Temperature of a "White Hot"Object

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Chaisson, Eric and McMillan, Steve. Astronomy Today. New Jersey: Prentice-Hall, 1993.

Stellar Colors and Temperatures
B Intensity V Intensity	Surface Temperature (K)	Color	Familiar Examples
1.0	10,000	White	Vega, Sirius
0.8	8,000	Yellow-white	Canopus

8,000–10,000 K

The Audubon Society–Field Guide to the Night Sky. New York: Knopf.

SPECTRA TYPES
Type	Color	Temperature Range (K)	Example
A	Blue-white	11,000–75,000[sic]	Sirius (Alpha Canis majoris)
F	White	6,000–7,500	Procyon (Alpha Canis minoris)
G	Yellow-white	5,000–6,000	The Sun

5,000–11,000 K

Process Associates of America. Metal Temperature by Color. 1995–2000.

Metal Temperature by Color
Color	°F	°C	K
White	2200	1205	1480

1,480 K

Pananides, Nicholas A. and Arny, Thomas. Introductory Astronomy. California: Addison-Wesley, 1979.

Familiar stars in the spectral sequence
STAR	COLOR	SPECTRAL CLASS	TEMPERATURE (K)	COLOR INDEX
Procyon	Blue to white	F5	7,000	0.41
Sun	White to yellow	G2	6,000	0.65
Capella	White to yellow	G8	5,500	0.79

5,500–7,000 K

Gordon, Gary. Light and Color. May, 1987.

COLOR RENDERING INDEX (CRI)
Lamp color name	Apparent color temperature (Kelvin)	Color Rendering Index (R)
Warm white	3000	52
Deluxe warm white	2900	73
White	3500	60
Cool white	4200	66
Deluxe cool white	4200	89
Sign white	5200	86
Daylight	7000	79

3,000–7,000 K

From the previous study of electromagnetic radiation in Physics, we learned that color is related to the frequency (or wavelength) of light. Yet color is also related to temperature. For instance, by observing colors of the stars, we could tell which stars are hotter and which ones are cooler.

Since all objects are made up of atoms, which vibrate when thermal energy is received from an outside source. The greater the thermal energy received, the more vigorously the atoms vibrate. If the atoms are vibrating fast enough, it may emit light. Cooler objects emit primarily low frequency waves, while warmer objects emit waves with primarily higher frequencies. Therefore, objects at higher temperatures emit waves of high enough frequency to be visible and we start to see red colored objects, also known as "red hot" objects. If the temperature of an object continues to rise, the emitted wavelengths become even higher in frequency, and the observed color becomes orange or yellow. At even higher temperatures, the amount of visible light emitted by the object covers the entire visible spectrum about equally and our eyes see it as white. This is what is known as a "white hot" object.

According to my research, no matter what kind of materials an object is made of, it will glow white when its temperature is in the range of 1,500 to 11,000 K.

Carine Fang -- 2001