Radio maps of the spiral arms of our galaxy
a. reveal that our galaxy is a grand design spiral.
b. map the location of hot O and B stars by the radio radiation they emit.
c. reveal that the spiral arms are winding up and growing closer together.
d. reveal that the Sun is currently located in the center of a spiral arm.
e. map the location of dense neutral hydrogen clouds.
Question 2
________ are star-like objects that contain less than 0.08 solar masses and will never raise their core temperatures high enough that the proton-proton chain can begin. Other minor fusion reactions do occur in these objects. They fall in a gap between the low-mass M dwarf stars and the massive planets in which nuclear fusion never occurs.
a. Brown dwarfs
b. Herbig-Haro objects
c. Bok globules
d. T-Tauri star
e. Main-sequence stars