Aldebaran is a red giant star, with a diameter about forty times
the Sun's. It is a variable star and its visual magnitude is +0.85 at maximum,
therefore it is one of the brightest stars in the northern hemisphere.
Aldebaran is one of the four Royal Stars of the ancient Persians.
Greeks named it Torch, whereas the name Aldebaran - of arabic
origin - means "he who follows", because it apparently
follows the Pleiades in the sky.
 |
The Taurus constellation from Uranographia by Johannes
Hevelius (1690). Aldebaran is the star near the left eye of the bull. |
 |
The spectrum of Aldebaran (spectral type K5) from the Hubble
Space Telescope. The spectrum was obtained with a 20-minute medium-resolution ultraviolet exposure using the Goddard High Resolution Spectrograph. It shows emission features arised from the chromosphere, a region of warm gas (10,000 K) which lies above the "visible surface" of the star. |