Radiation from stars may be characterized by the Stefan–Boltzmann law by assuming the star is one of these objects. For 10 points each:
[10m] Name these ideal, diffuse emitters. These objects have an energy spectrum given by the Planck distribution.
ANSWER: blackbodies [or black-body]
[10h] This satellite’s Differential Microwave Radiometers confirmed that the Cosmic Microwave Background is a near-perfect blackbody with faint anisotropies. This first satellite to study the CMBR in depth was succeeded by WMAP.
ANSWER: COBE [or the Cosmic Background Explorer or Explorer 66]
[10e] The Stefan–Boltzmann law relates the radiant exitance of an object to the fourth power of this quantity, which can be used to define an “effective” form of it for stars. The CMB acts as a blackbody with a value of about 2.7 Kelvin for this quantity.
ANSWER: temperature [accept effective temperature]
<JC, Physics - Astronomy>