Star Properties Part 2

What is meant by the term luminosity?

• Luminosity is the amount of energy generated in the star as electromagnetic radiation.

• Luminosity is how bright a star seems to an observer far away.

• Luminosity is the color at which a star burns.

• Luminosity is the determinant of whether a star is approaching an observer or receding,

How do we calculate the luminosity of the Sun?

• use the inverse square law

• use Einstein's law of mass -energy conversion

• use the quadratic equation

• use the accekeration formula a = f/m

At the Earth's surface, how much energy do we receive from the Sun?

• 1,400,000 ergs/square cm/second

• 9.8 meters/second2

• 3.1416 joules/second

• 1x10^3 kilowatts/minute

Stellar diameters can be measured for some nearby giant and supergiant stars by using a technique called stellar:

• triangulation.

• calculus.

• binomial quadratics.

• interferometry.

What is the unit for measuring the linear diameters of stars?

• miles

• millions of kilometers

• light years

• solar radii

Which of the following is but the most reliable method for measuring distances to stars?

• algebraic formulation

• geometric parallel

• trigonometric parallax

• applying Newton's second law

Which of the following is the best description of the parallax effect?

• The parallax effect is the square root of the diameter of the star.

• The parallax effect is the apparent motion of a nearby object compared to distance background objects because the change in viewing angle.

• The parallax effect is calculated by dividing the star's mass by its volume.

• The parallax effect is the distance to a star divided by its intrinsic luminosity.

The apparent annual motion of the stars compared to background stars that is really a reflection of the Earth's motion around the Sun is referred to as:

• perigee.

• apogee.

• progression.

• parallax.

What is the angle between the Earth at one time of year, and the Earth six months later, as measured from a nearby star, referred to as?

• the parallax angle

• the angle of recession

• the parallel cosine angle

• the critical angle

Astronomers use ____________ to find the distance from the Earth to a star.

• luminosity

• the parallax angle

• apparent brightness

• light years