Time and Diurnal Motion 1a. The Earth Is Flat
... • Anaximander (580 BC) invents idea of celestial sphere. (?) • Eudoxus (360 BC) makes early map of constellations • Hipparchus (130 BC) made a star catalog of 850 stars with some sort of coordinates • Claudius Ptolemy (150 A.D.?): The first really accurate map, 48 constellations, 1025 stars with mea ...
... • Anaximander (580 BC) invents idea of celestial sphere. (?) • Eudoxus (360 BC) makes early map of constellations • Hipparchus (130 BC) made a star catalog of 850 stars with some sort of coordinates • Claudius Ptolemy (150 A.D.?): The first really accurate map, 48 constellations, 1025 stars with mea ...
1 1. The Solar System
... Celestial Sphere: The celestial sphere is an imaginary shell of infinite radius, centered on the observer. This concept is useful for determining positions in the sky. Zenith: This is the point in the sky directly above the observer. Celestial Poles: As the Earth rotates, the sky appears to rotate a ...
... Celestial Sphere: The celestial sphere is an imaginary shell of infinite radius, centered on the observer. This concept is useful for determining positions in the sky. Zenith: This is the point in the sky directly above the observer. Celestial Poles: As the Earth rotates, the sky appears to rotate a ...
EQUINOCTIAL vLOBE ·
... The poles of the axes of motion are connected by strong .hrass wires. This globe is provided with an equator, tropics, arctic and antarctic circles of brass, and an hour circle, which may be fixed, or removed, as occasion may require," brass meridian. ...
... The poles of the axes of motion are connected by strong .hrass wires. This globe is provided with an equator, tropics, arctic and antarctic circles of brass, and an hour circle, which may be fixed, or removed, as occasion may require," brass meridian. ...
The celestial sphere
... Azimuth is angle from N cardinal point going eastwards (in S hemisphere from S cardinal point going eastwards) round horizon to where great circle through zenith and point cuts horizon (0 A 360). ...
... Azimuth is angle from N cardinal point going eastwards (in S hemisphere from S cardinal point going eastwards) round horizon to where great circle through zenith and point cuts horizon (0 A 360). ...
Lecture 2
... and Celestial Equator Hint #1: how many degrees long is the orange arc, the distance from the celestial equator to the horizon? Start by asking what the length of the pink arc is? 36 degrees Now what is the sum of the pink plus orange arcs? (What is the distance in degrees from zenith to horizon?) 9 ...
... and Celestial Equator Hint #1: how many degrees long is the orange arc, the distance from the celestial equator to the horizon? Start by asking what the length of the pink arc is? 36 degrees Now what is the sum of the pink plus orange arcs? (What is the distance in degrees from zenith to horizon?) 9 ...
Basic principles of celestial navigation
... convenient to take the longitude westward of the prime meridian to be between 0° and !180°. The longitude of P also can be specified by the plane angle in the equatorial plane whose vertex is at O with one radial line through the point at which the meridian through P intersects the equatorial plane ...
... convenient to take the longitude westward of the prime meridian to be between 0° and !180°. The longitude of P also can be specified by the plane angle in the equatorial plane whose vertex is at O with one radial line through the point at which the meridian through P intersects the equatorial plane ...
Basic principles of celestial navigation
... convenient to take the longitude westward of the prime meridian to be between 0° and !180°. The longitude of P also can be specified by the plane angle in the equatorial plane whose vertex is at O with one radial line through the point at which the meridian through P intersects the equatorial plane ...
... convenient to take the longitude westward of the prime meridian to be between 0° and !180°. The longitude of P also can be specified by the plane angle in the equatorial plane whose vertex is at O with one radial line through the point at which the meridian through P intersects the equatorial plane ...
SU3150-Astronomy - Michigan Technological University
... A spherical triangle is formed by the intersection of three great circle arcs This means that the sides of a spherical triangle are NOT straight lines but arcs of circles The length of a side of a spherical triangle is the length of the spherical arc Recall that the length of a spherical arc is equa ...
... A spherical triangle is formed by the intersection of three great circle arcs This means that the sides of a spherical triangle are NOT straight lines but arcs of circles The length of a side of a spherical triangle is the length of the spherical arc Recall that the length of a spherical arc is equa ...
