# Rastaban (Beta Draconis)

Rastaban (Beta Draconis) is a star in the constellation Draco, magnitude 2.8.

**The Dragon’s head — a yellow star poised between giant and supergiant.**

Rastaban means “the head of the dragon” in Arabic, a name it has shared with its neighbour Eltanin, Gamma Draconis. Arab stargazers also counted it among the Mother Camels, five stars of Draco guarding a camel’s foal — a group later called Quinque Dromedarii, the five dromedaries. Another old name, Alwaid, comes from the Arabic for “the old mother camels”.

The star sits on the border between bright giants and supergiants, and its spectrum is a standard for that [class](https://astropilot.space/glossary/spectral-type). It has about six times the Sun’s mass and roughly 40 times its width, and shines some 950 times as brightly. At about 65 million years old it is churning material from deep inside up to its surface for the first time, in what astronomers call the first dredge-up.

A very faint companion, about 11 magnitudes dimmer, circles it perhaps once every four thousand years.

Rastaban (Beta Draconis) is 380 light-years away: the light we see from it set off around 1645, 35 years after Galileo first turned a telescope to the sky.

## Did you know?

- **Barely flickering.** Rastaban sits on or near the instability strip where stars such as Cepheids pulsate, yet it varies by only about a hundredth of a magnitude — confirmed by Gabriel Cristian Neagu using TESS and Hipparcos data.
- **The Celestial Flail.** In Chinese astronomy it is the third star of Tiān Bàng, the Celestial Flail, made of the four stars of the Dragon’s head and Iota Herculis.
- **A glowing upper atmosphere.** Its chromosphere, the layer above the visible surface, is unusually active, giving off X-rays and far-ultraviolet light.

A yellow star of magnitude 2.8, one of the four stars that form the Dragon’s head, north-west of brilliant Vega. Compare its yellow with the deeper orange of Eltanin, the head’s brightest star, about 4 degrees to the east.

## When and where to see it

It is best placed in the evening sky around July, when it crosses the meridian at about 10 pm local time (around midnight in June). It can be seen from everywhere north of 38°S and never sets north of 38°N.

At its highest it stands 88° up from 50°N, 73° up from 35°N, 38° up from the equator, 3° up from 35°S.

## Facts

- Type: Star
- Constellation: Draco
- Designations: Beta Draconis, β Dra, 23 Dra, HR 6536, HD 159181, HIP 85670
- Magnitude: 2.8
- Position: RA 17h 30.4m, Dec +52° 18′ (J2000)
- Spectral type: G2Ib-IIa
- Colour: orange (B−V 0.98)
- Distance: 380 light-years
- Discovered: Known since antiquity

Open AstroPilot to see when Rastaban (Beta Draconis) is highest tonight from your location, how easy it is with your telescope or binoculars, and an eyepiece view. https://astropilot.space/object/rastaban