The Star Vega (alpha Lyrae)


Information About Star Vega

The Star Vega; named after Arcturus, is the second brightest star in the northern sky. Around midnight it can be seen with Deneb in the Swan and Altair in the Eagle Summer Triangle. For years it has been the standard to which the brightness of all other objects was determined. It is now lost; but Wega still fascinates to this day both amateur and professional astronomers. However, this well-known major star still has not divulged all its secrets.


Alpha Lyrae (Star Vega) Facts and Figures 

  • Constellation: Lier
  • Scientific name: Alpha Lyrae
  • Position: right ascension 18h36m56s.33, declination + 38d47m01s.28
  • Class: A0V (bluish white main sequence star)
  • Magnitude: 0.03
  • Mass: 2.1 times the sun
  • Distance: 25 light years


What is Star Vega

The name Wega comes from the Arabic name al-nasr al-waqi , which means “The diving eagle.” It was already known to the Egyptians and symbolized the other stars of the Lier a vulture. In 1851 it was the first star to be photographed other than the Sun. This was revolutionary because photography was still in its infancy at the time and the photographic plates were too insensitive to photograph small point sources like stars. From here, photography was gradually introduced into astronomy. Wega was also the first star in a spectrum to be photographed. This led to the concept of magnitude and it was anchored in the fact that Wega was at exactly zero magnitude at all wavelengths. It was the ester that is still used to tune telescopes, calibrate instruments, and cameras for testing. Meanwhile, the definition of the concept of magnitude ha changed and the zero point is now in front of a specific intensity of light (also called flux). In visible light Wega is not far from three hundredths of a magnitude.

The age, color and the distance of Star Vega

Wega is a bluish-white, main sequence star with quiet burning hydrogen. With an age of 400 million years, it is about halfway through its life-cycle. It is hotter, heavier and about 36 times stronger than the Sun. The diameter is more difficult to calculate. Wega is a star that rapidly rotates on its axis, the centrifugal forces cause the star to be  considerably flattened at the poles. Finding a good measurement is even more difficult due to the fact that we look right up against one of the poles of the star from the Earth. The currently recorded diameters are 2.36 times larger than the Sun from pole to pole, and 2.82 times at the equator.

Wega’s dust disk: are there planets?

In 1983, Wega was exammined by the Infrared Astronomical Satellite (IRAS). And it was discovered that above-normal levels of infrared light were being emitted. These levels surpassed that of some hotter stars like Vega. Further investigation revealed that this light was not coming from the star itself, but from a band around it. This led to the conclusion that Vega was surrounded by a disc of material that was about 80 times the distance between the Sun and the Earth. The Spitzer Space Telescope was used to photograph the disk dust in 2005. It was concluded that its total mass was about 0.3% of the Earth’s and further development of planets would not be possible. But this does not eliminate the possibility that there are other planets around Vega. They may be too small to be found with our current instruments.

Star Vega: North Star of the past, North Star of the Future

Wega, due to the precession of the Earth over a twelve thousand years ago, is the site of the North Star ingest. The last time it was a pole star was about fourteen thousand years ago during the ice ages. It is the brightest star in the sky; north or south, that may be a pole star . However; that will change as the stars continue to move. Slowly but surely Wega will move closer to the Sun. In the future it could be brightest star in our sky on the horizon. This will probably last for a few hundred thousand years.