Kelvin and Celcius - when you are talking about stars...

[EnsignParis]

Does it honestly matter if a scientist says that a star is 10000 degrees Kelvin or 10000 degrees Celcius? Honestly, can we measure the temperature of something millions of lightyears away to it's exact temperature within a range of about 270 degrees C?

[Tsuki no Hikari]

When speaking scientifically, Celius isn't used anyway. Everything's preferred to be in Kelvin. That way we get a clear, precise temperature.

Also, when speaking of stars, it's more like 1,000,000 Kelvin and more. That is, for the inner layers, flares, and possibly the corona.

[Oliver]

In total, there are five different temperature scales: the Celsius, the Fahrenheit, the Kelvin, the Rankine and the R�aumur.

The Celsius temperature scale is still sometimes referred to as the "centigrade" scale. Centigrade means "consisting of or divided into 100 degrees." The Celsius scale, devised for scientific purposes, has 100 degrees between the freezing point of 0 degrees and boiling point of 100 degrees of pure water at sea level air pressure.

On the Fahrenheit scale, used primarily in the United States, the freezing point of water is 32 degrees and the boiling point is 212 degrees while measured at standard pressure.

Scientists use a third scale for unique measurements, called the absolute or Kelvin scale. This scale was invented by William Thomson, also know as Lord Kelvin, a British scientist who made important discoveries about heat in the 1800's. Scientists have determined that the coldest it can get, in theory, is minus 273.15 degrees Celsius. This temperature has never actually been reached, though scientists have come close. The value, minus 273.15 degrees Celsius, is called absolute zero. At this temperature scientists believe that molecular motion would stop. You can't get any colder than that.

A now somewhat obsolete scale is used in specific calculations and measurements. It was created by R�aumur a French scientist. He knew nothing of Fahrenheit's work and did not use mercury, but did produce a good working thermometer. He used the freezing point of water as his zero mark, and put the boiling point at 80 degrees. This scale was widely used in the 18th and 19th centuries, especially in France, in scientific communities. He has a greater claim to fame for much of the other scientific work he did.

Rankine, a Scottish engineer, created his scale, which was merely the Kelvin scale using the Fahrenheit degree instead of the Celsius. It has also had some wide use in scientific communities but is of no practical use in other areas of measurement.

[webtaz99]

The spectra of stars (and other objects) reveal their temperature. The accuracy of the temperature reading is based on the accuracy of the spectral measurement. Modern spectral measurements are accurate to five or six digits.

[Lt. Commander Warwick]

This may sound like I'm a techer; Oliver, that is a very good answer. Well thought out and told.