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Interstellar gas is composed mainly of 1)A) just hydrogen.B) ammonia, methane, and water vapor.C) 10% hydrogen, 90% helium by numbers of atoms.D) part hydrogen, yet mainly carbon dioxide.E) 90% hydrogen, 9% helium through weight.
What wake up to irradiate passing through also thin clouds that dust? 2)A) the motion causes the light of stars past to twinkle.B) that is motion reasons all irradiate to it is in red shifted together it passes with these clouds.C) the dims and reddens the irradiate of all much more distant stars.D) The light that passes though them is blue shifted as result of the cloud"s approach.E) also a little can completely block every light, such together the Horsehead Nebula.
i m sorry statement around dark dust clouds is true? 3)A) They deserve to be penetrated just with longer wavelengths such together radio and infrared.B) They consist of the majority of the mass of the Galaxy.C) They deserve to be penetrated just with much shorter waves, such together UV and X-ray.D) Hydrogen and also helium room the chief absorbing and scattering agents.E) castle block the vast majority of radio waves from ours Galaxy.
Some areas along the aircraft of the Milky method appear dark because 4)A) countless black holes absorb every light from those directions.B) there are no stars in these areas.C) stars in that region are surprise by dark dust particles.D) plenty of brown dwarfs in those areas absorb light, which lock turn right into heat.E) stars in that an ar are concealed by interstellar gas.
emissions nebulae like M42 happen only close to stars that emit big amounts the 5)A) X-rays and also gamma rays.B) visible light.C) infrared heat.D) ultraviolet radiation.E) microwaves.
What is the primary visible color of an emissions nebula? 6)A) blue as result of ionized helium atomsB) blue from the scattering of light turn off the small moleculesC) black, since of dustD) red because of reddening by dustE) red as result of ionized hydrogen atom
because of absorption of much shorter wavelengths by interstellar dust clouds, remote stars appear 7)A) brighter.B) bluer.C) redder.D) larger.E) to have a higher radial velocity.
The spectra the interstellar gas clouds present that they have the same straightforward composition together 8)A) interstellar dust.B) Earth"s atmosphere.C) the Martian polar caps.D) stars.E) none of the above.
i beg your pardon statement is true around the interstellar medium? 9)A) Dust is spread out uniformly v the galaxy.B) Dust blocks the longest electromagnetic wavelengths.C) Gas obscures the light from distant stars.D) we know an ext about the gas than the dust.E) Gas contains a the majority of carbon atoms.
The density of interstellar dust is very low, however it still block starlight since 10)A) the dust particles are irregular in shape.B) the is therefore cold the absorbs higher energy photons.C) over there is 100 times much more opaque gas than dust present in the ISM.D) the dust corpuscle are about the same size together the irradiate waves they absorb.E) ice particles reflect all light earlier toward your stars, not toward us.
What two points are needed to produce an emission nebulae? 11)A) hot stars and interstellar gas, specifically hydrogenB) hydrogen fusion and helium ionizationC) interstellar gas and dustD) cool stars and also much interstellar dustE) hydrogen gas and carbon dust
A huge gas cloud in the interstellar medium that consists of several type O and also B stars would certainly appearto united state as12)A) a dark patch versus a glowing background.B) a dark nebula.C) a enjoy nebula.D) an emission nebula.E) shining blue.
Neutral hydrogen atoms are best studied from their power given off as 13)A) Neutral hydrogen offers off no detectable radiation, because it is cold, no hot.B) 0.2 nm as X-rays.C) 121.3 nm as Lyman alpha emissions in the UV.D) 21-cm waves in the radio region.E) red hydrogen alpha emission, at 656.3 nm.
facility molecules in the interstellar medium are discovered 14)A) only roughly the supergiant stars choose Betelgeuse the make their heavy atoms.B) uniformly transparent the disk of the Galaxy.C) mainly in the thick dust clouds.D) ~ above the surface of the coolest class K and also M stars only.E) scattered evenly throughout the universe, a product that the huge Bang itself.
Why room dark dust clouds greatly misnamed? 15)A) The cloud is an illusion, for the dust is same distributed about the Galaxy.B) that is ice, not dust, which make them look at dark.C) Dust clouds execute radiate energy, but not as lot light as the stars do.D) lock contain much an ext gas than dust.E) all of the above are correct.
The average temperature of the usual dark regions in room are 16)A) 3,000 K. B) 0 K. C) 2.73 K. D) 100 K. E) 6,000 K.
as soon as an electron in hydrogen alters its spin native the same to the contrary direction as theproton, it17)A) neither emits no one absorbs a photon.B) absorbs a radio wave photon.C) emits an X-ray photon.D) absorbs a visible light photon.E) emits a radio wave photon.
Interstellar dust clouds are best observed in ~ what wavelength? 18)A) clearly shows onlyB) Visible and UVC) UV and also infraredD) Radio and X-rayE) Radio
i beg your pardon of these is no a consequence of dust in the interstellar medium? 19)A) red light from the emission nebulaeB) reddening that stars" light the passes with the dustC) the dark nebulae that block 90% the the Milky method from us visuallyD) blue reflection nebulae about the PleiadesE) every one of these are consequences.
it is crucial to research interstellar dust due to the fact that 20)A) over there is nearly as lot mass in between the stars together therre is in them.B) this is wherein stars are formed.C) old stars expel your matter below when castle die.D) all of the above.E) the not important at all.
have fun nebula have actually their blue colour because 21)A) they are an extremely high temperature.B) the interstellar dust absorbs the red light.C) the interstellar dust deflects the blue light.D) helium is the main absorber and emits irradiate in this colour.E) castle are really low temperature.
What is true of emission nebula? 22)A) they space often component of much larger interstellar clouds.B) their temperature deserve to exceed that of our sun.C) they are bigger than earth.D) they develop an emissions spectrum.E) every one of the above.
throughout the T-Tauri phase of a protostar, the 1)A) lies ~ above the key sequence.B) may build very solid winds.C) broadens dramatically.D) starts a period of reduced activity.E) transforms its spin direction.
What is the an important core temperature required for fusion? 2)A) 5,800 KB) 10 million KC) 3,000 KD) 100 million KE) 1 million K
i beg your pardon statement around the stages of starbirth is false? 3)A) atom reactions begin in the core by phase 4.B) The T-Tauri wind is prevalent in phase 5.C) By phase 3, the star has created a photosphere.D) At phase 1, just the cloud exists.E) By phase 7, the star has actually reached the main sequence.
On one H-R diagram, a protostar would certainly be 4)A) above and near the top left that the key sequence.B) above and to the ideal of the key sequence.C) top top the main sequence in ~ the too much lower right.D) below and also to the left that the main sequence.E) below and also near the ideal side the the main sequence.
The solitary most vital determinant of the temperature, density, radius, luminosity,and pace of development of a protostar is its5)A) magnetic field.B) molecular composition.C) mass.D) spin.E) chemistry composition.
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