25 Facts About Vega

1.

Vega is the brightest star in the northern constellation of Lyra.

FactSnippet No. 1,335,131
2.

Vega has been extensively studied by astronomers, leading it to be termed "arguably the next most important star in the sky after the Sun".

FactSnippet No. 1,335,132
3.

Vega was the first star other than the Sun to have its image and spectrum photographed.

FactSnippet No. 1,335,133
4.

Vega has functioned as the baseline for calibrating the photometric brightness scale and was one of the stars used to define the zero point for the UBV photometric system.

FactSnippet No. 1,335,134
5.

Vega is only about a tenth of the age of the Sun, but since it is 2.

FactSnippet No. 1,335,135
6.

Vega is a variable star that varies slightly in brightness.

FactSnippet No. 1,335,136
7.

From Earth, Vega is observed from the direction of one of these poles.

FactSnippet No. 1,335,137
8.

At latitudes to the north of 51° N, Vega remains continuously above the horizon as a circumpolar star.

FactSnippet No. 1,335,138
9.

Vega is the brightest of the successive northern pole stars.

FactSnippet No. 1,335,139
10.

On 17 July 1850, Vega became the first star to be photographed, when it was imaged by William Bond and John Adams Whipple at the Harvard College Observatory, with a daguerreotype.

FactSnippet No. 1,335,140
11.

Distance to Vega can be determined by measuring its parallax shift against the background stars as the Earth orbits the Sun.

FactSnippet No. 1,335,141
12.

Vega is one of six A0V stars that were used to set the initial mean values for this photometric system when it was introduced in the 1950s.

FactSnippet No. 1,335,142
13.

The magnitude of Vega was measured again in 1981 at the David Dunlap Observatory and showed some slight variability.

FactSnippet No. 1,335,143
14.

Vega became the first solitary main-sequence star beyond the Sun known to be an X-ray emitter when in 1979 it was observed from an imaging X-ray telescope launched on an Aerobee 350 from the White Sands Missile Range.

FactSnippet No. 1,335,144
15.

In 1983, Vega became the first star found to have a disk of dust.

FactSnippet No. 1,335,145
16.

At present, Vega has more than twice the mass of the Sun and its bolometric luminosity is about 40 times the Sun's.

FactSnippet No. 1,335,146
17.

Energy flux from Vega has been precisely measured against standard light sources.

FactSnippet No. 1,335,147
18.

The visual spectrum of Vega is dominated by absorption lines of hydrogen; specifically by the hydrogen Balmer series with the electron at the n=2 principal quantum number.

FactSnippet No. 1,335,148
19.

The X-ray emission from Vega is very low, demonstrating that the corona for this star must be very weak or non-existent.

FactSnippet No. 1,335,149
20.

However, this discrepancy can be explained if Vega is a rapidly rotating star that is being viewed from the direction of its pole of rotation.

FactSnippet No. 1,335,150
21.

Radial velocity of Vega is the component of this star's motion along the line-of-sight to the Earth.

FactSnippet No. 1,335,151
22.

Models fitted to the dust distribution around Vega indicate that it is a 120-astronomical-unit-radius circular disk viewed from nearly pole-on.

FactSnippet No. 1,335,152
23.

The disk of dust is produced as radiation pressure from Vega pushes debris from collisions of larger objects outward.

FactSnippet No. 1,335,153
24.

The inclination of planetary orbits around Vega is likely to be closely aligned to the equatorial plane of this star.

FactSnippet No. 1,335,154
25.

In Zoroastrianism, Vega was sometimes associated with Vanant, a minor divinity whose name means "conqueror".

FactSnippet No. 1,335,155