Spectra for the Cygnus loop and the Orion nebula are shown above. Judging from their spectra, how would these two objects look to the naked eye (assuming they were bright enough for colors to be distinguished)?
A)The Cygnus loop would appear blue, and the Orion nebula would appear blue.
B)The Cygnus loop would appear red, and the Orion nebula would appear red.
C)The Cygnus loop would appear blue, and the Orion nebula would appear red.
D)The Cygnus loop would appear red, and the Orion nebula would appear blue.

Question

Spectra for the Cygnus loop and the Orion nebula are shown above. Judging from their spectra, how would these two objects look to the naked eye (assuming they were bright enough for colors to be distinguished)?
A)The Cygnus loop would appear blue, and the Orion nebula would appear blue.
B)The Cygnus loop would appear red, and the Orion nebula would appear red.
C)The Cygnus loop would appear blue, and the Orion nebula would appear red.
D)The Cygnus loop would appear red, and the Orion nebula would appear blue.

Quizplus · Accepted Answer

The Cygnus loop has strong emission lines in the blue part of the spectrum, indicating that it emits mostly blue light. The Orion nebula has strong emission lines in the red part of the spectrum, indicating that it emits mostly red light. Therefore, the Cygnus loop would appear blue and the Orion nebula would appear red to the naked eye (assuming they were bright enough for colors to be distinguished).

Spectra for the Cygnus Loop and the Orion Nebula Are