Saturn has a very hot interior, reaching 11,700 C at the core, and the planet radiates 2.5 times more energy into space than it receives from the Sun.

The effect of albedo on temperature can be approximated by assuming that the energy absorbed is multiplied by 0.7, but that the planet still radiates as a black body (the latter by definition of effective temperature, which is what we are calculating).

That planet radiates a lot of heat, enough so the satellite is tolerably warm around the equator even at night.

Novas and ringed planets and miniature lightning bolts and curly-tailed comets radiated from their mouths in confusing profusion and wonderful foulness, with the whale spouting obscene curlicues.

Scientists believe the planet absorbs nearly all the sunlight and radiates it into space as heat.

Although absolute negative temperatures are not impossible, it would mean that the planet is incredibly hot and radiating massive amounts of radiation, which is the opposite of how it is portrayed in the episode.

This planet radiates boredom.

The sixth planet however, which shows no sign of industrial advancement at all, radiates energy transmissions that Communications Officer Lt. Uhura states as contradictory to its technological scale.

Venus must be still very hot as young planets radiate heat.

Any civilized planet radiates like a small star in the radio range.