The brightest star as seen from Earth is the sun. The brightest star in the night sky is Sirius.
At its brightest its apparent magnitude is 13.65.
Apparent magnitude is the measure of how bright a star appears as seen from Earth. This scale is based on a star's brightness perceived by human observers. The lower the apparent magnitude, the brighter the star appears.
The numeric value of the apparent magnitude would increase, since bright objects have lower magnitude values than dim objects.To give some actual numbers as an example: the Sun has an apparent magnitude of about -27. It is much, much brighter than the moon, which at its brightest has an apparent magnitude of -13 or so.
"First magnitude" usually means the brightest 21 stars, as seen from Earth. Another definition is stars with apparent magnitudes 0.5 to 1.5. This definition excludes the very brightest stars, like Sirius. They are the first stars that become visible after sunset and they all have names. Examples are Altair, Aldebaran, Capella, Spica, Antares, Fomalhaut, Deneb, Regulus, Sirius, etc. There can be confusion because First Magnitude stars are not stars with an "apparent magnitude" of exactly "one". They are just the brightest stars, but naturally their magnitudes are close to one.
The apparent brightness of a star is represented by its apparent magnitude, which is a logarithmic scale used to measure the brightness of celestial objects as seen from Earth. The lower the apparent magnitude number, the brighter the star appears in the sky. Each increase of one magnitude corresponds to a brightness factor of 2.5.
At its brightest its apparent magnitude is 13.65.
Apparent magnitude is the measure of how bright a star appears as seen from Earth. This scale is based on a star's brightness perceived by human observers. The lower the apparent magnitude, the brighter the star appears.
Apparent
The Sun (Sol) has an apparent magnitude of - 26.74Siruis (Dog star) with an apparent magnitude of -1.47 (Brightest in the Northern Hemisphere)Canopus with an apparent magnitude of -0.72 (Brightest in the Southern Hemisphere)Arcturus with an apparent magnitude of -0.04 (Variable)Alpha Centauri A with an apparent magnitude of -0.01Vega with an apparent magnitude of 0.03Rigel with apparent magnitude of 0.18Procyon with apparent magnitude of 0.34Achernar with apparent magnitude of 0.50Betelgeuse with apparent magnitude of 0.58 (Variable)A lower number means more brightness. All of these are apparent magnitudes. If you mean intrinsic magnitude, the answers are somewhat different. Sirius and Alpha Centauri A are bright because they're close to us. Canopus, on the other hand, is much brighter, but also much further away (Sirius is about 8 light years away; Canopus is more than 300 light years away).Off subject:Some planets are brighter (in apparent magnitude) than stars; for example, when Venus appears in the sky, she is always the brightest object (after the Sun and the Moon). In fact, Venus is bright enough to be seen in the broad daylight, if you know where to look. Planets look like stars, but their movement between the stars can be detected if you observe them just for a few nights.
The numeric value of the apparent magnitude would increase, since bright objects have lower magnitude values than dim objects.To give some actual numbers as an example: the Sun has an apparent magnitude of about -27. It is much, much brighter than the moon, which at its brightest has an apparent magnitude of -13 or so.
This is called "Apparent Magnitude".
Capella (Alpha Aurigae) is the brightest star in the constellation Auriga.Although it appears as a single star, it is in fact a pair of binary stars. The primary pair are listed here.Capella A - Absolute magnitude: +0.35Capella B - Absolute magnitude: +0.20Capella A - Apparent magnitude: +0.91Capella B - Apparent magnitude: +0.76See related question for the difference.
Anything that is not the measure of intrinsic brightness of a celestial object.
"First magnitude" usually means the brightest 21 stars, as seen from Earth. Another definition is stars with apparent magnitudes 0.5 to 1.5. This definition excludes the very brightest stars, like Sirius. They are the first stars that become visible after sunset and they all have names. Examples are Altair, Aldebaran, Capella, Spica, Antares, Fomalhaut, Deneb, Regulus, Sirius, etc. There can be confusion because First Magnitude stars are not stars with an "apparent magnitude" of exactly "one". They are just the brightest stars, but naturally their magnitudes are close to one.
The brightness as seen from Earth is called the "apparent magnitude".The real brightness (defined as the apparent brightness, as seen from a standard distance) is called the "absolute magnitude".
The apparent magnitude of the Sun is -26.73. (Yes negative)The absolute magnitude of the Sun is 4.83See related question for the difference between absolute and apparent magnitude.For comparison at maximum brightness.Full Moon -12.6Venus -3.8Mars - 3Sirius -1.47Ganymede 4.6Object visible with the naked eye 6.5
Apparent magnitude is the brightness of a celestial object as seen from Earth, taking into account distance and extinction from the atmosphere. Absolute magnitude measures the intrinsic brightness of a celestial object if it were placed at a standard distance of 10 parsecs (about 32.6 light-years) away from Earth. In essence, apparent magnitude is how bright an object appears from Earth, while absolute magnitude is how bright it would be at a standardized distance.