sirus is the brightest star in the night sky idk how far away it is maby like 100 thousand light years
A star's brightness at a standard distance is referred to as its apparent magnitude. This standard distance is 10 parsecs (32.6 light-years) from Earth. Apparent magnitude allows astronomers to compare the brightness of stars as seen from Earth, regardless of their actual distance from us.
Absolute Brightness .
Edwin Hubble measured the distance to the Andromeda Galaxy using Cepheid variable stars as standard candles. By observing how the brightness of these stars changed over time, he could determine their true brightness and then calculate their distance based on their apparent brightness. This allowed him to estimate the vast distance to the Andromeda Galaxy.
The idea is that CERTAIN TYPES of stars, including certain variable stars (such as Cepheids) have a known brightness; so if you observe their apparent brightness, you can calculate their distance.
by temperature, size, brightness, distance and color
midorz
A "standard candle" in astronomy is an object whose luminosity (its true brightness, not just how bright it seems to us) can be estimated, based on characteristics of that type of object. Then its distance can be estimated from its "apparent magnitude". The stars called "Cepheid variables" are a good example. The rate at which their brightness varies is closely linked to their luminosity.
The surface temperature and the absolute magnitude, which is the brightness of the star when viewed from a standard distance of 10 parsecs.
That is called "absolute brightness" or "absolute magnitude". It is defined as how bright a star would look at a standard distance (10 parsec, to be precise). The brightness of stars can vary a lot; some stars (supergiants) are millions of times as bright as our Sun, others (red dwarves) are thousands of times less bright. (Our Sun is in the top 10 percentile, though.)
"Apparent magnitude" is the star's brightness after the effects of distance. "Absolute magnitude" is the star's brightness at a standard distance.
The intrinsic brightness of a star is called its absolute magnitude. This is a measure of how bright a star would appear if it were located at a standard distance of 10 parsecs (32.6 light-years) from Earth.
No. The stars are not only not the same brightness, they are not the same distance from us - they just "appear" to be as part of the optical illusion of earthbound astronomy. They are all of varying brightness, though fairly close in brightness overall.