Ecliptic
Declination
(astronomy) the angular distance to a point on a celestial object measured north or south from the celestial equator
What factors determine the luminosity of a Star?
Surface Temperature and Size. Hotter=Brighter Cooler=Dimmer
What is the main sequence?
A continuous and distinctive band of stars that appears on plots of stellar color versus brightness.
What is the Finder scope used for?
A finder scope is a little telescope that mounts on your main telescope. It has a much wider field of view. It is used to help find objects in the sky.
Celestial Equator
A great circle on the imaginary celestial sphere, in the same plane as the Earth's equator. In other words, it is a projection of the terrestrial equator out into space. As a result of the Earth's axial tilt, the celestial equator is inclined by 23.4° with respect to the ecliptic plane.
What is the focal length of a telescope?
A measure of how strongly the system converges or diverges light. The distance over which initially collimated rays are brought to a focus. A system with a shorter focal length has greater optical power than one with a long focal length; that is, it bends the rays more strongly, bringing them to a focus in a shorter distance.
Celestial Meridian
An imaginary great circle on the celestial sphere. It passes through the north point on the horizon, through the celestial pole, up to the zenith, through the south point on the horizon, and through the nadir, and is perpendicular to the local horizon
Zenith
An imaginary point directly "above" a particular location, on the imaginary celestial sphere
Constellations
An internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky.
Nebula
An interstellar cloud of dust, hydrogen, helium and other ionized gases.
Horizon
Apparent line that separates earth from sky
Emission Spectrum
Bright lines on black background. When electrons in an atom get excited, they jump to higher energy levels. In order for them to do this, they must absorb energy. However, when electrons "calm down", they drop back down and thus release emit energy in the form of photons. This emission of energy is the light that we see. The color of the light we see depends on the distance the electron drops--the longer the drop, the higher the energy.
Continuous Spectrum
Complete Rainbow of colors on spectrum. Found in most stars.
Absorption Spectrum
Dark lines on rainbow
Movement of the Sun and Moon over time
Everyday the stars, Moon and Sun move E to W in the sky. Over the course of the month, the noon moves W to E in the sky. Over the course of a year the Sun moves W to E in sky.
Spectral class of the sun?
G2
What is the relationship between magnification and Field of View?
Inverse. As magnification increases, the field of view decreases.
How many hours of R.A. must be added to the Sun's R.A. to correspond with each moon phase?
New Moon = +0. First Quarter = +6. Full Moon = +12. Third Quarter = +18.
Phases of the moon
New Moon, Waxing Crescent, First Quarter, Waxing Gibbous, Full Moon, Waning Gibbous, Third Quarter, Waning Gibbous, New Moon
Vernal Equinox
Occurs when the Sun is directly overhead at the equator and results in day and night of equal length for both northern and southern hemispheres. Earth's axis is inclined neither away from nor towards the Sun, the center of the Sun being in the same plane as the Earth's equator.
Right Ascension
One of the two direction coordinates of a point on the celestial sphere in the equatorial coordinate system, measured eastward along the celestial equator from the vernal equinox to the hour circle of the point in question.
Ecliptic
Path of the Sun on the celestial sphere as seen from Earth.
What determines spectral classification?
Temperature. OBAFGKM Hot to Cool, Blue to Red
Luminosity
The amount of electromagnetic energy a body radiates per unit of time
Magnitude
The logarithmic measure of the brightness of an object.
What is Aperture?
The most important feature of any telescope, determines how much light the telescope can gather and bring to focus. The greater diameter of its clear aperture allows more fine detail to be seen. As the aperture of the telescope increases, fainter stars and more detail can be seen. Clesetron 8 telescope has a clear aperture of 8 inches.
What is measured on the Hertzsprung Russell Diagram?
The relationship between the stars' absolute magnitudes or luminosities versus their spectral types or classifications and effective temperatures.
What are the setting circles used for?
To find astronomical objects in the sky by their equatorial coordinates
Length of lunar month: New moon-New moon
~28 days