circumpolar means that Northern Hemisphere observers can see it year-round and all night long. Southern Hemisphere observers can see portions of it during winter.

The constellation of Draco is bordered by the constellations Boötes, Camelopardalis, Cepheus, Cygnus, Hercules, Lyra, Ursa Major, and Ursa Minor.

The constellations bordering Draco
The constellations that border Draco. Click for full-screen.

To find Draco, do a naked-eye search for the Big Dipper. Draw an imaginary line from Phecda to Megrez (~4.5°) which are two stars at the corners of the Big Dipper’s bowl, then extend this line another 15° to Thuban (in Draco’s tail).

Alternatively, do a naked-eye search for the Big Dipper and Little Dipper. Draw an imaginary line from Alkaid (at the tip of the Big Dipper’s handle) to Kochab (the brightest star in the Little Dipper’s bowl) (~25°). Thuban is at the midpoint of this line.

Two routes to find Thurban in Draco from the Big and Little Dippers
Two methods for locating Draco. Click for full-screen.

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

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

Draco’s Brightest Stars

Draco is a large constellation but not especially bright, with only three of its stars brighter than magnitude 3.0: Beta, Gamma, and Eta Draconis.

Altogether, Draco contains almost 40 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 additional information about them.

Named bright stars of Draco
Bright stars of Draco. Stars shown to magnitude 5.0, the most prominent are labeled. Click for full-screen.

Alpha Draconis (Thuban, Dragon’s Tail) – This binary star is located along Draco’s tail and was the Pole Star until ~1900 BC. The primary is a magnitude 3.65 blue-white giant but its secondary is too close to be imaged.

Thuban is 310 light-years away and its name comes from the Arabic name for Draco and means ‘the basilisk’.

Beta Draconis (Rastaban) – This double star is the third brightest star in Draco and marks one of the dragon’s ‘eyes’, alongside Eltanin. The magnitude 2.79 yellow-orange giant primary has a magnitude 14.00 companion that is 4.4 arcseconds away.

Rastaban is 380 light-years away and its name is derived from the Arabic phrase ‘head of the serpent’. 

Gamma Draconis (Eltanin, Etamin) – is another double star and the brightest in Draco at magnitude 2.23. This star marks the location of the second dragon eye. dragon’s eyes.

The primary star is an orange-red giant and it’s 21.0 arcseconds from the magnitude 13.40 secondary.

Eltanin is 154 light-years away. The names ‘Eltanin’ and ‘Etamin’ are derived from the Arabic root for ‘serpent’ or ‘dragon’. 

Delta Draconis (Altais, Nodus Secundus) – The fourth brightest star in Draco is also a double and is 100 light-years away from us.

The magnitude 3.07 orange giant primary star and its magnitude 12.58 secondary are 81.4 arcseconds apart.

Altais is Arabic for ‘the goat’ and ‘Nodus Secundus’ is a Latin reference to this star’s position marking the second of four loops along the dragon’s body.

Epsilon Draconis (Tyl) This variable double star is 148 light-years away. The magnitude 3.83 yellow-orange giant primary and magnitude 6.87 secondary components are 3.2 arcseconds apart.

The primary is an eruptive variable star ranging in magnitude from 3.82 to 3.89.

Zeta Draconis (Aldhibah) – is the fifth brightest star in Draco. It’s a binary system consisting of a magnitude 3.18 blue-white giant primary and a secondary shining at magnitude 4.19 which is 12 AU away. Aldhibah is 328 light-years away.

Eta Draconis (Aldibain) – The second brightest star in Draco shines at magnitude 2.73 magnitude. It is a double star, the primary shines at magnitude 8.20, and is a yellow-orange giant. The secondary, which is 4.4 arcseconds away, shines at magnitude 8.20.

Aldibain is 92 light-years away from Earth.

Theta Draconis – This magnitude 4.01 yellow subgiant star is 69 light-years away. Its mass is 1.2 Solar masses, its diameter is 2.7 Solar diameters and it is 1.1 times hotter than the Sun.

Iota Draconis (Edasich) – This variable double star is 101 light-years away. The magnitude 3.29 orange giant primary and magnitude 8.87 secondary components are 253 arcseconds apart.

The primary is an eruptive variable ranging in magnitude from 3.26 to 3.35. Edasich is a corruption of the Arabic for ‘male hyena’.

Kappa Draconis – is a blue-white giant variable star 490 light-years away from our solar system. It shines at magnitude 3.89 magnitude and is an eruptive variable ranging in magnitude from 3.82 to 4.01.

Lambda Draconis (Gianfar) – Marking the end of the dragon’s tail is this magnitude 3.80 orange-red giant star.

Gianfar is 333 light-years away and a pulsating semi-regular variable ranging in magnitude from 3.78 to 3.86.

Mu Draconis (Arrakis) – This double star is 57 light-years away. The magnitude 5.63 yellow-white main-sequence primary and magnitude 13.70 secondary components are 2.6 arcseconds apart.

Arrakis marks the tip of the dragon’s tongue and its name is Arabic for ‘the trotting camel’ or ‘the dancer’.

Nu1 Draconis (Kuma) – is a variable double star 99 light-years away from Earth. The two components have almost exactly the same magnitudes, 4.88 for the primary and 4.89 for the secondary.

