The relationship between a main sequence star's b-v color value and luminosity is a direct relationship.
The Hipparcos satellite measures the distances between hundreds of thousands of stars. It measures the magnitude of each stars through two filters which are, a blue filter, yielding for B magnitude (for blue) and a greenish filter, yielding a V magnitude (for visual).
The difference between the B and V magnitude of star is (B-V) color , or sometimes just "color" in short. The wavelength of light where the star is related to the star's temperature, i.e., the hotter the star the more blue it is and the cooler the star the more red it is.
To learn more about Hipparcos satellite click here:
brainly.com/question/24198240
#SPJ4
North-east Africa is where you would find it
When the vice-president is absent, the person who is the head of the senate is called
president pro tempore
Right now, it's Orrin Hatch, and generally the most senior senator (by length of service) is chosen for this position
The cause is when North Korea, supported by the Soviet Union and China, invaded South Korea
Answer:
The land that was given by the king to a noble was called a fief.