Draco: Dragons and Serpents in the Stars

## Draco: The Celestial Dragon

Draco is a large circumpolar constellation that winds between Ursa Major and Ursa Minor, covering 1,083 square degrees. Though its stars are mostly faint, its mythological significance is immense — it once held the north celestial pole.

### Stars of Draco

| Star | Name | Magnitude | Spectral Type | Distance |
|------|------|-----------|---------------|----------|
| Alpha Dra | Thuban | +3.65 | A0 III | 303 ly |
| Gamma Dra | Eltanin | +2.24 | K5 III | 148 ly |
| Beta Dra | Rastaban | +2.79 | G2 Ib-IIa | 362 ly |
| Eta Dra | Athebyne | +2.73 | G8 III | 88 ly |
| Delta Dra | Altais | +3.07 | G9 III | 97 ly |

Eltanin (Gamma Draconis), not Thuban, is actually the brightest star in the constellation. It was the subject of a famous observation by James Bradley in 1725 that led to the discovery of the aberration of light, confirming Earth's orbital motion.

### Thuban: The Ancient Pole Star

**Thuban** (Alpha Draconis) was the pole star around 2700 BCE, during the construction of the Great Pyramid at Giza. The descending passage of the Great Pyramid was aligned to point directly at Thuban. Due to the 25,772-year precession cycle, Thuban will return to within 0.5 degrees of the pole around 20,346 CE.

### Greek Mythology: Ladon

In Greek myth, Draco represents Ladon, the hundred-headed dragon who guarded the golden apples in the Garden of the Hesperides. Heracles (Hercules) slew Ladon as his eleventh labor. The nearby constellation Hercules depicts the hero with one foot on the dragon's head — Hercules' foot star (Alpha Herculis, Rasalgethi) is adjacent to Draco's head.

### Chinese Astronomy

In Chinese star lore, Draco's stars belong to several different asterisms within the Purple Forbidden Enclosure (Zi Wei Yuan), the celestial region surrounding the north pole that represented the Emperor's palace. The "Right Wall" and "Left Wall" of the enclosure pass through Draco's stars.

### Babylonian Origins

The Babylonians saw a dragon called Tiamat in these stars. In the creation epic Enuma Elish, the god Marduk slew the primordial dragon Tiamat and used her body to create the heavens and Earth — one of the oldest creation narratives connected to a constellation.

### Notable Deep-Sky Object

The **Cat's Eye Nebula** (NGC 6543), one of the most complex planetary nebulae known, lies within Draco at a distance of about 3,300 light-years. Hubble Space Telescope images reveal intricate concentric shells, jets, and knots of glowing gas ejected by a dying star.