How would you classify the sun based on the characteristics that astronomers use to identify a star's brightness temperature and size?

Answer 1

Sol (our sun) is a yellow-orange, medium-sized star. Of course, we use our own star as a reference by which to judge other stars, so Sol is considered the baseline on all of the scales. The diagram by which astronomers judge a star's characteristics is called the Hertzsprung-Russell diagram. Sol is considered a Main Sequence star on this diagram.

Answer 2

Our star, the Sun, is classified as a G2V star, meaning that it has a surface temperature of about 5780 K (5510 °C or 9950 °F)* and its spectral emissions are almost exclusively from fusing hydrogen to helium. Since most of the stellar population is now thought to consist of red dwarf stars, the Sun's size and brightness would be among the top 15% of all stars. But there are many observed stars with size, mass, and brightness greater than the Sun's. The characteristics of stars are often expressed relative to the Sun.

*The temperatures inside the Sun vary by depth but are much hotter, in millions of degrees Celsius.

Answer 3

The HK system (revised from the Harvard system that simply accounts for an extra category based on the mass of stars i.e. giants, main sequence, etc) is a spectral classification system used for stars of varing luminosity, brightness and temperature. From highest to lowest, the classification spectral scheme includes the following types:

O (blue), B (blue-white), A (white), F (yellow white), G (yellow), K (orange) & M (red.) L class has also been recently designated, but this class is for low mass stars such as brown dwarfs, and isn't often mentioned when referring to the spectral types of stars. This system can be memorised by the statement 'Oh Be A Fine Girl Kiss Me'

Wavelengths are also smaller for light (higher packets of photonic energy) for younger stars (i.e. O stars) as opposed to older, cooler and less luminous M type stars. This is because Hydrogen and Helium are more prevalant in younger stars, and are perfect for the process of fusion (i.e. the atoms are the lightest and can be moved more quickly in hot temperatures to collide, fuse, and create bigger Helium atoms, this fusing process also creates additional energy.)

Answer 4

Originally - about 2000 years ago, in ancient Greek - the brightest stars were given a magnitude rating of 1, the least bright stars were given a magnitude rating of 6.

Later this system was formalized with a more exact definition. Also, the brightness scale was extended to negative magnitudes (like Venus, around -4, or the Sun, around -27), to stars or other objects weaker than magnitude 6 (which can be observed only in telescopes), and to fractional magnitudes.

Specifically, if two objects have a difference of 5 in magnitude, the brighter object is 100 times brighter than the weaker one; as a result, 1 magnitude difference is a factor of about 2.5 (fifth root of 100, to be precise).

The above refers to the apparent magnitude, i.e., as seen from Earth; an absolute magnitude can also be defined, i.e., how bright would a star or galaxy seem if it were at a standard distance? - The standard distance varies, depending on whether you want to compare planets, stars, etc. For stars, a distance of 10 parsecs is used as a standard.

Answer 5

The sun is considered a main sequence star on the Hertzsprung-Russell diagram.

Answer 6

See Hertzsprung Russel diagram of solar masses verses temperature and lifetimes. Our Sun is on the 'main sequence'