Absolute magnitude. Two stars of the same absolute magnitude usually do not have the same apparent magnitude because one may be much farther from us than the other. The other that is farther away will appear dimmer. To compare absolute brightness, astronomers determine what magnitude the stars would have if they were at a standard distance of about 32.6 light years. The sun has an apparent magnitude of -26.7, if located at a distance of 32.6 light years, have an absolute magnitude of 5. Stars with absolute magnitude values lower than 5 are brighter than the sun. Because of their distance, however, they appear much dimmer.
A lot brighter than you think actually.
This is a large subject. [We know of no other larger!]
Briefly, once it was hypothesized that all stars were equally bright, and that their apparent brightness was due to their distance from us. These studies soon led to classifications of stars that shared similar characteristics; colour, brightness, etc; and this led to a broader understanding of a better model.
In particular, a group of stars that periodically varied in brightness, the Cepheid variables, were discovered, and in this group there was a definite correlation between their brightness and their variability. This gave us a 'standard candle' for measuring the distance of stars, and from the resultant data, Hubble and others conceived the idea of an expanding universe, which in more recent times has led to the Big Bang theory for the origin of the Universe some 14 billion years ago.
Of course, many of what we think of as stars, are in fact complete Galaxies in their own right. There have been many attempts to classify the stars and galaxies.
Technically the Sun is a star - so the Sun.
The brightest star seen from Earth is Sirius A (alpha Canis Majoris), located 8.64 light-years from Earth, is the brightest star in the night sky, with an apparent magnitude of -1.46 million miles (2.33 million km), a mass 2.14 times that of the Sun, and is visually 24 times brighter than the sun.
Commonly called "magnitude" but more accurate is "apparent magnitude" because a very bright object could be so far away it is difficult to see it.
That's called the star's "apparent magnitude".
The apparent magnitude.
Apparent Magnitude
Star brightness is defined in terms of apparent magnitude, which is how bright the star appears from Earth. Star brightness is also defined by absolute magnitude, which is how bright a star appears at the standard distance of 36.2 light years. Luminosity is also a way that a star's light is measured.
there are two separate ways that astronomers measure the brightness of a start, there is actuall and aparent brightness. In apparent brightness, the measure how bright it looks to all the humans on Earth. However, the actual brightness of a star is different. Say a star is really, really bright, but really far away. That star would look preety dim. Or if a star is not so bright, but really close, like the Sun. The actuall brightness of a star is harder to measure, but is possible by use of waves and stuff like that, I don't know too much about actuall brightness
It is called Vmag. This is the visual magnitude of the object. Visual magnitude is a scale used by astronomers to measure the brightness of a star or other celestial object. Visual magnitude measures only the visible light from the object. The lower the V-MAG the brighter the star. You can go to http://seasky.org/pictures/sky7b14.html to learn more.
Absolute Brightness .
Scientists actually use two measurements to identify a star's brightness. One is luminosity, or the energy that star puts out. Another is magnitude, or the amount of light a star puts out.
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".
Absolute Brightness: How bright a star appears at a certain distance. Apparent Brightness: The brightness of a star as seen from Earth.
Distance from Earth, size of star, and temperature of star.
Distance from Earth, size of star, and temperature of star.
A variable star is a star whose brightness as seen from Earth that fluctuates.
A variable star is a star whose brightness as seen from Earth that fluctuates.
A variable star is a star whose brightness as seen from Earth that fluctuates.
Three factors that affect a star's brightness are the star's distance from earth, its age and its luminosity. The farther the star is from earth, the less bright it appears. As a star increases in age, its brightness also increases. Its brightness also depends on its luminosity, which is the amount of energy the star emits per second.
No - a star as seen from earth is it's apparentbrightness. It's absolute brightness is measured by astronomical instruments. The brightest visible star from earth is Sirius, in the constellation Canis Major. Spica, in Virgo, has a much higher absolute brightness than Sirius, but Sirius is much closer to earth, so it is apparently brighter than Spica.
it is doubble the brightness
The measure of a star's brightness is its magnitude. A star's brightness as it appears from Earth is called its Apparent Magnitude.Star's brightness is measured by there magnitude.
Delta Scuti is a giant star. It is part of the Scutum constellation. It is also known as a variable star because its brightness as seen from earth fluctuates.