Luminosity classes of stars are designated by Roman numerals and tell us what region of the H-R diagram the star falls in. We use both spectral type and luminosity class to completely classify stars; the spectral type tells us the star's temperature while the luminosity class tells us its radius.Luminosity classes of stars are designated by Roman numerals and tell us what region of the H-R diagram the star falls in. We use both spectral type and luminosity class to completely classify stars; the spectral type tells us the star's temperature while the luminosity class tells us its radius.
What does the luminosity of a main sequence star tell us?
Main sequence is when a star is burning hydrogen in its core. The luminosity and temperature of a main-sequence star are set by its mass. More massive means brighter and hotter. A ten solar mass star has about ten times the sun's supply of nuclear energy.
What is the luminosity class of a main sequence star quizlet?
Luminosity class I represents supergiants, III represents giants, and V represents main-sequence stars; luminosity classes II and IV are intermediate to the others. The length of time for which a star of a particular mass can shine by fusing hydrogen into helium in its core.
What is meant by the luminosity of a star quizlet?
luminosity- The luminosity of a star is the amount of light it emits from its surface. apparent brightness-how bright the star appears to a detector here on Earth. The difference between luminosity and apparent brightness depends on distance.
What does the luminosity of a star tell us about its lifespan?
A star's mass gives a measure of the amount of "fuel", and its luminosity gives a measure of the rate at which this "fuel" is consumed by nuclear burning, so a star's lifetime is proportional to its Mass divided by its Luminosity.
What is luminosity of a star?
Astronomers also measure luminosity — the amount of energy (light) that a star emits from its surface. Measuring star brightness is an ancient idea, but today astronomers use more precise tools to obtain the calculation.
What does the luminosity class of a star tells an astronomer?
Luminosity classes of stars are designated by Roman numerals and tell us what region of the H-R diagram the star falls in. The spectral type tells us the stars temperature while the luminosity class tells us its radius.
WHAT IS A stars luminosity class related to?
In the MK system, a luminosity class is added to the spectral class using Roman numerals. This is based on the width of certain absorption lines in the star's spectrum, which vary with the density of the atmosphere and so distinguish giant stars from dwarfs.
What is luminosity quizlet?
Luminosity: the amount of energy radiated per second by a star. Brightness: how bright a star appears to the naked eye.
What is a star’s luminosity?
Astronomers also measure luminosity — the amount of energy (light) that a star emits from its surface. Measuring star brightness is an ancient idea, but today astronomers use more precise tools to obtain the calculation.