Stars 1
Which is brighter: a star with magnitude +1, or a star with a magnitude -1?
-1! Lower = brighter
Give one fact about white dwarf stars.
2nd most commonly observed, dim and small, extremely dense matter
What is a variable star?
A star that varies in its brightness.
Which type of star acts like an inflating and deflating balloon?
Pulsating variables.
Name the 4 main groups of stars.
White dwarfs, main sequence, red giants, supergiants
90% of the stars astronomers have studied fall into this category.
Main sequence stars.
What are the 3 types of variable stars?
Pulsating variables, novas, and supernovas.
What are binary stars?
2 stars that orbit each other, and sometimes eclipse. They mimic Variable Stars, but are not.
How are temperature and color of stars related?
The hotter the star, the shorter the wavelength.
What kind of star is Magnitude -8, Spectral A? And how common is it in the universe?
Supergiant! Super rare.
What does the word nova actually mean in Latin?
New star
What is the most common type of variable star?
Pulsating variables.
Main sequence, and gives off red/orange wavelengths.
What happens in the core of a main sequence star?
Exactly what happens in the sun's core. Large amount of energy produced from nuclear fusion of hydrogen into helium. The more massive it is, the brighter it is.
Explain why novas vary in brightness.
A fraction of mass is given off in an explosion, which causes a temporary surge in brightness.
What is a nebula?
A cloud of bright gases left over from a supernova, made up of the debris of its explosion.
Who is Henrietta Leavitt?
An American astronomer who studied enormous number of Cepheid variable stars and discovered relationship between pulsation period and magnitude.
What takes place in the core of a red giant?
Nuclear fusion with 3 He atoms fusing to make carbon atoms.
Why are Cepheid stars helpful to astronomers?
They can be used to measure the distance of a star, using the Apparent Magnitude Method.
What is the parallax method?
Observing a distant star at two different times of the year, and relating the angles using geometry.