• Study Resource
  • Explore Categories
    • Arts & Humanities
    • Business
    • Engineering & Technology
    • Foreign Language
    • History
    • Math
    • Science
    • Social Science

    Top subcategories

    • Advanced Math
    • Algebra
    • Basic Math
    • Calculus
    • Geometry
    • Linear Algebra
    • Pre-Algebra
    • Pre-Calculus
    • Statistics And Probability
    • Trigonometry
    • other →

    Top subcategories

    • Astronomy
    • Astrophysics
    • Biology
    • Chemistry
    • Earth Science
    • Environmental Science
    • Health Science
    • Physics
    • other →

    Top subcategories

    • Anthropology
    • Law
    • Political Science
    • Psychology
    • Sociology
    • other →

    Top subcategories

    • Accounting
    • Economics
    • Finance
    • Management
    • other →

    Top subcategories

    • Aerospace Engineering
    • Bioengineering
    • Chemical Engineering
    • Civil Engineering
    • Computer Science
    • Electrical Engineering
    • Industrial Engineering
    • Mechanical Engineering
    • Web Design
    • other →

    Top subcategories

    • Architecture
    • Communications
    • English
    • Gender Studies
    • Music
    • Performing Arts
    • Philosophy
    • Religious Studies
    • Writing
    • other →

    Top subcategories

    • Ancient History
    • European History
    • US History
    • World History
    • other →

    Top subcategories

    • Croatian
    • Czech
    • Finnish
    • Greek
    • Hindi
    • Japanese
    • Korean
    • Persian
    • Swedish
    • Turkish
    • other →
 
Profile Documents Logout
Upload
EQUINOCTIAL vLOBE  ·
EQUINOCTIAL vLOBE ·

... Fig. 1. Let P be the pole of the ecliptic CV" $ � vY. N the pole of the equator CV" �, cutting the ecliptic in
a PDF version of the Uniglobe Manual.
a PDF version of the Uniglobe Manual.

... Bearing. The horizontal angle between a reference direction and another direction of interest. It is usually measured from 0° at true north clockwise through 360°. ...
The motions of the Earth
The motions of the Earth

... Avoid ambiguities in date formats (DD/MM/AAAA vs MM/DD/AAAA) Ease calculations of time intervals Bypass the “October 1582” problem (Julian vs Gregorian calendars). Uses a single positive number to state both date and time with arbitrary accuracy Julian date = “number of days elapsed since January 1s ...
THE EVIDENCE FROM KNOSSOS ON THE MINOAN CALENDAR
THE EVIDENCE FROM KNOSSOS ON THE MINOAN CALENDAR

... celestial  events,  such  as  sunrise  and  sunset  at  the equinoxes and solstices, from the beginning  of the Middle Bronze Age (ca 2000 BCE). Thus it  is  likely  that  they  had  considerable  knowledge  of the motions of the celestial bodies much ear‐ lier.  The debated dates of the Greek const ...
SU3150-Astronomy - Michigan Technological University
SU3150-Astronomy - Michigan Technological University

... the same rate daily keeping their angular separation constant For this reason the Right Ascension and Declination are used as universal coordinates to document star positions in star catalogs that could be used by anyone anywhere in the world Position of the Vernal equinox too changes slightly due t ...
The celestial sphere
The celestial sphere

... ASTR211: COORDINATES AND TIME 2. Diurnal motion of celestial bodies Stars, planets, Sun and Moon all exhibit diurnal motion across celestial sphere. ...
3 - Celestial Sphere
3 - Celestial Sphere

... The celestial sphere is a model you can use to describe, explain, and predict the motion of the Sun and the stars in the sky. It models how the sky looks from Earth. Identify the underlined concepts on your celestial sphere: 1) There are imaginary points such as the North and South Celestial Poles ( ...
Mathematical Methods in Ancient Astronomy
Mathematical Methods in Ancient Astronomy

... character; find simple periodic functions, whose combination describes, within given limits of accuracy, the observed phenomena. While in our harmonic analysis the basic periodic functions admit, at least in principle, a direct geometric interpretation by simple harmonic oscillations, no such interp ...
COORDINATES, TIME, AND THE SKY John Thorstensen
COORDINATES, TIME, AND THE SKY John Thorstensen

... equal to your latitude. Note that altitude is measured along a great-circle arc which passes through the object and the zenith. The existence of a pole implies the existence of a celestial equator, which is the set of all directions 90 degrees from (either) pole. If you stand on the north or south p ...
13. Right Ascension and Declination
13. Right Ascension and Declination

