In: Physics
The motion of the Alpha Centauri system has a radial component of 20 km/s towards the Sun. What
is the measured Doppler shift in the spectral lines? (give your answer as a percentage of the speed
of sound either towards the blue or the red). With a measured proper motion of 3.7 arcsec/year (or
3.7”/yr) at a distance of 1.3 pc, what is the true space motion velocity of the Alpha Centauri system?
Pick Alpha Centauri A, from a HR diagram, read of the temperature and luminosity. With this,
calculate its radius. Haw can you estimate its mass and why? With the mass, how long did it take for
this star to arrive at the main sequence? How long will it stay in the main sequence? What is its fate?