5. Vega

The name Vega derives from the Arabic word for Swooping Eagle or Vulture. Vega is the luminary of Lyra, the Harp, a small but prominent constellation that is home to the Ring Nebula and the star Epsilon Lyrae.

The Ring is a luminous shell of gas that was ejected from an old star. It resembles a smoke ring or donut. Epsilon Lyrae appears to the naked-eye as a double star, but through a small telescope you can see that the two individual stars are themselves double! Epsilon Lyrae is popularly known as the "double double."

Vega is a hydrogen-burning dwarf star, 54 times more luminous and 1.5 times more massive than the Sun. At 25 light-years away, it is relatively close to us. It shines, therefore, with a magnitude of 0.03 in the night sky.

In 1984, a disk of cool gas surrounding Vega was discovered -- the first of its kind. The disk extends 70 Earth-Sun distances from the star. The discovery was important because a similar disk is theorized to have played an integral role in planet development within our own solar system.

Together with the bright stars Altair and Deneb, Vega forms the popular Summer Triangle asterism that announces the beginning of summer in the Northern Hemisphere. The asterism crosses the hazy band of the Milky Way, which is split into two near Deneb by a large dust cloud called the Cygnus Rift.

This area of the sky is ideal for sweeping with binoculars of any size in dark-sky conditions.

Vega was the first star to be photographed, on the night of July 16-17, 1850 by photographer J.A. Whipple. With the daguerreotype camera used at the time, he made an exposure of 100 seconds using a 15-inch refractor telescope at Harvard University. Fainter stars (those of 2^nd magnitude and dimmer) would not have registered at all given the technology of the time.

Vega used to be the North Star, but 12,000 years of Earth’s precession has altered its place in the celestial sphere. Precession is the 26,000 year wobble of the Earth’s axis due to the gravitational attraction of the Sun and Moon on the Earth’s equatorial bulge. In another 14,000 years, Vega will be the North Star once again. [Vega Map]