Because the peak of their blackbody curve is near blue in the spectrum, for the temperature of their photosphere.
Alpheratz is a hot blue-white star. Its color can appear white to the naked eye, but closer inspection with a telescope may reveal a slight blue tint.
If the star is a bright blue-whit color then the star is hot....but if its red, or a color that's close top red then the it isn't hot, but its not cold either....its just not as hot as the blue-white star is. You can also find this information and more in the Kelvin Scale below.
A star's color indicates its temperature. Hotter stars emit more blue light and appear blue or white, while cooler stars emit more red light and appear red or orange. By studying a star's color, astronomers can determine its temperature and infer other properties like its age and size.
The color of a star is its . . . color. In other words, a star's color shows us how white-hot it is. Some stars, like our Sun, are colored slightly in the yellow direction of white-hot. Bigger stars are less yellow and more blue - the bigger, the hotter, the bluer shade of white-hot they are. Red giants, white dwarfs and black holes are something related, but different.
A blue star is a type of star that is hot, massive, and emits predominantly blue light. These stars have temperatures of around 10,000 to 40,000 degrees Celsius, causing them to appear blue in color. Blue stars are typically young and have short lifespans compared to other types of stars.
The hottest stars are blue or blue-white, the coldest stars are red. In between, from colder to hotter are orange and yellow and maybe green. A white dwarf star is even hotter than a blue-white star, but it is dead and no longer undergoing fusion.
A medium hot star typically appears white or blue in color. The color of a star is determined by its surface temperature, with hotter stars emitting more blue light compared to cooler stars which emit more red light.
It relates to how hot it is because if it was blue it would be a hotstar and it it was red it would be a cool star!
The color of a star is related to its temperature - hotter stars appear blue or white, while cooler stars appear red. This is because the temperature of a star affects the distribution of light it emits, with hotter stars emitting more blue light and cooler stars emitting more red light. The color of a star can therefore be used to estimate its temperature.
The temperature of a star is correlated with its color. Hotter stars appear blue or white, while cooler stars appear red or orange. This relationship is governed by a star's surface temperature, with cooler stars emitting longer, redder wavelengths and hotter stars emitting shorter, bluer wavelengths.
Beta Leonis (or Denebola) is the second brightest star in the constellation Leo. It is a type A3V star. This means it is very hot 7,500 -> 10,000 Kelvin and will appear as white.
Star colors tell us how hot the star is. For example a red colored star is cool and a blue colored star is hot.