Chapter 1 & 2

The star has a right ascension RA) =6 hr 43 m and Declination (Dec) = -16 39'.

The altitude of the NCP is the same as your latitude.

Vega

Vega

Alpha Centauri

Sirius

It represents an extension of Earth's equator onto the celestial sphere.

latitude = 60 degrees South

Stars are circumpolar if they have a declination less than + 57 degrees.

latitude 40 degrees North, longitude 30 degrees West

depends on the observer's latitude

They are coordinates on the celestial sphere, with declination telling us the angular distance of an object from the celestial equator and right ascension telling us how far around the celestial sphere an object is located from the vernal equinox.

Deneb

Alpha Centauri

Stars are circumpolar if they have a declination of less than +56 degrees.

south of the celestial equator

They were all used by ancient people for astronomical observations.

88

because of the location of Earth in its orbit.

a half circle extending from your horizon due north, through your zenith, to your horizon due south.

zenith

The celestial sphere is just another name for our universe

on the northern horizon

the stars in the constellations are so far away

the Sun's apparent path along the celestial sphere

The band that extends about 8 degrees either side of the ecliptic

Thy always remain above your horizon

a region of the sky, as seen from earth

latitude and longitude

always remains above your horizon (never sets)

spinning neutron star

The angular distance between those 2 bright stars in the sky is about 3 meters.

120

distant, energetic, puzzling

meteorite

huge clouds of interstellar gas

a region in space where mass produces a gravity field so intense that neither matter nor light itself can escape

5 billion years old

about 14 billion years ago

supernovae

decreasing

* 4 light years * 1 parsec 10 trillion miles 1000 AU

4.6 (5) billion years old

an explanation for a phenomenon that makes a prediction

the idea that scientists should prefer the simpler of two models that agree equally well with observations

a generally well-established scientific theory or set of theories

predict human events

humankind's beginnings

theory

may change

physics

fundamentally different from each other

a synthesis of a large body of well-tested knowledge

a few thousand

several thousand years

1,000 millions

the average distance between the earth and the sun

100 billion

about 670 million miles

hundreds of billion

1000 billions *1 x 10^3* 9 trillions 1,000,000,000,000 They are equal.

1 light year 1 AU *7 trillion miles* 100 million miles

The one that is the farthest away

The universe is about 14 billion light years old

A fake or false science that makes claims based on little or no scientific evidence.

2nd generation star

150,000,000 km/1 AU/ 93 million miles/

186,000 miles per second or 300,000 kilometers per second

a unit of measurement used to describe distances between celestial objects, equal to 3.26 light years

a measure of the angle formed by extending imaginary lines outward from our eyes to span an object

the angle that appears to separate a pair of objects in the sky

Unit of angular distance that is equal to a 60th of a degree

1/3600 of a degree, 1/60 arcminute

An arc that for the most part follows 180° longitude, although it deviates in several places to avoid dividing land areas. When you cross the International Date Line heading east (toward America), the clock moves back 24 hours, or one entire day. When you go west (toward Asia), the calendar moves ahead one day.

about 33 degrees North

the angle formed between a line perpendicular to the earth's surface and the position of the sun in the sky

angle between horizon and sun's position above horizon

star at the zenith of the North Pole

the most familiar group of stars in the southern sky

A term describing a star that neither rises nor sets but appears to rotate around one of the celestial poles.

the study of the movements and relative positions of celestial bodies interpreted as having an influence on human affairs and the natural world.

the study of stars and planets

arbitrary regions that cover the entire sky, which astronomers have named

stars that can be seen at all times of the year and all times of night.

Pair of quantities right ascension and declination similar to longitude and latitude on Earth, used to pinpoint locations of objects on the celestial sphere.

150 million km/ 93 million miles

6 trillion miles

Away from the earth

The process by which two or more small nuclei fuse to make a bigger nucleus

This is the explosion of a star, when this happens the star becomes extremely bright for a while

The velocity an object must reach to fly beyond a planet's or moon's gravitational pull.

90 thousand trillion Jules

the equinox that occurs on March 21 or 22 in the Northern Hemisphere (longer days)

June 21, when the sun is at its northernmost point (shorter days)

Earth's rotation axis is tilted neither toward nor away from the Sun; occurs on September 21st (longer nights)

December 22, when the sun is at its southernmost point (shorter days)

the line at which the sky and Earth appear to meet

An arc drawn on a map between the North and South poles.