Astronomy and Cosmology: Standard candles

Which of the following is NOT a unit to measure distances in astronomy?

• pc

• Mpc

• ly

• F

What is meant by luminosity of a star?

• The total energy of radiation emitted by a star.

• The total power of radiation emitted by a star.

• The intensity per unit area emitted by a star.

• The total power per unit area emitted by a star.

What is the unit of luminosity?

• W

• J

• W m^-2

• J m^-2

Define radiant flux intensity.

• The radiant power passing normally through a surface per unit area.

• The total power of radiation emitted by a star.

• Astronomical object of known luminosity.

• The distance travelled by electromagnetic waves throug vacuum in one year.

What is the unit of radiant flux intensity?

• J

• N m

• pc

• W m^-2

What is the term used to describe an astronomical object that has known luminosity?

• cepheid variable

• standard candle

• blackbody

• supernova