A measure of the amount of light received on Earth is a star's?

Answer 1

we cannot measure the brightness directly. The light reaching the earth is studied and measured. It is again not measured by energy measuring instrument. The magnitude of the light reaching the earth is measured by a scale proably called apparent magnitude.

also known as "stellate magnitude" (Times 898 - 49 across)

Answer 2

Apparent Magnitude

It is a scale where each successive integer is half as bright as the one below it (-3 is twice as bright as -2, etc). For example, Venus is around mag -4, and the human eye can see object up to mag 7

Answer 3

because a star's atmosphere absorbs colors of instead of emitting them, the spectrum of a star is called an absorption spectrum. an absorption spectrum is produced when light from a hot solid or dense gas passes through a less dense, cooler gas. The cooler gas absorbs certain portions of the spectrum.therefore, the black lines of a star's spectrum represent portions of the spectrum that are absorbed by the atmosphere.

Answer 4

The apparent brightness is how much energy is coming from the star per square meter per second, as measured on Earth. The units are watts per square meter (W/m2)

Also see the related question below.

Answer 5

Astronomers measure how bright stars are by: First, determining the flux from the star (the rate at which energy reaches us from the star per unit area). This can be done using a CCD camera quite easily. Then, as one knows the distance to the star, one can determine how luminous the star should be to give the required flux.

Answer 6

The energy content of radiant energy such as sunlight is typically measured in watts per square meter.

Answer 7

One measure of light received from the sun is 4k/3 watts/meter squared, the solar constant.

Answer 8

It is called absolute luminosity or magnitude

Answer 9

apparent magnitude

Answer 10

Absolute magnitude.