GLY 1001 Earth Science  Name:________________

Chapter 24 Part K: Key Terms

Fill in the blanks with the word(s) that best fit the description:

 

1. _______________ – The apparent brightness of a star if it were viewed from a distance of 10 parsecs (32.6 light years).  Used to compare the true brightness of stars.

 

2. _______________– The brightness of a star when viewed from Earth.

 

3. _______________– A galaxy having straight arms extending from its nucleus.

 

4. _______________– The theory that proposes that the universe originated as a single mass which subsequently exploded.

 

5. _______________– a massive star that has collapsed to such a small volume that the gravity prevents the escape of all radiation.

 

6. _______________– A cloud of glowing gas excited by ultraviolet radiation from hot stars.

 

7. _______________– A cloud of interstellar dust that obscures the light of more distant stars and appears as an opaque curtain.

 

Degenerate matter -

 

9. _______________– A galaxy that is round or elliptical in outline. It contains little gas and dust, no disk, or spiral arms, and few, hot bright stars.

 

10. _______________– A gaseous nebula that derives its visible light from the fluorescence of ultraviolet light from a star in or near the nebula.

 

11. _______________– A star that varies in brightness.

 

12. _______________– A system of galaxies containing from several to thousands of member galaxies.

 

13. _________________________– A plot of stars according to their absolute magnitudes and spectral types.

 

14. _______________– Relates the distance to a galaxy and its velocity.

 

15. _______________– The conversion of hydrogen through fusion to form helium.

 

16. _______________– Dust and gases found between stars.

 

17. _______________– A galaxy that lacks symmetry

 

18. _______________Light-year – The distance light travels in a year, about six trillion miles.

 

19. _______________Local Group – The cluster of 20 or so galaxies to which our galaxy belongs.

 

20. _______________Magnitude – A number given to a celestial object to express its relative brightness.

 

22. _______________– A sequence of stars on the Hertzsprung-Russell Diagram, containing the majority of stars, that runs diagonally from upper left to lower right.

 

23. _______________– A cloud or stellar gas and/or dust.

 

24. _______________– A star of extremely high density composed entirely of neutrons.

 

25. _______________ - A star that explosively increases in brightness.

 

26. _______________– A shell of incandescent gas expanding from a star.

 

27. _______________– A collapsing cloud of gas and dust destined to becomes a star.

 

28. _______________ – A variable radio source of small size that emits radio pulses in very regular periods.

 

29. _______________- A variable star that pulsates in size and luminosity.

 

30. _______________– A large, cool star of high luminosity, a star occupying the upper-right portion of the Hertzsprung-Russell Diagram.

 

31. _______________– A relatively dense dust cloud in interstellar space that is illuminated by starlight.

 

32. _______________– A flattened, rotating galaxy with pinwheel-like arms of interstellar material and young stars winding out from its nucleus.

 

33. _______________– A measure of stellar distance.

 

34. _______________– A very large star of high luminosity.

 

35. _______________– An exploding star that increases in brightness many thousands of times.

 

36. _______________– A star that has exhausted most or all of its nuclear fuel and has collapsed to a very small size; believed to be near its final stage of evolution.

 

Chapter 24 Word List

Absolute magnitude

Apparent magnitude

Barrel spiral galaxy

Big bang

Black hole

Bright nebula

Dark nebula

Degenerate matter

Elliptical galaxy

Emission nebula

Eruptive variables

Galactic cluster

 

Hertzsprung-Russell (H-R) diagram

Hubble’s law

Hydrogen burning

Interstellar dust

Irregular galaxy

Light-year

Local Group

Magnitude

Main-sequence stars

Nebula

Neutron star

 

Nova

Planetary nebula

Protostar

Pulsar

Pulsating variables

Red giant

Reflection nebula

Spiral galaxy

Stellar parallax

Supergiant

Supernova

White dwarf