# Does any gravitating body emit Hawking radiation?

1. Mar 17, 2012

### johne1618

The Hawking-Unruh temperature is given by the expression:

$\large T = \frac{\hbar g}{2 \pi c k}$

where g is the gravitational acceleration at the surface of a black hole.

Does this expression imply that any gravitating body will emit Hawking radiation?

For example if we take the acceleration due to gravity at the Earth's surface to be $g = 10 \ m/s^2$ does that mean that the Earth emits Hawking radiation at a temperature $T = 10^{-20} K$?

John

2. Mar 17, 2012

### zhermes

No. You have to have an event horizon to produce hawking radiation; but any body with an event horizon should do that (few examples besides black-holes).