How do the spectra of H II regions differ from the spectra of reflection nebulae? Why?

Q: The dust in a molecular cloud has a temperature of about 34 K. At what wavelength (in nm) does it…

A: temperature = T = 34 K wavelength = λmax=?

Q: What is the peak wavelength of an O star of temperature 50,000 K? What range of the spectrum is…

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Q: Explain why the sky is blue and how that relates to reflection nebulae.

A: Dispersion. Despersion is a phenomena in which when light passes beteen 2 particle it disperses.

Q: The apparent V magnitude of Sirius is -1.44. What is its distance in parsecs? Use your estimate of…

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Q: What is nebulae?

A: The  cloud of dust and gas that is known to fill up the space between stars in the solar system such…

Q: Which two spectral types were added to the spectral sequence after 1998?   a. O and B   b. K and M…

A: We define "Spectra of a star" as the elements absorbed by them. So based on the spectral…

Q: How does the extreme temperature sensitivity of the CNO cycle affect the structure of stars?

A: As a result of the extreme temperature dependence of CNO burning, those stars that are dominated by…

Q: Now, rank the same objects by increasing temperature. For spherical objects, use the surface…

A: Intercloud gas: The gases other than intersteller gases present in space are known as intercloud…

Q: If the two stars orbit in a such a way that the big star is 4 AU from the center of the mass and the…

A: Given:distance of larger star from COM, ra = 4 AUdistance of smaller star from COM, rb = 12 AUtotal…

Q: If the Sun is well approximated by a black body with a temperature of 6,000◦ K, then how does its…

A: By using Stefan Boltzmann's Law

Q: The rate at which a nebular cloud rotates increases as the cloud collapses to form systems of stars…

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Q: If a contracting protostar is 0.5 times as luminous as the Sun and has a temperature of only 1,500…

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Q: The rate at which a nebular cloud rotates increases as the cloud collapses to form systems of stars…

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Q: Suppose a planetary nebula is 3.5 pc in diameter, and Doppler shifts in its spectrum show that the…

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Q: Relate hydrostatic equilibrium to the star's mass, composition, and evolution off the main sequence.

A: Hydrostatic equilibrium means that the inward force of gravity,a product of the star's mass, is…

Q: If a protostellar disk is 240 AU in radius and the disk plus the forming star together contain 9…

A: Given Radius r = 240 AU Mass m = 9 Solar mass Known Values 1 AU = 1.496 x 1011 m 1 solar mass =…

Q: describe the characteristics of the various kinds of interstellar gas (HII regions, neutral hydrogen…

A: Star formation is generally more active in the denser, inner part of the Milky Way than in the outer…

Q: Arrange these statements in order according to the Nebular theory 1. X Heating interstellar cloud…

A: Answer is 1.Nearby cataclysmic explosion of supernova occurred                 2. Interstellar cloud…

Q: Suppose a planetary nebula is 4.3 pc in diameter, and Doppler shifts in its spectrum show that the…

A: The expression for find age of planetary nebula is t=Rv=d2v

Q: Use the small-angle formula to find the linear diameter of a radio source with an angular diameter…

A: Given :- angular diameter of radio source = 0.0024 arc seconds. distance = 2.30 Mpc .

Q: The rate at which a nebular cloud rotates increases as the cloud collapses to form systems of stars…

A:

Q: The radius of the nebula is about 0.401 light-years. The gas is expanding away from the star at a…

A: Given that, r=0.401 light year1 light year=9.46×1015 mr=0.401×9.46×1015=3.79×1015 mThe particle at…

Q: Describe how energy generated in the core of a 1-solar-mass star gets to the star's surface.

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Q: If you assume that a globular cluster 6 arc minutes in diameter is actually 27 pc in diameter, how…

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Q: Use t =  1 M2.5 to compute the life expectancy of a 0.8-solar-mass star. (A solar lifetime is…

A: According to question--- Given data - M = 0.8  We have to find- compute the life expectancy ?

Q: The current precision of the Doppler shifts in the absorption lines in stellar spectra is ~3 km s-1.…

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Q: which of the following describes the physical characteristics of Barnard’s star?

A: The Bernard's Star is a red dwarf which is approximately 6 light-years away from the Earth.…

Q: What is the radius event horizon for Cygnus-X1?

A: Cygnus-X1 is an enormous X-rays source & assumed to be the first black hole. It is about 6070Ly…

Q: What kind of object is the Messier Object M42, and where is it in the sky?

A: Messier object M42 is brightest Orion nebulae .

Q: If a giant molecular cloud has a diameter of 56 pc and drifts relative to nearby objects at 19 km/s,…

A: Given that :Drift= 19 km/s       =0.019 m/sDiameter= 56pc             =56 x 3.1 x 1016 m…

Q: Show that the total luminosity of the disk is related to the total surface density at the centre I(R…

A: first we have to show integral for I(R=0) Then we have to proceed for the total luminosity of the…

Q: The rate at which a nebular cloud rotates increases as the cloud collapses to form systems of stars…

A: Given that:Mass of nebular cloud, m=1.9×1027 kgInitia tangential velocity, vi=6.8 km/s=6800…

Stellar evolution

We may see thousands of stars in the dark sky. Our universe consists of billions of stars. Stars may appear tiny to us but they are huge balls of gasses. Sun is a star of average size. Some stars are even a thousand times larger than the sun. The stars do not exist forever they have a certain lifetime. The life span of the sun is about 10 billion years. The star undergoes various changes during its lifetime, this process is called stellar evolution. The structure of the sun-like star is shown below.

Red Shift

It is an astronomical phenomenon. In this phenomenon, increase in wavelength with corresponding decrease in photon energy and frequency of radiation of light. It is the displacement of spectrum of any kind of astronomical object to the longer wavelengths (red) side.