Conceptual Questions 1 Flashcards
Spectrum of the hydrogen Atom: how do the Balmer and Lyman line series form?
The Lyman line series forms when an excited electron shifts from higher level to the n=1 energy level.
The Balmer Line series forms when an excited electron reaches the n=2 energy level.
The spectral lines emerge from emission spectra of the hydrogen atom.
What is the Doppler effect, give one example for its use in astronomy?
A shift in the frequency of waves emitted from an object moving relative to the observer.
In astronomy it can be used to measure the radial velocities of distant objects.
How do we measure stellar masses?
we can measure the masses of stars in a binary star system using newton’s verions of kepler’s third law. This is if we know the orbital period and separation of the two stars.
What is an ellipse?
An ellipse is a conic shape with two interior foci, a center, a major axis and a minor axis. Also it has an eccentricity in between 0 and 1.
What is stellar parallax and for what is it used in astronomy?
the apparent displacement of an object because of a change in the observers point of view. It is used to find the distance between the Earth and celestial objects.
What is apparent magnitude? How brighter is a a star with magnitude 6 compared to a star with magnitude 1?
Apparent magnitude is a measuring system for the brightness of celestial objects. It is logarithmic
and smaller numbers are brighter. A magnitude 6 star is 100 times fainter than a magnitude 1 star.
What is absolute magnitude?
It is a measure of the brightness of a star or other object.
It is the apparent magnitude of a celestial object if it were located a distance of 10 parsecs from the Earth.
What is Kepler’s 1st law?
Each planet’s orbit about the Sun is an ellipse.
The Sun’s center is located at one focus of the orbital ellipse.
What is Kepler’s 2nd law?
A line between the Sun and the planet sweeps equal areas in equal times. Therefore the speed of a planet increases as it nears the Sun and decreases as it moves away.
What is Kepler’s 3rd law?
The squares of the orbital periods of the planets are directly proportional to the cubes of the semi major axes of their orbits.
