Around the Sky in 28 Days – Day 24

The Moon rises early in the morning. This morning it will be in line with 3 of the brightest stars in the winter Milky Way; the Gemini twin stars of Castor and Pollux and Procyon, the brightest star in the ‘little dog’ Canis Minor.

Pollux
magnitude +1.2
brightest star in constellation of Gemini
17th brightest star in sky
K0 type orange giant star
younger but more evolved than Sun
1.7 solar masses
8.8 solar diameters
32 times brighter than Sun
may have an 2 Jupiter mass planet
33.7 lightyears from Earth (198,105,444,000,000 miles away)

Castor
magnitude +1.9
2nd brightest star in constellation of Gemini
44th brightest star in sky
sextuplet star system (made up of 3 very close pairs)
biggest star has 2.2 solar masses, 2.3 solar diameters
biggest star is 30 times brighter than the Sun
51.6 lightyears from Earth (303,337,308,000,000 miles away)

Procyon
magnitude +0.3
Brightest star in constellation of Canis Minor
7th brightest star in the sky
spectral type of F5
binary star system (white dwarf secondary of 0.6 solar masses)
biggest star has 2.1 solar masses, 1.4 solar diameters
biggest star is 7.7 times brighter than the Sun
11.4 lightyears from Earth (67,000,000,000,000 miles away)

Tomorrow – Day 25 – Among a swarm of bees …

About Carl Hergenrother
I am a professional astronomer specializing in the study of comets, asteroids and meteors. This blog will focus on my professional and amateur work in this field

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