Stellar Evolution + Galaxies
Order by
32 terms
Terms | Definitions |
|---|---|
 stellar evolution | stars change size and temperature due to the creation of new elements in the core by nuclear fusion |
| mass | controls the life-cycle of all stars |
| sun | g2 |
| blue giants | high mass, short contraction 10-20 solar masses |
| a,f,g and k | medium mass, medium contraction 1-3 solar masses |
| red dwarf | low mass, long contraction less than 1 solar mass |
| nebula | cloud of gas and dust that contracts under gravity |
| 4H-1He | conversion in the main sequence |
| He-C | conversion that makes a red giant |
| He-C, C-O, O-Si, Si-Fe | conversion that makes a supergiant |
| pulsar | 1.4-3 solar masses, "lighthouse in space", spins very fast |
| neutron star | 1.4-3 solar masses, spins very fast, beam out of view |
| black hole | greater than 3 solar masses |
| singularity | black hole itself |
| event horizon | point of no return |
| iron | has the densest nucleus of all elements and is the densest element a star can produce in its core |
| supernova | when a star tries to make an element heavier than iron in its core and the gravity and fusion pressure combine and tear apart the star |
| optical double | two stars that appear to be double by chance line of sight, not related by gravity |
| visual binary | two or more stars that can be "split" when viewed through a telescope, mass can be determined |
| eclipsing binary | two stars that eclipse each other due to their orbit being in earth's line of sight, star changes in brightness due to eclipse |
| spectroscopic binary | two or more stars that cannot be visually split but can be identified by the alternating red and blue shifting of their spectra |
| variable stars | unstable stars that vary in brightness due to changes in size, period is related to true brightness therefore they can be used to determine distance |
| rr lyrae | short period variable less than one day |
| cepheid | medium period variable a few days to a couple months if the period is bigger it gets brighter |
| mira variable | long period variable months to years, red giants |
| nova | white dwarf in a binary pair temporarily flares up when hydrogen stolen from the partner star builds on the white dwarf and finally fuses |
| galaxy | large system of stars controlled by common gravity, also means "island universe" |
| elliptical galaxy | egg-shaped galaxy |
| spiral galaxy | bulge or nucleus, disc or spiral arms, comes in a barred type (galaxy) |
| irregular galaxy | no basic shape (galaxy) |
| open cluster | loosely formed group of stars of similar origin |
| globular cluster | nearly spherical group of densely packed stars |
First Time Here?
Welcome to Quizlet, a fun, free place to study. Try these flashcards, find others to study, or make your own.