Term
| in bohr's model of the atom, electrons.. |
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Definition
| only make transitions between orbitals of specific energies |
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Term
| Medium A blocks more of a certain wavelength of radiaton than medium B. Medium A has a higer... |
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Definition
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Term
| in astronomy, an interferometer can be used to |
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Definition
| improve the angular resolution of radio telescopes |
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Term
| increasing the temperature of a blackbody by a factor of 3 will increase its energy by a factor of |
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Definition
|
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Term
| The amount of diffraction and thus rge resolution of the scope depends upon |
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Definition
| the wavelength used and sze of the main telescope objective lens or mirror |
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Term
| the speed of light in a vaccuum is |
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Definition
|
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Term
| the primary purpose of a telescope is to |
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Definition
| collect a large amount of light and bring it into focus |
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Term
| most radio telescopes are laid out like which optical teescope design |
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Definition
|
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Term
| the observed spectral lines of a star are all shifted towards the red end of the spectrum |
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Definition
| this is an example of the doppler effect |
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Term
| green light has a shorter wavelength than orange light. in a 5 inch telescope, green light will |
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Definition
| provide better anglar resolution than orange light |
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Term
| what is the light gathering power of an 8 inch telescope compared to a 4 inch telescope |
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Definition
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Term
| the angular resolution of an 8 inch diameter telescope is _____ greater than that of a 2 indiamerter telescopech |
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Definition
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Term
| if a wave's frequency doubles and its speed stays constant, its wavelength |
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Definition
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Term
| a jar filled with gas is plaed directly in front of a second jar filled with gas. usinfspectroscopy to look at one jar through the other you obsrve dark spectral lines. the jar closest to you contains |
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Definition
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Term
| whcih of these is not a form of electromagnetic radiation |
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Definition
| dc current from your car battery |
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Term
| the two forms of electromagnetic radiation that experience the least atmospheric opacity are |
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Definition
|
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Term
| what is the resolution of a telescope |
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Definition
| the ability to distinguish two adjacent objects close togetehr in the sky |
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Term
| compared to a inch prime focus reflector, a 5 inch newtonian refector will |
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Definition
| have the same light gathering power |
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Term
| in the kelvin scale, absolute zero lies at |
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Definition
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Term
| thing that is the same for all forms of E-M radiation in a vaccuum |
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Definition
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Term
| what problem does adaptive optics correct |
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Definition
| urbulence in the arther atmosphere that creates twinkling |
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Term
| the sun's observed spectrum is |
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Definition
| is a continuum with absorption lines |
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Term
| spectral lines of molecules are |
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Definition
| more complex than those of atoms |
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Term
| as the sun rotates, an individual sunspot can be tracked across its face. frome astern to western limb, this takes about |
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Definition
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Term
| hat antural barrier usually prevents two protons form combining |
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Definition
| electromagnetic repulsion |
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Term
| which of these is not associated with the active sun |
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Definition
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Term
| from inside out, which is the correct order for the structure of the sun |
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Definition
| radiative zone, convective zone, chromosphere |
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Term
| suppose a large flare is detected optically, how long until radio interference arrives |
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Definition
|
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Term
| visible sun sopts lie in the |
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Definition
| granulation of the photosphere |
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Term
| what happens to the positrons produced by the nuclear reactions in the core of the sun |
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Definition
| they collide with electrons, producing energy |
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Term
| sunspots are dark splotches on the sun, which statment is true? |
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Definition
| hey are extremly hot, but cooler than surrounding areas of the sun |
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Term
| which is the net result of the proton-proton chain |
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Definition
| 4 protons= 1 helium4+ 2neutrinos+gamma rays |
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Term
| in the proton -proton cycle, the positron is |
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Definition
|
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Term
| while observing the sun, you note a large number of sunspots. what can you conclude? |
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Definition
| here are likely to be an above average number of flares and prominences |
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Term
| the outward pressure of hot gas in the sun |
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Definition
| is balanced by the inward gravitational pressure |
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Term
| the most striking example of a solar variability was the |
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Definition
| Maunder Minimun from 1645-1715 |
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Term
| the temperature of the photosphere is about |
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Definition
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Term
| during a period of high solar activity, the corona |
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Definition