The primary is a yellow-white main-sequence star and is 62.3 arcseconds from its partner. This eruptive variable ranges in magnitude from 4.84 to 4.91.

Xi Draconis (Grumium) – This double star is 113 light-years away. The primary star is an orange giant shining at magnitude 3.74. The secondary star shines at magnitude 13.08 magnitude and is 316 arcseconds from the primary.

Omicron Draconis – is another in a long line of doubles within Draco, this one is 342 light-years away. The magnitude 4.63 primary is an orange giant, the secondary, which is 37.5 arcseconds from the primary, shines at magnitude 8.26.

Pi Draconis – is a double star 229 light-years away, and may be a multiple system with as yet unknown orbital periods.

The magnitude 4.59 yellow-white giant primary and its secondary component are 13.1 arcseconds apart.

Rho Draconis – is 429 light-years away from Earth. Also a double, the two components are 125 arcseconds apart and shine at magnitude 4.51 and 14.60. The primary star is an orange main-sequence type.

Sigma Draconis (Alsafi) – This double star is one of the closest stars to Earth at just 18.8 light-years away. The magnitude 4.67 yellow-orange main-sequence primary and its secondary component are 316 arcseconds apart.

Alsafi is derived from the Arabic term for the tripod nomads use for open-air cooking.

Tau Draconis – is a magnitude 4.44 orange variable star that is 146 light-years away.

Upsilon Draconis – is an orange giant star, 344 light-years from our solar system. It shines at magnitude 4.82 and has about the same mass as our sun but its diameter is 20 times larger, and it’s 19% cooler.

Phi Draconis – This double star is 303 light-years away, shines at magnitude 4.23 and its main component is a blue-white giant. The secondary star shines at magnitude 5.90 and is only 0.6 arcseconds from the primary.

This is a rotating variable whose magnitude ranges from 4.21 to 4.26 over a period of 1.7 days.

Chi Draconis (Minbar, Batentaban Borealis) – is a nearby double star, just 26.3 light-years away. The two components are a magnitude 3.56 yellow main-sequence star and a magnitude 12.10 secondary 178 arcseconds away.

Batentaban Borealis is derived from the Arabic phrase for the ‘Dragon’s Belly’.

Psi1 Draconis (Dziban) – This double star is 75 light-years away. The magnitude 4.57 yellow-white subgiant primary and its magnitude 5.59 secondary component are 29.5 arcseconds apart.

Dziban is derived from the Arabic for ‘the two wolves’.

Omega Draconis – is another bright double star, this system is 76 light-years away. The magnitude 4.78 yellow-white main-sequence primary and magnitude 13.20 secondary components are too close to be optically split.

42 Draconis (Fafnir) – This double star is 315 light-years away. The magnitude 4.82 orange giant primary and its magnitude 13.00 secondary component are too close to be optically separated.

Star Hopping From Draco

Draco is the starting point for a few well-known star hops.

M102 – Identify Edasich (the fourth star at the tail-end of Draco), hop ~4° southwest to M102.

M102, the Spindle Galaxy, in Draco.
Find M102 4° southwest of Edasich

NGC 6503 – Identify the stars Aldhibah (Zeta Draconis) and Chi Draconis (in the northwestern half of Draco) which are ~6° apart. The spiral galaxy NGC 6503, which shines at magnitude 10, is just past midway between them, slightly closer to Chi Draconis.

NGC 6543 – Using the same two stars as for NGC 6503, imagine they are the base of a right-angled triangle. The Cat’s Eye Nebula – NGC 6543 – sits at the right-angled corner (see the dotted orange lines in the star chart below).

See the image below for a simple finder chart showing the locations of NGC 6503 and 6543. Stars are shown to magnitude 7.0.

Finding NGC 6503 and 6543 in Draco constellation
Finding NGC 6503 and 6543 in Draco. Click for full-screen.

Objects To See Within Draco

Draco contains one Messier object and some deep sky objects suitable for small telescope users.

M102 (NGC 5866, Spindle Galaxy) – This spiral galaxy has a magnitude of 9.81 and an apparent size of 6.3 x 2.7 arcminutes. It’s 47 million light-years away and is at right ascension 15h 06m 30s and declination 55° 45’ 48” (J2000.0).

NGC 4236 – This barred spiral galaxy has a magnitude of 9.71 and an apparent size of 23.5 x 6.8  arcminutes. It’s 14 million light-years away and is at right ascension 12h 16m 42s and declination 69° 27’ 45”.

NGC 6503 – This spiral galaxy has a magnitude of 10.09 and an apparent size of 5.9 x 2.0 arcminutes. It’s 20 million light-years away and is at right ascension 17h 49m 27s and declination 70° 08’ 40”.

NGC 6543 (Cat’s Eye Nebula, Caldwell 6) – This planetary nebula has a magnitude of 8.10 and an apparent size of 0.4 x 0.3 arcminutes. It’s 3,100 light-years away and is at right ascension 17h 58m 33s and declination 66° 37’ 58”.

Summary

Draco is a large, dim constellation with many notable stars and some deep sky objects for small telescope users.

Look for its winding body near the Big and Little Dippers and enjoy its wonders all year round.


Written by Tanya C. Forde