A nonluminous object, larger than a comet or asteroid, that orbits a star

 The distance light travels in one year

  Originated in Greek and Middle Eastern mythology, and the names are Latin. Even the modern constellations that was added later on to fill in the space between the ancient figures was given Latin names  

Senior body governing international professional astronomical activities worldwide. The IAU gathered together in 1928 to define and divide the sky into 88 constellations.

  A measure of light energy striking a square meter per second. The magnitude of a star is related directly to the flux of the recieved on Earth

  A scientific model of the sky to which stars appear to be attached. Because Earth rotates eastward, the celectial sphere appears to rotate westward on its axis 

  Represents a scaled down version of the actual object. but it is in a workable size.

  Are the pivots on which the appears to rotates, and they define the directions around the four horizons.

  North, South East, and West are four directional points of the horizon  

  Measured in degrees of Arc Minutes and Arc seconds

A degree of angular measurement, and not directly related to the true distance between the objects measured in

units; such as, Kilometers (km) or light-years (ly)  

A degree of angular measurement, and not directly related to the true distance between the objects measured in

units; such as, Kilometers (km) or light-years (ly)  

An angular distance across an object.

Happens becausse the gravitational forces of the moon and sun acting on the equatorial bulge of the spinning Earth which causes its axis to sweep around in a conical motion; For example, like the motion of a top's axis.

The Earth's axis precesses for a period of 26,000 years, and consequently the celestial poles and celestial equator moves slowly against the background of the stars.

The Earth rotates on its axis, which produces the cycle of night and day.

  When the Earth moves around the sun in an one year cycle. 

  The Earth orbits the sun, and the sun appears to move eastwardalong the eclipticthrough the constellations, completing a circuit of the sky in a year.

  Because the ecliptic is tipped 23.4° to the celestial equator, the sun spends half the year in the northern celestial hemisphere and half in the southern celestial hemisphere.

• Vernal equinox      (Mar. 20)
• Summer Solstice   (Jun. 21)
• Autumnal equinox (Sept. 21) 
• Winter Solstice      (Dec. 21) 

  Are dates that mark the beginning of Spring, Summer, Fall, and Winter.

  A point where a planet or comet is closest to the sun, and for Earth it means it is the closest to the sun in January. Perihelion has almost no effect on the seasons 

  The Earth is slightly further away from the sun, which happens in july. Aphehlion has almost no effect on the seasons 

  These are the first two stars to be seen in the west at sunset, and they are actually planets named: Mercury, and Venus

These are the first two stars to be seen in the west at sunset, and they are actually planets named: Mercury, and Venus

  The locations of the the sun and planets along the zodiac are diagrammed in a horoscope, which is the basis for the ancient pseudoscience known as astrology. 

  A chart showing the position of the sun, moon, planets and constellations at the time of a person's birth; used in astrology to attempt to read character or foretell the future. 

  A subject that claims to obey the rules of scientific reasoning but it does not.

  States the change in the shape of Earth's orbit, in its precession, and in its axial tilt can alter the planet's heat balance and cause the cycle of ice advances and retreats during an ice age.

  Evidence found in seafloor samples support the hypothysis, and it is widely accepted today.

  Scientists routinely test their own ideas by organizing theory and evidence. 

The study of the astronomy of ancient peoples.

  A belief that because the sphere was the most geometrical form, and the heavens must be made up of spheres in uniform rotation.

  Many ancient astronomers argued that the Earth could not be moving because they could see no parallax in the positions of the stars.

  The sun, moon, and stars were carried around Earth on rotating crystalline spheres. A belief that the Earth was the center of the universe.

  Earth near but not precisely at their center, and with the sun, moon and planets revolved in circles.   

  The occasional westward (backward) motion of the planets, and it was difficult for astronomers to explain

  The small circle followed by a planet in the Ptolemaic theory. The center of the epicycle follows a large circle (deferent) around Earth.

  In the Ptolmaic theory, the large circles around Earth along which the center of the epicycle moved. 

  The point off-center in the deferent from which the center of the epicycle appears to move uniformly.

  The sun was at the center of the universe, and the Earth on its axis and revolves around the sun.

