Chapter 30: Stars Flashcards
Describe the basic properties of the sun
- largest object in the solar system
- contains more than 99 percent of all the mass in the universe
- the density in the center of the sun is about 13x that of lead
- much of the sun is gaseous
What is the photosphere
the lowest layer of the sun’s atmosphere. Approximately 400 km in thickness. This is the visible surface of the sun, it emits the most light. 5 800K
what is the chromosphere
above the photosphere, approximately 2500km in thickness. 30 000K. visible during solar eclipse when photosphere is blocked
What is the corona
The top layer of the sun’s atmosphere. extends several million km into space. 1-2million K
What is Solar wind
gas flowing out from the corona at high speeds.
How is the sun’s magnetic field and its activity cycle regulated
sun spots regulate the magnetic field by sun spots which poke through where there is lots of magnetism as hot gasses are prevented from reaching the surface . It takes 11.4 years for the solar activity cycle, Min number of spots then increases to max and resets when the poles reverse.
prominence
arc of gas ejected from the chromophere
solar flares
violent eruptions of particles and radiation from the surface of the sun
what is a constellation
groups of stars the ancient people named after animals, mythical people or everyday objects
binary star
two stars that are gravitationally bound to each other and orbit a common center of mass
parallax
an apparent shift in position caused by the motion of the observer
Magnitude vs. apparent magnitude vs. absolute magnitude
- how bright it appears
- number system. a difference in 5 magnitudes corresponds to a 100 factor in brightness
- a brightness an object would have if it was placed at 10 pc.
luminosity
the energy output from a star per second
luminosity
the energy output from a star per second
How are stars classified
O B A F G K M and then further divided in a number series of one through nine.
O stars are the hottest and M stars the coolest
