Astr 3- Hw 8

identify a white dwarf

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  Barnard’s star

•  

  Betelgeuse

•  

  40 Eridani B

•  

  Polaris

Among these stars, the one with the longest lifetime

•  

  Polaris

•  

  Aldebaran B

•  

  Betelgeuse

•  

  Sun

An object that is burning deuterium in its core, but is not hot enough to burn hydrogen is a - 

•  

  super earth

•  

  brown dwarf

•  

  red giant star

•  

  white dwarf star

Helium core-burning star

•  

  Sirius B

•  

  Capella A

•  

  Barnard’s star

•  

  Alnilam

The main sequence lifetime for a G star is approximately — years.

•  

  1 billion

•  

  10 billion

•  

  10 million

•  

  1 million

A planetary nebula is —

•  

  the cloud of gas blown off by protostar perpendicular to the disk

•  

  a collapsing gas cloud out of which planets will form

•  

  a gas cloud which is accreted by stars to form red giants

•  

  an expanding gas cloud that was ejected by a red giant star

A white dwarf has a radius the size of

•  

  a large city

•  

  the orbit of Mars

•  

  the sun

•  

  Earth

What is the approximate surface temperature of Capella A?

•  

  20,000 K

•  

  10,000 K

•  

  6000 K

•  

  1000 K

Which star is a red giant?

• Betelgeuse

• Barnard’s star

• Spica A

•  Canopus

The H-R diagram is a plot of—

•  

  luminosity vs. temperature.

•  

  luminosity vs. magnitude.

•  

  luminosity vs. radius.

•  

  mass vs. temperature.