UCCS Fall 2009
Astronomy Lab I PES 109 Final Review
Tuesday, 01-Dec-2009 11:44 PM
Celestial Mechanix
Age of the Universe: ~ 13.7 billion years + - 1%
Apparent Magnitudes of Stars: (negative # = brightest) & (positive # = dimmest)
Speed of light: 300,000 km/second
Earth's Angle of Precession: 23.5 degrees
Earth's Precession: ~ 26,000 years
Light Year (ly): Distance light travels in one Earth year.
Right Ascension (R.A.):
Declination (DEC):
Zenith:
Meridian:
Azimuth, (AZ) not a city in Arizona...
Nadir:
Altitude, (ALT):
Latitude, (LAT):
Longitude, (LON):
G P S for Colorado Springs, CO: 38.0 N & 104.0 W
Longitudinal lines are separated every: 15 degrees for the 24 Time zones on Earth
Prime Meridian: 0 Degrees Longitude
International Date Line: 180 Degrees Longitude
GMT: Greenwich Mean Time
UTC: Universal Time Coordinate
Constellations
Big Dipper is a group of stars called an: "asterism" which is part of the: Ursa Majoris Constellation
"Pointer Stars" in the Big Dipper:
“Guardian Stars” in the Ursa Minoris Constellation:
Present North Star: Polaris
Future North Star in: ~ 13,000 years: Vega (0.0 magnitude) in the Constellation of: Lyre
Number of Official Constellations: 88
Planet(s) observed during Fall Term 2009: ________________________
Alpha star in the Canis Majoris ConstellationCelestial Sphere
Celestial Equator
The EclipticRelationship between the Earth's Tilt the Constellations & the 4 Seasons
Series D Constellation Charts: Stars, Constellation Lines & Names
Gravity
Gravity:
Gives the universe its structure. A universal force that acts on all objects in the universe, so every particle is drawn toward every other particle by its pull.
Surface Gravity:
Measures the gravitational attraction at a planet's or star's surface " g ".
Law of Gravity:
Every mass exerts a force of attraction on every other mass. The strength of the force is directly proportional to the product of the masses divided by the square of their separation.
Newton's 3rd Law:
Also know as the Law of Action-Reaction. When 2 objects interact, they create equal and opposite forces on each other. The gravitational force of the Earth on the Sun is EXACTLY EQUAL to the gravitational force of the Sun on the Earth.
Light
Visible Spectrum: White light, the combination of all visible wavelengths (electro-magnetic spectrum) 400 nm to 700 nm approximately
Photons: Move in a straight line at "c" (speed of light), even if they are described as particles, photons behave as waves
The Eye
Human Eye: Sensitive to electro-magnetic radiation with wavelengths aprox 400 nm to 700 nm (nanometers)
The cornea and the lens of the eye, together focus the image on the retina which contains aprox. 125 million receptors (Rods & Cones), and aprox. a million optic nerve fibers.
Cones (R G B): Responsible for seeing in colour and in daylight.
Rods: Responsible for night vision and black white.
Rhodopsin: Sensitive chemical to light in the eye also known as: (visual purple)
Optics
Types of Lenses: Convex, & Concave
Telescopes Types: Reflector & Refractor
Telescope Focus Arrangements: Newtonian, & Schmidt Cassegrain
Eyepiece: short-focal-length type lens used to enlarge the images on a telescope
Binoculars: magnification number, & aperture of lens in mm
Sun
Solar Cycle: An 11 year cycle of sunspots & flare activity. Cycle averages 22 years since the polarity of the Sun's field reverses at the end of each 11 year cycle.
Corona: Sun's outer atmosphere
Sun will become a Red Giant in approximately 4 x 10^9 years
Sun's Magnitude:
Inner Terrestrial: Mercury, Venus, Earth & Mars
Outer Gas Giants (Jovian): Jupiter, Saturn, Uranus & Neptune
Spirit & Opportunity
Exobiology
Study of life elsewhere than on Earth
Astrobiology
Study of life anywhere in the universe, including past, present, & future life on Earth
N Intelligent = N stars x f planets x f life x f intelligence
Anthropic Principle
If the universe were a bit different than it is currently, we would not be here...
There is nothing to marvel about life on Earth...
Of course the conditions are right for life,
Otherwise there would not be any life to marvel about
SETI searches in the radio part of the electro-magnetic spectrum
From Wikipedia, the free encyclopedia
The Wow! signal was a strong narrowband radio signal detected by Dr. Jerry R. Ehman on August 15, 1977, while working on a SETI project at The Big Ear radio telescope of Ohio State University. The signal bore expected hallmarks of potential non-terrestrial and non-solar system origin. It lasted for 72 seconds, the full duration Big Ear observed it, but has not been detected again. Much attention has been focused on it in the media when talking about SETI results.
Amazed at how closely the signal matched the expected signature of an interstellar signal in the antenna used, Ehman circled the signal on the computer printout and wrote the comment "Wow!" on its side. This comment became the name of the signal.This region of the sky lies in the constellation Sagittarius, roughly 2.5 degrees south of the fifth-magnitude star group Chi Sagittarii.
