Why cant you visit alpha centauri?

Answer 1

Multiple questions.

See related questions.

Answer 2

Brightness can be looked at in two ways. How it seen to us and how bright it really is.

Looking at the Magnitude (comparative brightness) the Sun is the leader. However when people say "star" they often exclude the the Sun because it shines during the "daylight" hours and they mean stars which are visible at night. In that case Sirius is the brightest star in the night sky. On an absolute basis (how bright it is, not how bright it seems in comparison to other stars in the night sky) Cygnus OB2-12 (a very bright blue hypergiant) is the winner. It is more than 6 million times brighter than the Sun, but is 5000 light-years away .

The Sun seems bright to us because it is so close (only 93 million miles away). Sirius is bigger (See Link for comparison of sizes of the sun and other stars) The Sun is called a yellow dwarf to indicate its small size and cool temperature. Sirius is 2.6 parsecs (8.6 light-years) from Earth and twice as massive as the Sun. It is 25 times more luminous than the Sun.

Interestingly Sirius used to have a companion star that was equally as bright but it has now changed to a white dwarf.

Answer 3

Sirius A is 2.02 times the mass of our Sun. Sirius B (a dwarf star) is 0.978 times the mass of our Sun. Data from Wikipedia.

Sirius A is 2.02 times the mass of our Sun. Sirius B (a dwarf star) is 0.978 times the mass of our Sun. Data from Wikipedia.

Sirius A is 2.02 times the mass of our Sun. Sirius B (a dwarf star) is 0.978 times the mass of our Sun. Data from Wikipedia.

Sirius A is 2.02 times the mass of our Sun. Sirius B (a dwarf star) is 0.978 times the mass of our Sun. Data from Wikipedia.

Answer 4

We can. Alpha Centauri is one of the brightest stars in the sky. Because of its position in the sky, however, it is not visible to most of the northern hemisphere. Proxima Centauri is not visible from Earth because it is too dim.

Answer 5

Alpha Centauri is actually a three-star system. Two of the stars, Alpha Centauri B and C are dimmer than the sun while Alpha Centauri A is about 50% brighter. Altogether the system is about twice the luminosity of the sun.

Answer 6

Of the stars within 10 light years, it's the most intrinsically bright.

On the grand scale, it's not particularly noteworthy, but because it's so close, it appears to outshine ... slightly ... real standouts like Rigel and Canopus (which are much further away).

Answer 7

Sirius A is the brightest star in the sky after our sun. Its not the closest star, but is one of the closest. It also has a high luminosity, with a white spectral class and surface temperature of around 10,000 Kelvin. Its a combination of its proximity and its actual brightness that makes it the brightest star when viewed from earth (after the sun). There are closer stars, but most in our neighbourhood are red dwarfs which burn much less brightly.

Answer 8

A combination of it's close distance and it's luminosity. It's one of the closest stars to us at around 8.6 light years (there are actually two stars, Sirius A is the bright one though). There are closer stars to us than this star system, but most of these are dim red dwarfs. Compared with the sun, sirius A is around 25 times brighter (absolute magnitude) and twice as massive. It is a hot, brightly burning white star, with a temperature of around 25,000 kelvin at the surface.

Answer 9

• Sirius has a radius of about 1.711 that of the Sun.
• The Sun has a radius of about 109 that of the Earth.

So 1.711 x 109 gives about 186.5 times larger than the Earth.

Answer 10

Alpha Centauri is a star system containing 3 stars.

• Alpha Centauri A - 1.1 times larger than the Sun
• Alpha Centauri B - 0.907 times smaller than the Sun
• Alpha Centauri C (Proxima centauri) 0.145 times smaller than the Sun