Stellar Astrophysics

2. When gravity and pressure balance, a star is in ___ equilibrium.
4. A collapsing protostar reaches quasi-static stability when it crosses the ___ boundary.
7. The upper limit on the mass of a white dwarf is known as the ___ mass.
10. A neutron star with a very high magnetic field is known as a ___.
11. The star ___ became surprisingly dim last winter.
12. Pressure support in brown dwarf comes from electron ___.
13. The time scale for a star to collapsed fueled only by liberated gravitational potential energy.
17. The quantity X is the mass fraction of ___.
18. The process by which protons capture electrons in the core of a massive, collapsing star.
20. The effective temperature of a star is not a ___.
21. The radius at which nothing an escape from a black hole is known as the ___ radius.
24. Circumstellar disks around young stars are known as ___.
25. Massive planets orbiting close to their host stars are known as hot ___.
27. The triple alpha process in stars produces the element ___.
28. The peak in the fusion probability is known as the ___ peak.

1. A pulsating horizontal branch star is known as an ___ variable.
3. The word ___ describes the expansion or contraction of gas without exchanging energy with its surroundings.
5. The easiest place to detect Earth-like planets is around __ stars.
6. Proton-proton fusion in stars is able to proceed due to quantum ___.
8. As an interstellar gas cloud collapses, it undergoes ___.
9. Helium fusion begins in stars at the end of the ___ phase.
14. Elements heavier than Fe are mostly produced when heavy nuclei capture ___.
15. Most exoplanets have been discovered using the ___ method.
16. We can determine an exoplanet's ___ from radial velocity variations.
17. the gap between the main sequence and the red giant branch is known as the ___ gap.
19. A commonly used initial mass function.
22. An assumption of ___ means that all regions of a stars structure change in the same degree.
23. Following the helium flash, stars land on the ___ branch in the HR diagram.
25. – The condition under which an interstellar cloud will collapse to form stars is known as the ___ criterion.
26. Main sequence stars above 2 solar mases get energy from the ___ cycle.