Lecture 2
... parallax could mean one of two things: 1. Stars are so far away that stellar parallax is too small to notice with the naked eye 2. Earth does not orbit Sun; it is the center of the universe With rare exceptions such as Aristarchus, the Greeks rejected the correct explanation (1) because they did not ...
... parallax could mean one of two things: 1. Stars are so far away that stellar parallax is too small to notice with the naked eye 2. Earth does not orbit Sun; it is the center of the universe With rare exceptions such as Aristarchus, the Greeks rejected the correct explanation (1) because they did not ...
Trivia Question of the Day
... of daylight - Sun directly over Tropic of Capricorn (23.5°S) Equal (12) hours of day and night - Sun directly over Equator (0°) ...
... of daylight - Sun directly over Tropic of Capricorn (23.5°S) Equal (12) hours of day and night - Sun directly over Equator (0°) ...
Obliquity and precession of the equinoxes The angle ε between the
... By the end of March, local noon arrives at about 11:53am. This effect reverses as the Sun approaches aphelion, but then after aphelion, the cumulative effect of consecutive long solar days causes the transit to occur later and later by the clock so that by the end of September, local noon occurs at ...
... By the end of March, local noon arrives at about 11:53am. This effect reverses as the Sun approaches aphelion, but then after aphelion, the cumulative effect of consecutive long solar days causes the transit to occur later and later by the clock so that by the end of September, local noon occurs at ...
Solutions to the 1 st Astronomy Exam
... 11. The date is April 15 and the Sun is rising 27 away from due east. What is the Sun’s rising azimuth? The tricky part of this question is knowing whether the Sun rose 27 away from due east towards the north or towards the south? To answer which side of due East the Sun rose you compare the date ...
... 11. The date is April 15 and the Sun is rising 27 away from due east. What is the Sun’s rising azimuth? The tricky part of this question is knowing whether the Sun rose 27 away from due east towards the north or towards the south? To answer which side of due East the Sun rose you compare the date ...
celestial sphere
... star chart mounted in such a fashion that it can be oriented to represent the true aspect of the sky as seen by an observer at any point on the earth at any time. Since the surface is spherical, the distortion inherent in flat star maps is avoided. On the other hand, it forces you to view the conste ...
... star chart mounted in such a fashion that it can be oriented to represent the true aspect of the sky as seen by an observer at any point on the earth at any time. Since the surface is spherical, the distortion inherent in flat star maps is avoided. On the other hand, it forces you to view the conste ...
m03a01
... The period of rotation of the Earth itself (the “day”) depends on whether one defines it as relative to the position of the Sun or relative to the fixed stars. The time interval between when any particular (far distant) star is on the celestial meridian, from one day to the next, is the sidereal day ...
... The period of rotation of the Earth itself (the “day”) depends on whether one defines it as relative to the position of the Sun or relative to the fixed stars. The time interval between when any particular (far distant) star is on the celestial meridian, from one day to the next, is the sidereal day ...
The Solar System - RHIG - Wayne State University
... writings. Opponents to the Copernican picture did, however, raise troublesome questions. Why did we not feel the Earth’s motion? It would be centuries before the underlying mechanics became clear and the Coriolis effect would be demonstrated. If the Earth is circling the Sun, why didn’t the stars m ...
... writings. Opponents to the Copernican picture did, however, raise troublesome questions. Why did we not feel the Earth’s motion? It would be centuries before the underlying mechanics became clear and the Coriolis effect would be demonstrated. If the Earth is circling the Sun, why didn’t the stars m ...
What is Astronomy?
... shows that the stars appear to rotate about the "north star" (Polaris). Star rise is about 4 minutes earlier each day. ...
... shows that the stars appear to rotate about the "north star" (Polaris). Star rise is about 4 minutes earlier each day. ...
AST 443/PHY 517 Homework 1
... 11. Show that the angular distance D between two points on the surface of a sphere, with coordinates (α1 ,δ1 ),(α2 ,δ2 ), is given by the expression cosD = sinδ1 sinδ2 + cosδ1 cosδ2 cos(α2 − α1 ) 12. If you were to pilot a plane from New York City to Tokyo on a great circle route, what heading shou ...
