Size comparison: Arcturus vs Sun

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

Arcturus lies in the Spring Triangle asterism. This star is visible in the sky following the extension of the tail of the Big Dipper. It is one of the fastest moving stars in space. From this unusual speed, it is assumed to be part of an ancient small galaxy that merged with the Milky Way. His name means guardian of bears.

Object	Arcturus	Sun
Type	Star, red giant	Star, yellow dwarf
Age	7.1 billion years	4.6 billion years
Diameter	35,374,170 km	1,392,684 km
Mean radius	17,687,080 km	696,342 km
Mass	2.13 × 1030 kg	1.98 × 1030 kg
Surface gravity	0.46 m/s²	274.4 m/s²
Circumference	111.1 million km	4.3 million km
Surface area	3.93 × 1015 km2	6.09 × 1012 km2
Volume	2.31 × 1022 km3	1.41 × 1018 km3
Average orbital speed	122 km/s	1.99 km/s
Sun distance	36.7 light years	0 km
Luminosity	6.49 × 1028 W	3.82 × 1026 W
Photosphere temperature	4,286 K	5,772 K
Distance from the Milky Way center	-	27,200 light years
Spectral classification	K1.5 IIIFe-0.5	G2V
Absolute magnitude	-0.31	4.83
Right ascension	14h 15m 39,67s	19h 4m 30s
Declination	+19° 10′ 56,67″	+63.87°

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.