Science

2. Gaseous cloud from which, in the so-called nebular hypothesis of the origin of the solar system
4. Shows the relationship between a star's temperature and its luminosity
5. Amount of matter in an object
10. Generates a strong magnetic field
12. Group of stars that forms a particular shape
13. The angle between the Earth at one time of year, and the Earth six months later, as measured from a nearby star
15. One in which two stars orbit around a common center of mass
17. The range of all types of EM radiation
19. Apparent magnitude an object would have if it were located at a distance of 10 parsecs
21. The stellar core left behind after a dying star has exhausted its nuclear fuel and expelled its outer layers to form a planetary nebula

1. Pulses of radiation at very regular intervals that typically range from milliseconds to seconds
3. A dying star in the final stages of stellar evolution
6. The explosion of a star
7. Property of a body by virtue of which it opposes any agency that attempts to put it in motion
8. Process in which two or more things form to make one thing
9. Brightest star in the night sky
11. How bright an object appears in the sky from Earth
14. One of many large rocks that circle the sun
16. A piece of rock or other matter from space that produces a bright light as it travels through the atmosphere
18. a celestial object consisting of a nucleus of ice and dust
20. Force by which a planet or other body draws objects toward its center