... 11. Show that the angular distance D between two points on the surface of a sphere, with coordinates (α1 ,δ1 ),(α2 ,δ2 ), is given by the expression cosD = sinδ1 sinδ2 + cosδ1 cosδ2 cos(α2 − α1 ) 12. If you were to pilot a plane from New York City to Tokyo on a great circle route, what heading shou ...
Celestial Equator
... Earth’s axis were not tilted, then the seasons would be produced only by the varying distance of the Sun. However, in the latter case, the seasons so produced, would occur at the same time for both hemispheres. ...
... Earth’s axis were not tilted, then the seasons would be produced only by the varying distance of the Sun. However, in the latter case, the seasons so produced, would occur at the same time for both hemispheres. ...
Friday, August 28 - Otterbein University
... Why are Polaris and the Sun in opposite directions? • They are not exactly, because “the north direction” and “the south direction” do not exist • Their positions are related because – the direction of Polaris defines the rotation axis of the celestial sphere – The sun is somewhere on the sphere – ...
... Why are Polaris and the Sun in opposite directions? • They are not exactly, because “the north direction” and “the south direction” do not exist • Their positions are related because – the direction of Polaris defines the rotation axis of the celestial sphere – The sun is somewhere on the sphere – ...
astrocoursespring2012lec1-1-5
... the sky day after day due to our orbit and tilt. To understand this better watch this video that explains the sky at different points in its elliptical orbit … and at different times of year in its cyclical , tilting traversal around the sky…. see A Year on Earth… ...
... the sky day after day due to our orbit and tilt. To understand this better watch this video that explains the sky at different points in its elliptical orbit … and at different times of year in its cyclical , tilting traversal around the sky…. see A Year on Earth… ...
Time and Diurnal Motion
... • Eudoxus (360 BC) makes early map of constellations • Hipparchus (130 BC) made a star catalog of 850 stars with some sort of coordinates • Claudius Ptolemy (150 A.D.?): The first really accurate map, 48 constellations, 1025 stars with measured ecliptic longitude & latitude ...
... • Eudoxus (360 BC) makes early map of constellations • Hipparchus (130 BC) made a star catalog of 850 stars with some sort of coordinates • Claudius Ptolemy (150 A.D.?): The first really accurate map, 48 constellations, 1025 stars with measured ecliptic longitude & latitude ...
Ch. 2
... • We cannot see stars near the south celestial pole. • All other stars (and Sun, Moon, planets) rise in east and set in west. ...
... • We cannot see stars near the south celestial pole. • All other stars (and Sun, Moon, planets) rise in east and set in west. ...
Chapter 7 Mapping the Sky
... the other stars (sidereal time) is 3 minutes 56.55 seconds shorter than the mean solar day. The following figure explains this apparent discrepancy. Suppose the day starts when Earth’s orbital position is at A and the Sun on the meridian (that is, directly above the local southern horizon) of an obs ...
... the other stars (sidereal time) is 3 minutes 56.55 seconds shorter than the mean solar day. The following figure explains this apparent discrepancy. Suppose the day starts when Earth’s orbital position is at A and the Sun on the meridian (that is, directly above the local southern horizon) of an obs ...
Chapter 1 Periods of Western Astronomy Prehistoric Astronomy
... Ptolemy of Alexandria • Ptolemy’s model was able to predict planetary motion with fair precision • Discrepancies remained and this led to the development of very complex Ptolemaic models up until about the 1500s • Ultimately, all the geocentric models collapsed under the weight of “Occam’s razor” an ...
... Ptolemy of Alexandria • Ptolemy’s model was able to predict planetary motion with fair precision • Discrepancies remained and this led to the development of very complex Ptolemaic models up until about the 1500s • Ultimately, all the geocentric models collapsed under the weight of “Occam’s razor” an ...
Armillary sphere
An armillary sphere (variations are known as spherical astrolabe, armilla, or armil) is a model of objects in the sky (in the celestial sphere), consisting of a spherical framework of rings, centred on Earth or the Sun, that represent lines of celestial longitude and latitude and other astronomically important features such as the ecliptic. As such, it differs from a celestial globe, which is a smooth sphere whose principal purpose is to map the constellations.With the Earth as center, an armillary sphere is known as Ptolemaic. With the sun as center, it is known as Copernican.