Velocidad-es una cantidad vectorial física; Tanto la magnitud como la dirección son necesarias para definirlo.
I do believe all of these but core elements can be determined by spectroscopy which includes the use of electromagnetic radiation. Both the surface and core temperature can be measured using light. Surface elements can be found because the absorption lines of different elements in the spectra of the star, but I haven't heard anything about using spectral analysis for core elements.
Answer:
The measured redshift is z =2
Explanation:
Since the object is traveling near light speed, since v/c = 0.8, then we have to use a redshift formula for relativistic speeds.
![z= \sqrt{\cfrac{c+v}{c-v}}-1](https://tex.z-dn.net/?f=z%3D%20%5Csqrt%7B%5Ccfrac%7Bc%2Bv%7D%7Bc-v%7D%7D-1)
Finding the redshift.
We can prepare the formula by dividing by lightspeed inside the square root to both numerator and denominator to get
![z= \sqrt{\cfrac{1+\cfrac vc}{1-\cfrac vc}}-1](https://tex.z-dn.net/?f=z%3D%20%5Csqrt%7B%5Ccfrac%7B1%2B%5Ccfrac%20vc%7D%7B1-%5Ccfrac%20vc%7D%7D-1)
Replacing the given information
![z= \sqrt{\cfrac{1+0.8}{1-0.8}}-1](https://tex.z-dn.net/?f=z%3D%20%5Csqrt%7B%5Ccfrac%7B1%2B0.8%7D%7B1-0.8%7D%7D-1)
![z= \sqrt{\cfrac{1.8}{0.2}}-1\\z= \sqrt{9}}-1\\z=3-1\\z=2](https://tex.z-dn.net/?f=z%3D%20%5Csqrt%7B%5Ccfrac%7B1.8%7D%7B0.2%7D%7D-1%5C%5Cz%3D%20%5Csqrt%7B9%7D%7D-1%5C%5Cz%3D3-1%5C%5Cz%3D2)
Thus the measured redshift is z = 2.