1.
Please help with the following.
True or False On an H-R diagram, OB association stars are found between the birthline and the
main sequence. T Stars convert hydrogen to helium through a series of complex chemical
reactions.T The Coulomb repulsion in the 1st step of the CNO cycle requires a minimum
temperature of 16 million K for fusion to occur. T The Sun produces 10% of its energy by the
carbon nitrogen oxygen cycle. T Helium-3 is produced in the 2nd step of the proton-proton
chain. T 1. 2. 3. 4. 5.
Solution
1) False
OB associations are groups of stars born together but not bound to each other by their mutual
gravity.
T Tauri Stars
Solar mass objects that have just emerged from their cocoons and are located in the H-R
Diagram between the birthline and the main sequence.