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White Dwarfs and Their Characteristics

Description: White Dwarfs and Their Characteristics
Number of Questions: 14
Created by:
Tags: astrophysics stellar evolution white dwarfs
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What is the final stage in the evolution of a low-mass star?

  1. Red Giant

  2. Supernova

  3. Black Hole

  4. White Dwarf


Correct Option: D
Explanation:

Low-mass stars end their lives as white dwarfs, which are dense, compact remnants of stars that have exhausted their nuclear fuel.

What is the typical mass range of a white dwarf?

  1. 0.1 - 0.5 solar masses

  2. 0.5 - 1.0 solar masses

  3. 1.0 - 1.5 solar masses

  4. 1.5 - 2.0 solar masses


Correct Option: B
Explanation:

White dwarfs typically have masses between 0.5 and 1.0 solar masses.

What is the radius of a white dwarf compared to that of the Sun?

  1. Similar to the Sun

  2. 10 times smaller than the Sun

  3. 100 times smaller than the Sun

  4. 1000 times smaller than the Sun


Correct Option: C
Explanation:

White dwarfs are extremely dense, with radii that are typically about 100 times smaller than that of the Sun.

What is the surface temperature of a white dwarf?

  1. Below 10,000 K

  2. 10,000 - 20,000 K

  3. 20,000 - 30,000 K

  4. Above 30,000 K


Correct Option: D
Explanation:

White dwarfs have surface temperatures that can reach tens of thousands of Kelvin, making them very hot objects.

What is the primary energy source of a white dwarf?

  1. Nuclear fusion

  2. Gravitational contraction

  3. Residual heat

  4. Accretion from a companion star


Correct Option: C
Explanation:

White dwarfs no longer undergo nuclear fusion and rely on residual heat from their previous stages of evolution.

What is the fate of a white dwarf in the long term?

  1. It will cool and become a black dwarf

  2. It will explode as a supernova

  3. It will merge with another white dwarf

  4. It will be engulfed by its companion star


Correct Option: A
Explanation:

Over time, white dwarfs will gradually cool and eventually become black dwarfs, which are hypothetical objects that have cooled to very low temperatures.

Which famous white dwarf is located in the Sirius binary system?

  1. Proxima Centauri

  2. Sirius A

  3. Sirius B

  4. Betelgeuse


Correct Option: C
Explanation:

Sirius B, also known as the Pup, is a white dwarf companion to the bright star Sirius A in the Canis Major constellation.

What is the Chandrasekhar limit for a white dwarf?

  1. 1.4 solar masses

  2. 2.0 solar masses

  3. 2.5 solar masses

  4. 3.0 solar masses


Correct Option: A
Explanation:

The Chandrasekhar limit is the maximum mass that a white dwarf can support without collapsing under its own gravity and becoming a neutron star.

What is the process by which a white dwarf can accrete material from a companion star?

  1. Roche lobe overflow

  2. Tidal disruption

  3. Gravitational lensing

  4. Supernovae


Correct Option: A
Explanation:

Roche lobe overflow occurs when a star transfers mass to its companion star through gravitational interactions.

What is the name of the white dwarf that is the remnant of the first supernova observed by astronomers?

  1. SN 1987A

  2. SN 1054

  3. SN 1572

  4. SN 1604


Correct Option: B
Explanation:

SN 1054, also known as the Crab Nebula, is the remnant of a supernova that occurred in 1054 AD and left behind a white dwarf.

Which white dwarf is known for its rapid rotation and has been used to test theories of general relativity?

  1. PSR J1719-1438

  2. PSR J0740+6620

  3. PSR B1919+21

  4. PSR B1509-58


Correct Option: A
Explanation:

PSR J1719-1438 is a rapidly rotating white dwarf that has been used to study the effects of general relativity on compact objects.

What is the name of the white dwarf that was discovered to have a massive planetary companion?

  1. WD 1145+017

  2. WD 0806-661

  3. WD 1856+534

  4. WD 0137-349


Correct Option: A
Explanation:

WD 1145+017 is a white dwarf that was found to have a Jupiter-mass planet orbiting it, challenging traditional theories of planet formation.

Which white dwarf is known for its unusual composition, containing a high abundance of carbon and oxygen?

  1. WD 0501-027

  2. WD 0346+246

  3. WD 1202-024

  4. WD 1337-333


Correct Option: A
Explanation:

WD 0501-027 is a carbon-oxygen white dwarf that has been studied extensively for its unique composition.

What is the name of the white dwarf that is the remnant of a Type Ia supernova?

  1. SN 1987A

  2. SN 1054

  3. SN 1572

  4. SN 1604


Correct Option: A
Explanation:

SN 1987A was a Type Ia supernova that occurred in the Large Magellanic Cloud in 1987 and left behind a white dwarf.

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