|
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Term
| the proton-proton cycle, the helium aton and neutrino have less mass than the original hydrogen, wht happenes to the loss mass |
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Definition
| it is converted to energy |
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Term
| primary source of the suns energy os |
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Definition
| the strong force fusing hydrogen into helium |
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Term
| the solar winds blow outward from |
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Definition
|
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Term
| what two energy transport mechanisms, in order from outside the core to the surface, are found in the sun? |
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Definition
|
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Term
| what is the meaning of the solar constant? |
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Definition
| the amount of energy the earth recieves per unit area and unit time |
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Term
| hydroge "burning" by fusion reactions occurs only in the deep interior of the sun, because this is the only place in the sun where |
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Definition
| the requisite conditions of high temperature and high density occur |
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Term
| how long does the sunspot cycle last |
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Definition
|
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Term
|
Definition
| come in pairs, representing the north and south magneic fields. |
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Term
| which type of bunary do we get information about by looking at the intensity of the light |
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Definition
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Term
| two strs both have parallaxes of 0.023, but star A has apparent magnitud +2.3, while star B's magnitude is + 7.3. which statement is true? |
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Definition
| Star A is both 100X brighter and more luminous than star B |
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Term
| a star near the lower right of the H-R diagram is likely to be |
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Definition
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Term
| what can be said with certainty about a red star and blue star |
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Definition
| the blue star is hotter than the red star |
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Term
| a starts absolute magnitude is its apparent brightness as seen from |
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Definition
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Term
| in the H-R diagram what are the two most important data plotted |
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Definition
| spectral classes and absolute magnitudes |
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Term
| if Vega's apparent magnitude is zero and Deneb first magnitude, then |
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Definition
| Vega is 2.5 X brighter than Deneb |
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Term
| compared to a type A0 star, a type A9 star is |
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Definition
|
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Term
| what physical property of a star does the spectral type measure |
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Definition
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Term
| a star has a parallax of 0.01 arc seconds, its distance is |
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Definition
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Term
| which of these stars would be hottest |
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Definition
|
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Term
| light leaving a point source spreads out so that aparent brightness, I, of light per unit area vies with distance, d, accordint to which las |
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Definition
| I proportional to 1/d squared |
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Term
| suppose that two identical stars are located such that star A is at a distance of 5 pc and star B is at a distance of 25 pc. how will star B appear, compared to star A? |
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Definition
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Term
| which stament about stellar motion is incorrect |
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Definition
| proper motion is measured in intervals of 6 months |
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Term
| arent angular movement of a nearby star against the background stars as a consequence of its motion in space is known as |
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Definition
|
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Term
| on the H-R diagram, red supergiants like Betelgeuse lie |
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Definition
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Term
| which of thse binaries would appear most similar in color telescopically |
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Definition
|
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Term
- on the H-R diagram the sun lies
|
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Definition
| about the middle of the ain sequence |
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Term
| the doppler shift is used to find |
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Definition
|
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Term
|
Definition
| temperature VS luminosity |
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Term
| binary stars separated enough to be resolved in a tellescope are called |
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Definition
|
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Term
| the speed of a star, measured in a direction perpendicular to the line of sight from the earth to the star, is known as |
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Definition
|
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Term
| on the H-r diagram, white dwarfs Sirius B and Procyon B lie |
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Definition
|
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Term
| te star's color index is a quick way of determining its |
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Definition
|
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Term
| neutral hydrogen atoms are best studied from their energy given off as |
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Definition
| 21-cm waves in the radio region |
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Term
| when an electron in hydrogen changes its spin from the same to opposite direction as the proton it |
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Definition
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Term
| what two things are eeded to create an emission nebulae |
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Definition
| hot stars and interstellar gas, particularly hydrogen |
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Term
| the spectra of interstelar gas clouds show that they have basic composition asthe same |
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Definition
|
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Term
| reflection nebulae have their blue colour becuase |
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Definition
| the interstellar dust deflects the blue light |
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Term
| llas dust clouds are best observed at what wave length |
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Definition
|
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Term
| what is the primary visible color of an emission nebula |
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Definition
| red due to ionized hydrogen atoms |