  A specific statement about nature that needs further testing.

  Usually a general description of some aspects of nature that has been tested. 

  A fundamental principle in which scientists have great confidence

  The shift from geocentric paradigm to the heliocentric paradigm is an example of a scientific revolution.

  A closed curve enclosing two points (foci) such that the total distance from one focus to any point on the curve back to the other focus equals a constant.

 Planet's orbital period squared is proportional to the semimajor axis, α of its orbit cubed.

  A measure of the flattening of an ellipse. An ellipse e = 0 is circular. The closer to 1 that e becomes the more flatten the ellipse. 

  The satellites (moons) of jupiter that Galileo observed with the newly invented telescope.

 occured when a displaced object returned to its proper place.

  Was motion other than natural motion and had to be sustained by a force.

  The rate at which it accelerates 9.8 m/s² (32 ft/s²) at the Earth's surface.

  Change in velocity must be caused by a force. This is Newton's Second Law

  A rate of travel that specifies both speed and direction.

  The amount of matter in an object.

  A measure of a body's amount of moton is a combintaion of its velocity and mass. 

  The force of gravity is inversely proportionalto the square of the distance between the two objects.

  How gravity can act at a distance

  Follows an elliptical path. A circle is just a special of an ellipse with zero eccentricity.

  The moon and sun works against each other to produce the smallest tides at quarter moons.

  States that uniform (unaccelerated) motion is relative.

  States that a gravitational field is a curvature of space-time caused by the presence of a mass.

 Changing electric and magnetic fields that travels through space and transfer  energy from one place to another - for example, light, radio waves and the likes. 

  Visible light that is usually measured in nanometers or angstroms.

  An unit of measurement in the 0.000000001 meters. For visible light waves those are from range of 400 nm to 700 nm. 

An unit of measurement in the 0.0000000001 meters. For visible light waves those are from range of 4000 Å to 7000 Å. 

 The number of waves that pass a stationnary point in 1 second.

   F_em = C/λ

  A packet of light waves that can act as a particle or as a wave.

 E_photon = F/λ 

  A display of light sorted and viewed or recorded in order of wavelength or frequency.

  Electromagnetic waves with extremely short wavelength high frequency, and large photon energy. It is part of the electormagnetic spectrum that is in a range of  10^-12

  Electromagnetic radiation with short wavelength, high frequencies and high photon energies, between Gamma rays and Ultraviolet radiation on the electromagnetic spectrum.

  Electromagnetic radiation with wavelengths shorter than visible light but longer than X-rays. 

  Electromagnetic radiation with wavelengths intermediate between visible light and radio waves.

  Electromagnetic waves with wavelength, frequency, and photon energy intermediate between Infrared and radio waves.

  Electromagnetic wave with extremely long wavelength, low frequency, and small photon energy.

  Wavelength region in Earth's atmosphere is transparent - at visual, infrared, and radio wavelength.

Use a primary lens to bend the light and focus it into an image.

Used to bend the light and focus it into an image.

  A telescope that uses a concave mirrors to focus light into an image. Also, reflecting telescopes do not suffer from chromatic aberration. 

  Used to focus the light.

  Magnifies images produces by the primary lens or the mirror.

  Lenses and mirrors with short focal lengths must be strongly curved; therefor, are more expensive to grind to an accurate shape. 

  Causes the refracting telescopes to not bring all colors to the same focus, resulting in color fringes around the images.

  Partially corrects for color fringes around theimages, but such lenses are expensive and cannot be made much larger than about 1 m (40 in.) in diameter.

  Are reflecting telescopes because they are easier to build and less less expensive than refracting telescopes of the same diameter. 

  A telescope that gathers and focus electromagnetic energy with microwave and radio wavelengths.  

  Refers to the ability of a telescope to collect light; proportional to the area of the telescope objective to lens or mirror

  Refers to the ability of a telescope to reveal fine details; depends on the diameter of the telescope objective.

  Blurred fringes surrounding any image caused by properties of light. Because of this, no image detail smaller than the fringes can be seen

   Ability to make an object look bigger; this is less important to the telescope power because it is not a property of the telescope, itself, but by changing the eye-piece can increase or decrease the magnification power of a telescope. 

