Which statements are true about all white dwarfs? Select the two correct answers.

Question

(1 point)
Responses

All white dwarfs are classified in spectral class B.
All white dwarfs are classified in spectral class B.

All white dwarfs have absolute magnitudes around 10.
All white dwarfs have absolute magnitudes around 10.

All white dwarfs have luminosities of around 10–2.
All white dwarfs have luminosities of around 10 –2 .

All white dwarfs have temperatures around 10,000 K.
All white dwarfs have temperatures around 10,000 K.
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Answer 1

The two correct statements about all white dwarfs are:

1. All white dwarfs have temperatures around 10,000 K.
2. All white dwarfs have luminosities of around 10⁻².

White dwarfs typically have high surface temperatures, often in the tens of thousands of Kelvin range, and their luminosities are generally lower compared to main sequence stars, typically around 0.01 times that of the Sun (or 10⁻² times).

The other statements are not accurate:

• White dwarfs are not classified in spectral class B; they usually fall into spectral classes such as DA, DB, or other classifications based on their composition and characteristics.
• Their absolute magnitudes can vary widely, but they are often brighter than an absolute magnitude of 10.

Answer 2

How is the sun classified on an Hertzsprung-Russell Diagram?(1 point)
Responses

as a white dwarf star
as a white dwarf star

as a giant star
as a giant star

as a supergiant star
as a supergiant star

as a main sequence sta

Answer 3

The Sun is classified on a Hertzsprung-Russell Diagram as a main sequence star.

Main sequence stars are those that are in the stable phase of their lifecycle, where they fuse hydrogen into helium in their cores, which includes stars like the Sun.

Answer 4

Which of these phrases describes the sun?(1 point)
Responses

Class G yellow star
Class G yellow star

Class A white star
Class A white star

Class M red star
Class M red star

Class O blue star

Answer 5

The phrase that describes the Sun is Class G yellow star.

The Sun is classified as a G-type main-sequence star (G dwarf), and it emits a yellowish color due to its surface temperature.

Answer 6

Which of these properties is the best measure of a star's brightness?(1 point)
Responses

apparent magnitude
apparent magnitude

age
age

size
size

absolute magnitude

Answer 7

The best measure of a star's brightness is absolute magnitude.

Absolute magnitude refers to the intrinsic brightness of a star, defined as the brightness it would have if it were located at a standard distance of 10 parsecs (about 32.6 light-years) from Earth. Apparent magnitude, on the other hand, measures how bright a star appears from Earth, which can be affected by distance and interstellar material.