Size comparison: Sun vs Vega

Size comparison between the two stars, Vega and the Sun.

Vega is the brightest star in the constellation of Lyra. It is the fifth brightest star in the night sky. It is the star that has been most studied by astronomers; it is considered to be the most important star in the sky, after the Sun. Its lifetime should be ten times shorter than the life expectancy of the Sun, because of its mass which is twice that of the Sun.

Its white color which tends towards blue comes from the fact that the hydrogen present in its core is being transformed into helium thanks to nuclear fusion. It will become a red giant in 550 million years, then a white dwarf.

Vega is said to have a debris disk similar to the Kuiper Belt. A gas giant planet would revolve around Vega.

Poor metallicity:

This star has very few elements that are heavier than helium. Indeed, its metallicity is unusually low. Its abundance in metals is only 32% of that of the Sun. By comparison, Sirius has a metallic abundance that is 3 times greater than that of the Sun. This anomaly is normally only noticeable when the star has finished burning its hydrogen. It is assumed that the environment of the star during its formation was poor in metals.

North Star :

It was the pole star in the north 12,000 years before Jesus Christ and will be again in 11,700 years. In 210,000 years, Vega will be the brightest star in the sky and will remain so for a period of 270,000 years.

Object	Sun	Vega
Type	Star, yellow dwarf	Star, white giant tinged with blue
Age	4.6 billion years	455 million years
Diameter	1,392,684 km	3,911,000 km
Mean radius	696,342 km	1,955,000 km
Mass	1.98 × 1030 kg	4.21 × 1030 kg
Rotation duration	24 days	16.5 hours
Surface gravity	274.4 m/s²	125.89 m/s²
Circumference	4.3 million km	12.2 million km
Surface area	6.09 × 1012 km2	48 × 1012 km2
Volume	1.41 × 1018 km3	3.12 × 1019 km3
Number of planets	8	1
Sun distance	0 km	25.04 light years
Luminosity	3.82 × 1026 W	1.53 × 1028 W
Photosphere temperature	5,772 K	9,602 K
Distance from the Milky Way center	27,200 light years	-
Spectral classification	G2V	A0Va
Absolute magnitude	4.83	0.58
Right ascension	19h 4m 30s	18h 36m 56,33635s
Declination	+63.87°	+38° 47′ 01,2802″

Note: if one of the objects is not visible, it just means that it is too tiny to be displayed compared to the other one.