Stars

3. The process by which a star changes over the course of its lifetime, including its birth, life phases, and eventual death.
5. A star that is in the process of evolving into a giant as it leaves the main sequence.
9. A large, luminous star in a late stage of stellar evolution, characterized by its expanded size and is fueled by helium fusion in its core.
12. A spectrum of electromagnetic radiation transmitted through a substance, showing dark lines or bands at specific wavelengths.
14. The stage in a star's life cycle during which it fuses hydrogen into helium in its core, characterized by a stable equilibrium between inward gravitational force and outward radiation pressure.
15. A catastrophic explosion that occurs at the end of a massive star's life cycle, resulting in a sudden and extreme increase in brightness.
16. A celestial body consisting of a mass of gas held together by its own gravity and emitting light and heat.
18. The temperature of a star's outer layer, which influences its color and spectral characteristics.
19. A system in which two stars orbit around their common center of mass, either bound gravitationally or merely appearing close together in the sky.
20. A condensation of gas and dust in space with a mass less than that of the Sun but with the potential to become a star.

1. A graphical representation of stars' luminosity plotted against their surface temperature, used to classify stars and understand stellar evolution.
2. A classification system for stars based on the characteristics of their spectra, often denoted by letters such as O, B, A, F, G, K, and M.
3. The study of the interaction between matter and electromagnetic radiation, particularly analyzing the spectrum of light emitted or absorbed by substances.
4. A spectrum of electromagnetic radiation emitted by a substance, showing bright lines or bands at specific wavelengths.
6. A highly compact object composed primarily of uncharged particles, formed from the collapsed core of a massive star.
7. The displacement of spectral lines toward shorter wavelengths in the radiation emitted by an object caused by the object's motion toward the observer.
8. A small, dense remnant of a medium mass star that has exhausted its nuclear fuel, consisting mostly of electron-degenerate matter.
10. This which determines a stars evolutionary path and ultimate fate.
11. The total amount of energy emitted by a star per unit time, often is describing something visual
13. An astronomical object with a gravitational pull so strong that nothing, not even light, can escape from it beyond the event horizon.
17. The displacement of spectral lines toward longer wavelengths in the radiation emitted by an object caused by the object's motion away from the observer.