If a star's apparent visual magnitude is equal to its absolute visual magnitude, how far is the star located from Earth?
a. 0 pc b. 1 pc
c. 10 pc d. 100 pc
Question 2
An isolated black hole in empty intergalactic space would be difficult to detect because
a. there would be no stars behind it whose light would be affected by gravitational lensing.
b. it could not emit light from inside its event horizon.
c. no companion stars would be affected by its gravitational field.
d. no matter would be falling into it to create an X-ray-emitting accretion disk.
e. All of the other choices are correct.
The Sun is the star at the center of the Solar System.
Apparent and True Orbits of Alpha Centauri.
A Star with Three Planets
Drug A is more potent than Drugs B and C. Drugs A and C have equal efficacy because both drugs have ...
Testing visual fields by confrontation
Smooth Brittle Star.