The total mass of the pair of stars in spectroscopic binaries are difficult to estimate because
a. we can't measure the radial velocities of each star in the system.
b. we can't see the shape or tilt of the orbit.
c. we can't find the diameters of the stars.
d. we can't determine the luminosities of the stars.
e. the Doppler shift is not measurable.
Question 2
The optical shape of segmented mirrors is controlled by computer-driven thrusters under the mirrors in what is called
a. an achromatic lens.
b. active optics.
c. a Schmidt-Cassegrain design.
d. a Newtonian design.
e. interferometry.
Acromegaly in one individual from a pair of identical twins.
Rising and Setting of Stars at Middle North Latitudes
Classifying the Spectra of Stars
Dred Scott and his wife and children are featured on the cover of Frank Leslie’s Illustrated Newspap
Air Mass Thunderstorms
Atomic Number and Mass Number