  Term that astronemrs use because the turbulence in the Earth's atmosphere blurs the image of an astronomical object. 

  Cities, towns, rural areas can cause light pollution which makes observing the stars and planets impossible for astronomers; therefor, the build observatories in remote location and high on mountain tops. 

  The point at which the objective mirror forms an image in a reflecting telescope.

   In a reflecting telescope, the mirror that reflects the light to a point for easy observation. 

  The optical design for a reflecting telescope in which the secondary mirror reflects light back down the tube through a hole in the center of the objective mirror. 

  The focal arrangement of the reflecting telescope in which a diagnal mirror reflects light out the side of the tube telescope for easier access.  

  The optical design of a reflecting telescope in a which thin correcting lens is placed at the top of the Cassegrain telescope.

  Helps keep the telescope pointing at the celestial object as the Earth rotates.

  A telescope mounting that allows motion parallel to and perpendicular to the celestial equator.

in an equatorial telescope mounting, the axis that is parallel to Earth's axis of rotation. 

  A telescope mounting that is capable of moving massive telescope by computer control parallel to and perpendicular to the horizon.

  Used with very large telescopes (VLT). the active optics use thin but flexible mirrors or composed of segments with the aid of computers to move.

  Were used in the past by astronomers to record images.

 Were ued to precisely measure the brightness of celestial objects.

The CCDs have replaced the ancient photographic plates in most applications today.

  The CCD Array detectors have replaced the anciant photometers in most applications today.

 Electronic detectors have the advantage,  data from them are automatically digitized in numerical formats, and the digitized information can be easily recorded and manipulated.   

  Astronomical images are produced by digital form that has been computer-enhanced to bring out subtle details.

Another name for Representational-color iamges.

  A device that seperates light by wavelengths to produce a spectrum.

  A piece of material in which numerous microscopic parallel lines are inscribed; light encountering a grating dispersed in form a spectrum.

Produced by atoms and molecules in the object being studied.

 Containing lines of of known wavelength allow astronomers to measure wavelength in a spectra of astronomical objects.

  A techniques involve measuring seeing distortions by caused by turbulence in the Earth's atmosphere and partially canceling out those distortions by rapidly altering the telescope's optic components.

  It is high in Earth's atmosphere that can be monitored by an adaptive optic system.

  Refers the observing technique of connecting two or more seperate telescopes combined to produce virtual telescope with the resolution of much-larger-diameter telescope.

  They are not electromagnetic radiation; they are subatomic particles such as electrons and photons travelingf at nearly the speed of light, arriving from mostly unknown cosmic sources.

  A field of study that interprets astronomical observations in terms of physics theory and labatory experiments in order to understand the composition, internal processes, and histiory of celestial objects.

Is positive charged atom and is housed in the nucleus with its brother, Neutron.

  Is neutral atom and is housed in the nucleus with its Sister, Photons.

  The number of protons in an atom determines which element it is. An Atom of the same elements (same number of protons) with different number of neutrons are called isotopes.

Happens when an atom has lost or gained an electron.

  This is abbreviated form for ionized. Happens when an atom has lost or gained an electron.

Forms when two or more atoms joined together.

Happens when the electrons in an atom attracted to the nucleus.  

The binding energy that holds electrons in an atom is limited to certain energies and that means the electrons may occupy only certain permitted orbits.

Levels that the electrons are allowed to occupy.

  The size of electron's orbit depends on its energy, so the orbits can be thought of as energy levels.

The lowest possible energy level.

One in which an electron is raised to a higher orbit by a collision between atoms or the absorption of a photon of the proper energy wavelength.

The agitation amoung the atoms and molecules of an object.

The flow of thermal energy.

   A measure of the velocity of random motion among the atoms or molecules in a material.  

The scale used to measured in celcius (centigrade) degree of temperature above absolute zero.

The point where no heat can be removed from the system.

  Collision among the particles in an object accelerated electrons and cause the emission of blackbody radiation.

  The hotter an object is the more total energy it radiates

The shorter is λ_max allows astronomers to estimate the temperatures of stars form their colors.