Choose the correct statements from the following list referring to white dwarfs. (Give ALL correct answers, i.e., B, AC, BCD...) A) The pressure that balances gravity in a white dwarf is called degenerate electron pressure.   B) The power source of white dwarfs is left-over heat.   C) White dwarfs cool slowly because they are small and eventually fade-out to become black dwarfs.   D) White dwarfs with mass greater than 1.4 times the Sun's mass cannot exist.   E) Stars with a mass like the Sun will end up as a white dwarf star.   F) White dwarfs are less dense than red giants.   G) White dwarfs are the coolest main sequence stars.

Q: Choose the correct statements concerning spectral classes of stars. (Give ALL correct answers, i.e.,…

A: A) The K star or orange dwarf has spectrum dominated by hydrogen ionization lines not of ionized…

Q: Consider a close binary system composed of a white dwarf, a giant star, and an accretion disk. Which…

A: Given Data: Let us consider the given closed binary system composed of a white dwarf , a giant star…

Q: Two stars are in a closely orbiting binary system. The smaller star (a K-type main sequence star)…

A: The correct option. Following the mass transfer, which of the following is now true of the main…

Q: The star 58 Eridani is a feint but naked-eye star similar to the Sun. Suppose that you are observing…

A: To calculate the number of photons per second that arrive at the retina, we need to know the star's…

Q: Which statement accurately describes the scatterplot? y : OA. There are two distinct clusters. OB.…

A: option B is correct There is one outlier

Q: What are the approximate spectral type, temperature, absolute magnitude number, and luminosity of…

A: Required :  Spectral type, absolute magnitude, temperature and luminosity of star E.

Q: (d) You now know the sum of the two masses, and their ratio as well: two equations for two…

A: Given,

Q: Please answer within 90 minutes.

A: Part a. Part b. Part c.

Q: Suppose you observe a tight eclipsing binary with orbital period of 3 days, and radial velocity…

A: 1. Suppose you observe a tight eclipsing binary with orbital period of 3 days, and radial velocity…

Q: a) What is a binary star system? (b) describe briefly two methods for showing that a system is a…

A: (a) A binary star system is a system of two stars orbiting each other around a common center. Binary…

Q: White dwarfs have a temperature of 100×103 K. Calculate the maximum wavelength of a White dwarf.

A: A white dwarf is a stellar core remnant that is highly dense and made of electron-degenerate matter.…

Q: Consider a gas of pure ionized hydrogen. Calculate the central pressure of a Sun- like star which is…

A: Given, Temperature T = 2 × 108 K              Mass density D = 2 × 105 kg/m3             Pressure P…

Q: a) (Palen, et. al., 2nd, Problem 45) Rigel has a Hipparcos parallax of 0.00412 arcsec. Given Rigel…

A: Rigel and Betelgeuse are located in the constellation of Orion, which are about 864.3 and 642.5…

Q: 3. a) Explain how it is possible for the core of a red giant to contract at the same time that its…

A: a) The core of a red giant contracts due to depleted fuel, while nuclear fusion in surrounding…

Q: Based on what you learned about the source of stellar energy and how stars make energy, select all…

A: Solution: 1. Many stars make energy with the proton-proton cycle. True, Many, less massive stars…

Q: 1.  A planetary nebula has an angular diameter of 76 arc seconds and a distance of 5100 ly. What is…

A: 1.Small angle Formula:D=αd2.06×105where, D is the linear diameterα is the angular diameter=76 arc…

Q: like a black body with temperature 5800 K.  Use the Stefan-Boltzmann Law to calculate the Sun's…

A: Given: Sun's Radius (R) = 6.96 x 1010 cm  Stefan-Boltzmann Constant  (σ)=5.67 x 10-5 ergs/cm2 K4 s…

Q: Suppose a spectral line from an object in space was shifted from 5007.0 to 5100.0 Angstroms. What…

A: Given that: A spectral line from an object in space was shifted from 5007.0 to 5100.0 Angstroms.…

Q: . Imagine a giant sphere with a radius of 1 AU surrounding the Sun. What is the surface area of this…

A: "Since you have posted a question with multiple sub-parts, we will solve the first three subparts…

Q: From its spectral type, the surface temperature of a main sequence star is measured to be about…

A: Using the 1r2 rule method, we can find out the star's distance by measuring the intrinsic brightness…

Q: White Dwarf Size II. The white dwarf, Sirius B, contains 0.98 solar mass, and its density is about 2…

A: It is given that, M=0.98 solar mass=0.98×1.989×1030 kg=1.95×1030 kgρ=2×106 g/cm3=2×106×103…

Q: c) The star may be assumed to evolve with effective temperature, Teff, remaining constant. Show that…

A: To start, we'll use the equation for the luminosity of a star: where L is the luminosity, R is the…

Q: a) Sketch a generic HR diagram, including labels for the axes. (Take a picture or scan your work and…

A: a) HR diagram is,

Q: Which of the following is the least likely reason that astronomers consider supernova 1987A so…

A: Supernova 1987A is one of the most studied and significant supernovae in modern astronomy. It was a…

Q: Based on what you know about main-sequence stars, select all of the correct statements from the…

A: Required : Correct statements .

Q: 7. Let's characterize a typical neutron star. (a) Compute its luminosity in units of the solar…

A: The neutron star has a surface temperature of 106 K and a radius of 7 km One solar luminosity is…

Q: Indicate whether the following statements are true or false.   (Select T-True, F-False. If the…

A: Indicate whether the following statements are true or false A) White dwarfs are small dense objects…

Q: Match each characteristic below to the appropriate stellar end state. (Select W-White dwarf,…

A: “Since you have posted a question with multiple sub-parts, we will solve first three sub-parts for…

Q: Which statement is most logical?  a Once gravity overcomes thermal pressure, nebulae cloud turns…

A:

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.