Term
| Why are star clusters ideal "laboratories" for stellar evolution |
|
Definition
| Their stars are all about the same AGE, COMPOSITION, AND DISTANCE from us. |
|
|
Term
| What are the characteristics of an open cluster of stars? |
|
Definition
| a few hundred, mostly main-sequence stars |
|
|
Term
| Which is characteristic of globular star clusters? |
|
Definition
| old age and hundreds of thousands of stars, only about 30 ly wide |
|
|
Term
| on an H-R diagram, a protostar would be |
|
Definition
| above and to the right of the main sequence. |
|
|
Term
| A newly formed protostar will radiate primarily at which wavelength |
|
Definition
|
|
Term
| Neutral hydrogen atoms are best studied from their energy given off as |
|
Definition
|
|
Term
| The most common molecule in a molecular cloud is |
|
Definition
|
|
Term
| A large gas cloud in the interstellar medium that contains several type O and B stars would appear to us as |
|
Definition
|
|
Term
| What two things are needed to create an emission nebulae? |
|
Definition
| hot stars and interstellar gas, particularly hydrogen |
|
|
Term
| Some regions along the plane of the Milky Way appear dark because |
|
Definition
| stars in that region are hidden by dark dust particles. |
|
|
Term
| A star has a parallax of 0.01 arc seconds. Its distance is |
|
Definition
|
|
Term
| If Vega is apparent magnitude zero, and Deneb first magnitude, then |
|
Definition
| Vega is 2.5× brighter than Deneb. |
|
|
Term
| What physical property of a star does the spectral type measure? |
|
Definition
|
|
Term
| Which of these stars would be the hottest? |
|
Definition
|
|
Term
| What can be said with certainty about a red star and a blue star? |
|
Definition
| The blue star is hotter than the red star. |
|
|
Term
| The star's color index is a quick way of determining its |
|
Definition
|
|
Term
|
Definition
| temperature versus luminosity. |
|
|
Term
| On the H-R diagram, the bright blue stars that dominate the naked-eye sky lie |
|
Definition
|
|
Term
| On the H-R diagram, white dwarfs Sirius B and Procyon B lie |
|
Definition
|
|
Term
| The temperature of the photosphere is about |
|
Definition
|
|
Term
| Given that a large sunspot, about 100× smaller than the Sun, is about the same size as our planet, how many Earths could fit inside the Sun's vast volume? |
|
Definition
|
|
Term
| The density of the Sun is most similar to which object? |
|
Definition
|
|
Term
| What two energy transport mechanisms, in order from outside the core to the surface, are found |
|
Definition
| radiative diffusion, convection |
|
|
Term
| How long does the sunspot cycle last, on average? |
|
Definition
|
|
Term
|
Definition
| come in pairs, representing the north and south magnetic fields. |
|
|
Term
| Sunspots are dark splotches on the Sun. Which statement is true? |
|
Definition
| They are extremely hot, but cooler than the surrounding areas of the Sun. |
|
|
Term
| The critical temperature to initiate the proton-proton cycle in the cores of stars is |
|
Definition
|
|
Term
| In the proton-proton cycle, the helium atom and neutrino have less mass than the original hydrogen. What happens to the "lost" mass? |
|
Definition
| it is converted to energy |
|
|
Term
| what temperature is needed to fuse helium into carbon? |
|
Definition
|
|
Term
| a star is on the horeizontal branch of the H-R diagram. Which statement is true? |
|
Definition
| It is burning both HYDROGEN and HELiUM |
|
|
Term
| During the hydrogen shell burning phase |
|
Definition
| the star grows MORE luminous |
|
|
Term
| Compared to our Sun, a typical white dwarf has |
|
Definition
| about the same mass and a million times higher density |
|
|
Term
| Of the elements in your body, the only one not formed in stars is |
|
Definition
|
|
Term
| An iron core cannot support a star because |
|
Definition
| iron cannot fuse with other nuclei to produce energy |
|
|
Term
| Type II supernovae occur when their cores start making |
|
Definition
|
|
Term
| If it gains sufficient mass, a white dwarf can become a |
|
Definition
|
|
Term
| A recurrent nova could eventually build up to a |
|
Definition
|
|
Term
| Noting the turnoff mass in a star cluster allows you to determine its |
|
Definition
|
|
Term
| The helium flash converts helium nuclei into |
|
Definition
|
|
Term
| A solar-mass star will evolve off the main sequence when |
|
Definition
| it builds up a core of inert helium |
|
|
Term
| Two important properties of young neutron stars are |
|
Definition
| extremely rapid rotation and a strong magnetic field. |
|
|
Term
| Who discovered the first four pulsars? |
|
Definition
|
|
Term
| The densely packed neutrons of a neutron star cannot balance the inward pull of gravity if the total mass is |
|
Definition
| greater than Schwalimit of 3 solar masses. |
|
|
Term
| An observer on planet sees a spaceship approaching at 0.5c. A beam of light projected by the ship would be measured by this observer to travel at |
|
Definition
|
|
Term
| The largest known black holes |
|
Definition
| lie in the cores of the most massive galaxies |
|
|
Term
| You would expect millisecond pulsars to be |
|
Definition
|
|
Term
|
Definition
|
|
Term
| What explanation does general relativity provide for gravity? |
|
Definition
| Gravity is the result of curved spacetime. |
|
|
Term
| If light from a distant star passes close to a massive body, the light beam will |
|
Definition
| bend towards the star due to gravity. |
|
|
Term
| A method for identifying a black hole is to |
|
Definition
| look for their effects on nearby companions |
|
|
Term
|
Definition
|
|
