astronomy chapter 17

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50 terms · chapter 17

a nearby star has aparallax of .2 arc seconds, what is its distance

5 parsecs

what is proper motion

it is the annual apparent motion of a star across the sky

which statement about stellar motion is incorrect

like parallax, proper motion is measured over intervals of exactly six months

which of the following best describes the size and distance relationship of our sun and the nearest star

two golf balls separated by 100 kilometers

if a star has a parallax of .05, then its distance in light years is about

65 light years away

if a star is found by spectoscopic observations to be about 500 parsecs distant, its parallax is

.002"

hipparcos observations have given us good data on stars out to about

200 parsecs

about how many stars has hipparcos given us accurate distance data on

a millon, those with parallaxes of .005" or larger

procyon lies about 13 light years distant, thus its parallax is about

.25"

in order to turn a star's proper motion into its space velocity, we must also know

the distance and radial velocity

if a star appears to move back and forth relative to other stars over a six-month period, this motion is due to the star's

parallax shift

if a star appears to move relatie to other stars over a one year period, this motion is due to the star's

transverse motion or true space motion

what is the absolute magnitude of our sun

+4.8

the absolute magnitude of a star is its brightness as seen from a distance of...

ten parsecs

perhaps the greatest of the greek astronomers____compiled the first catalog of stars accurately measured their positions, and defined the basic system of stella brigthness

hipparchus

in comparing first magnitude Deneb will second magnitude Polaris, we find that....

Deneb appears 2.5 times brighter to us than does Polaris

at the distance of jupiter (6 times further away from the sun than the earth) the amount of sunligth received per square centimeter different by waht factor

36 times less (inverse sqaure law)

Star A and star B have an apparent magnitude of 4.0 but star A has an absolute magnitude of 1.0 and star B has an absolute maginuted of 7.0 then...

star A and star B appear to have the same brightness, but actually star A is brighter than star B

star A snd B have the same apparent magnitude of 7.0. but star A is at a distance of 15 pc and star B is at a distance of 30 pc...then

star A and B appear to have the same brigthness, but actually star B is brighter thans star A

star A and B both have an absolute magnitude of 2.0 but star A is at a distance of 50 pc and star B is at a distance of 20 pc...then

star B appears brighter than star A, but actually star A and B are the same brightness

star A and star B have an absolute magnitude of 2.0 but star A has an apparent magnitude of 5.0 and star B of 7.0..then

star A appears brighter than star b, BUT in actuallity both have the same broightness

star A has an absolute magnitude of 2.5 and star B an apparent magnitude of 2.5, but star A is a main sequence star an star B is a red giant...then

its impossible to dtermine how bright they are given the information

what are the two most important intrinsinc properties used to classify stars

luminosity and surface temperature

what physical property of a star does the spectral type measure

temperature

the star's color index is a quick way of determining its

temperature

the most famous G type star is

the sun

star A is a main sequence star of spectral type F2 and star B is a white dwarf of spectral type..then

star B is hotter than star A

star A is a main sequence star of spectral type G5 and star B is a red giant of spectral type k2..THEN

star A is hotter than star B

stars that have masses similar to the sun's and sizes similar to the earth are...

white dwarfs

compared to the size of the sun, between what range of sizes are most stars found

.01to 100 solar radii

on the H-R diagram , the sun lies

about the middle of the main sequence

which of the following is th emost commno type of star

low mass main sequence

the H-R diagaram plots ______ against the spectral type or temperature

luminosity or absolute magnitude

how might th emost common occurring stars be described, based on our stellar neighbrohood?

M, main sequence

on the HR diagram, red supergiants like Betelguese lie

at the top right

on the HR diagram white dwarfs like Sirius B and Procyon B lie

at the lower left

in the HR diagram, the bright blue-white stars that dominate the naked eye sky lie to the ...

top left

having nothing to do with trigonometry ____parallaxes use the width or absorption lines to estimate the stars luminosity and size and distance

spectroscopic

in general the narrower the spectral line of a star

the bigger the star is

upon what data do measurments of sizes of eclipsing binaries depend

their dopler shifts and durations of stages of their eclipses

which type of binary can have sizes measured directly by photometry

eclipsing

in what range of masses are most stars found

.1-100 solar masses

in a visual binary system with circular orbits, if in 20 yrs the two stars position angles have shifted 30 degree, the pair's period must be

240 years

in a spectroscopic binary system, the star showing the larger blue shift is...

less massive and approaching us at this moment

in a spectroscopic binary, if a pair shows a combined set of line tonight, but a maximum split two nights later , its orbital period must be

8 days

what is the single most important characteristic in determening the course of a star's evolution

mass

what is the typical main sequence lifetime of a M-type star

a trillion years

what os th etypicall lifetime of a G-type star

10 billion years

what is the typical life time of a B type star

20 milion years

for a star 10 solar masses, its main sequence life span will be

only 1/1000th of the sun

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