Lab 4: Angles in Astronomy- Parallax

Angular Size

The ________ ________ is the size of an object measured in angles.

The ________ ________ is the actual size of an object.

• S= ________ ________ (doesn't change)
• θ= ________ ________ (does change)
• D= ________

As the distance ________, the angular size ________.

To convert to radians (θ_rad) from degrees:

Parallax

Parallax is the apparent change in position of ________ objects relative to ________ objects as the observer changes position.

The radius of earth's orbit around the sun is ___ ________ ________.