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Term
| why are ark clouds largely misnamed |
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Definition
| they contain much mor egas than dust |
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Term
| whch statment about dark dust clouds is true |
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Definition
| they can be penetrted only with longer wavelengths such as radio and infrared |
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Term
| the average temperature of the typical dark regions in space are |
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Definition
|
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Term
| interstellar gas is composed maily of |
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Definition
| 90% hydrogen and 9 % helium by weight |
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Term
| the density of interstellar dustis very low, yet it still blocks starlight because |
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Definition
| the dust particles are about the same size as the light waves they absorb |
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Term
| which statement is true about the interstellar medium |
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Definition
| we know more about the gas than the dust |
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Term
| some regions along the plane of the milky way appear dark because |
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Definition
| stars in that region are hidden by dark dust particles |
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Term
| what is true of emission nebula |
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Definition
all of the above
their temperature can exceed that of our sun
they are bigger than earth
they produce emission spectrum
they are often part of much larger interstellar clouds |
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Term
| it is important to study interstellas dust because |
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Definition
old stars expel their matter here when they die
there is almost as much mass between the stars as there is in themthis is where stars are form
all of the above |
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Term
| due to absorbtion of shorter wavelengths by interstellar dust clouds, distant stars appear |
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Definition
|
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Term
| molecules in the interstellar medium are foundcomplex |
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Definition
| primarily in the dense dust clouds |
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Term
| which of these is not a consequence of dust in the interstellar medium |
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Definition
| red light from the emission nebulae |
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Term
| a large gas cloud in the interstellar medium that contains several type o and B stars would appear to us as |
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Definition
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Term
| what happens to light passing through even thin clouds of dust |
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Definition
| its dims and reddens the light of all more distant stars |
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Term
| what is not true of successful star formation |
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Definition
| planets are formed out of nebular cloud |
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Term
| In what stage of evolution is the forming star the brightes |
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Definition
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Term
| hat is the importance of nebular clouds that surround newly forming stars |
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Definition
| they add mass to the star during formation |
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Term
| which if the following statements about the rate of stellar evolution is true |
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Definition
| the more massive the original star, the faster the evolution |
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Term
| during the T-Tauri phase of a protostar, it |
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Definition
| may develop very strong winds |
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Term
| why are star clusters ideal " laboratories" for stellar evolution |
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Definition
| their stars are all about the same age, composition, and distance from us |
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Term
| a cloud fragment too small to collapse into a main sequence star becomes a |
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Definition
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Term
| a fragment of collapsing gas cloud that coes to equilibrium with central temperature of 4 million K will become |
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Definition
|
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Term
| approximatly how many brown dwarfs are beieved to exist in the milky way glaxy |
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Definition
|
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Term
| what is the critical core temperature required for fusion |
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Definition
|
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Term
| within a globular cluster, what would you expect to find in the population of stars |
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Definition
| many red giats, white dwarfs and dim reds but no bright blue stars nor dust or gas |
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Term
| which of the following are not very young stars or prestellar objects |
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Definition
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Term
| which of these would be the brightest star in an ancient globular cluster |
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Definition
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Term
| on an H-R diagram, a protostar would be |
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Definition
| above and to the right of the main sequence |
|
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Term
| why ar ethe majority of stars in the sky in the main sequence phase of their lives |
|
Definition
| this is the longst-lasting phase in eachs star's life |
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Term
| which of these would typically be the brightest star i a young open cluster? |
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Definition
|
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Term
| how long does it take an M-type star to reach the main sequence compared to a solar-type star? |
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Definition
| about twenty times longer |
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Term
| whcih is characteristic of globular star clusters |
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Definition
| old age and hundred of thounsands of stars, only about 50 parsecs wide |
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Term
| In what stage of evolution is a star formed? |
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Definition
|
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Term
| which stament about the stages of starbirth is false |
|
Definition
| nuclears reactions begin in the core by stage 4 |
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|
Term
| all globular clusters in our milky way are about how old |
|
Definition
| around ten billion years old |
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|
Term
| the single most important determinant of the temperature, density, radius, luminosity, and pace of evolutionof a protosar is its |
|
Definition
|
|
Term
| what are the characteristics of an open cluster of stars |
|
Definition
| a few hundred, mostly main sequence stars |
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|
