However, the brightness of a star depends on its composition and how far it is from the planet. Astronomers define star brightness in terms of apparent magnitude — how bright the star appears from Earth — and absolute magnitude — how bright the star appears at a standard distance of 32.6 light-years, or 10 parsecs.

The scale for absolute magnitude is the same as that for apparent magnitude, that is a difference of 1 magnitude = 2.512 times difference in brightness. This logarithmic scale is also open-ended and unitless. Again, the lower or more negative the value of M, the brighter the star is.

Absolute magnitude is defined to be the apparent magnitude an object would have if it were located at a distance of 10 parsecs. So for example, the apparent magnitude of the Sun is -26.7 and is the brightest celestial object we can see from Earth.

1 Answer. Luminosity is the total energy output of a star per unit time. The absolute magnitude is, in some ways, analogous to luminosity in that it is a measure of the energy output of a star. The definition of absolute magnitude is that it is the magnitude a star would have if it were 10 parsecs from an observer.

Flame colorants

The hottest flame is violet on the color spectrum and white in the visible spectrum. The type of fuel and impurities, in addition to the flame temperature, contribute to the color of the flame.

Green flame can be caused by copper salts or corroded copper parts contaminating the flame with copper ions. However if someone intentionally put larger amount of toxic copper salts there, that might be dangerous. There are further metals and even organic compounds that tint the flame green or burn with green flame.

Any boron-containing compound will cause flames to emit a green colour. When boron compounds are heated, electrons absorb a certain amount of heat energy that causes them to jump to higher energy levels. Because the energy absorbed by electrons is different per element, each element will give a different colour.

Blue flames have more oxygen and get hotter because gases burn hotter than organic materials, such as wood. For example, the element lithium will produce a pink flame, while the element tungsten will produce a green flame.

Colors of Other Elements

Certain elements gives off a characteristic colour when heated to high temperature. The heat of the flame excites the metal ions, causing them to emit visible light. Explanation: The emission spectra of barium contains the wavelenght corresponding to green colour, hence barium gives green colour.