# Will a black body placed somewhere around the Sun obtain (eventually) the same temperature as the Sun?

Suppose we look (above the Earth's atmosphere) at the wavelength ($$=\frac c f)$$ spectrum emitted by the Sun:

This shows that the Sun is approximately a black body with a temperature of about $$5525(K).$$ Now If we place a black body at a distance $$l$$ from the Sun will the radiation coming from the Sun (after a while, depending on $$l$$) causes this black body to have a temperature of $$5525(K)$$ too (by means of the blackbody radiation corresponding to the Sun), or will this only happen when the black body is completely surrounded completely by a material at $$5525(K)$$ (implying that the black body we place somewhere around the Sun is in a state of dynamical equilibrium)? Somewhat like a thermometer put in interstellar space will show a temperature of $$2.7(K)$$ because it's surrounded at all sides by the CMBR.

• Have you thought that the earth is in a fist approximation a black bod an $l$ distance from the sun? – anna v Jan 15 at 16:57
• Yes, that's why I thought that a dynamic equilibrium would develop: at daytime, the Earth absorbs energy, while at nighttime, the Earth radiates energy away. I can remember that I once asked in this question physics.stackexchange.com/questions/245691/… if the rotation of the Earth was a necessary condition for life to develop. Thanks for the comment. – descheleschilder Jan 15 at 17:38