Sgr A* is believed to be the center of the Milky Way galaxy because
I.it lies in the general direction of the center of the galaxy based on observations of globular clusters in the plane of the Milky Way.
II.long-wavelength dust-penetrating images show it to be a region crowded with stars.
III.orbits of stars around it indicate a mass several million times that of the Sun within a volume a few light hours in size.
IV.radio observations show it is a concentrated source at the center of swirling clouds of gas.
A)I & II only
B)II & III only
C)I & IV only
D)II & IV only
E)All of I, II, III, & IV

Question

Sgr A* is believed to be the center of the Milky Way galaxy because 
I.it lies in the general direction of the center of the galaxy based on observations of globular clusters in the plane of the Milky Way.
II.long-wavelength dust-penetrating images show it to be a region crowded with stars.
III.orbits of stars around it indicate a mass several million times that of the Sun within a volume a few light hours in size.
IV.radio observations show it is a concentrated source at the center of swirling clouds of gas.
A)I & II only
B)II & III only
C)I & IV only
D)II & IV only
E)All of I, II, III, & IV

Quizplus · Accepted Answer

All four statements are true and provide evidence that Sgr A* is the center of the Milky Way galaxy. Statement I indicates that Sgr A* is in the general direction of the center based on observations of globular clusters in the plane of the Milky Way. Statement II suggests that Sgr A* is a region crowded with stars according to long-wavelength dust-penetrating images. Statement III notes that the orbits of stars around Sgr A* indicate a mass several million times that of the Sun, providing further support that it is the center of the galaxy. Statement IV adds that radio observations show that Sgr A* is a concentrated source at the center of swirling clouds of gas. Together, these four observations strongly suggest that Sgr A* is the center of the Milky Way galaxy.

Sgr A* Is Believed to Be the Center of the Milky