... • RA-dec co-ordinates are harder to interpret in terms of position in the sky and object visibility than HA-dec coordinates. • RA-dec co-ordinates are still not fixed for objects which exhibit annual motion, i.e. the Sun, planets and other solar system objects. ...
night sky a field guide to the heavens
night sky a field guide to the heavens

... beyond all expectation, what could have been named that would be more marvelous than these things, or that nations beforehand would less venture to believe could be? Nothing, me thinks: so wonderous strange had been this sight. Yet how little, you know, wearied as all are to satiety with seeing, any ...
Package `moonsun`
Package `moonsun`

... name of a planet (appended to dates in result) TRUE if it is inner, FALSE if outer planet period of a planet (tropical years) longitude at epoch 1990 January 0.00 (degrees) longitude of the perihelion (degrees) eccentricity of the orbit semi-major axis of the orbit (AU) inclination of the orbit (deg ...
Histograms Constructed from the Data of 239Pu Alpha
Histograms Constructed from the Data of 239Pu Alpha

... Earlier, the shape of histograms of the results of measurements obtained in processes of different physical nature had been shown to be determined by cosmophysical factors [1]. Appearance of histograms of a similar shape is repeated periodically: these are the neara-day, near-27-days and annual peri ...
Computation of a comet`s orbit - Iowa Research Online
Computation of a comet`s orbit - Iowa Research Online

... time will show how close these approximations are. The reasons for this state of affairs are var­ ious and to give even a passable explanation of them, ana of the theories by which the many changes of position are taken into account, would require more than the entire length of this paper. I must co ...
Week 1
Week 1

... From our perspective on Earth the stars appear embedded on a distant 2-dimensional surface – the Celestial Sphere. ...
presentation - CESAR Project website
presentation - CESAR Project website

... The main objective is to train students in both general science and engineering basics providing them with firsthand experience in astronomy in an IBSE learning environment Observations allow students to learn, with first-order scientific tools, the basics of an astronomical research, aiming to arou ...
The Celestial Sphere - George Mason University
The Celestial Sphere - George Mason University

... • The full 360 degrees circle is broken up into 24 hours, so one hour of RA = 15 degrees. • The lines of RA all converge at the celestial poles, so two stars one hour of RA apart will not necessarily be 15 degrees in angular separation on the sky (only if they are on the celestial equator will they ...
THE CONSTELLATIONS OF THE ZODIAC G. Iafrate, M. Ramella
THE CONSTELLATIONS OF THE ZODIAC G. Iafrate, M. Ramella

... Chaldean people (Babylonians) around 500 BC. This division of the ecliptic into twelve equal zones of celestial longitude ends up being the first known celestial coordinates system. The Babylonian calendar assigned each month to a sign, beginning with the position of the Sun at vernal equinox (March ...
THE CONSTELLATIONS OF THE ZODIAC
THE CONSTELLATIONS OF THE ZODIAC

... Chaldean people (Babylonians) around 500 BC. This division of the ecliptic into twelve equal zones of celestial longitude ends up being the first known celestial coordinates system. The Babylonian calendar assigned each month to a sign, beginning with the position of the Sun at vernal equinox (March ...
FullText - Mediterranean Archaeology and Archaeometry
FullText - Mediterranean Archaeology and Archaeometry

... point between the two extremes and divide the solar cycle into a warm and a hot season. The vernal and autumnal equinoxes divide the year into two halves, as do the summer and winter solstices (Hughes, 2005). Our findings on the third platform located on the northern terrace provide strong evidence ...
Celestial Globes Armillary Spheres
Celestial Globes Armillary Spheres

... points furthest away from the ecliptic, above and below. the highest point of a body, i.e., the sun during the summer solstice. a time when the day and night hours are equal, or where the ecliptic path crosses the celestial equator. This occurs twice in a year, spring (vernal), and in winter. ...
3.2a Right Ascension and Declination
3.2a Right Ascension and Declination

... If a person was able to see the night sky shown above for a full day, the full band of stars would pass in front of them, moving steadily towards the right. The longitude reference point was more difficult. Many countries have laid claim to the Prime Meridian – the Chinese once used a gate from the ...
CHAPTER 3, Diurnal Motion - The College of New Jersey
CHAPTER 3, Diurnal Motion - The College of New Jersey

... sense) from the horizon. When an object is below the horizon, it's angular distance from the horizon, or altitude, is assigned a negative value. Objects make one upper transit and one lower transit each day. For an observer in the Northern Hemisphere, both upper and lower transit will occur above th ...
Lecture 1 - Simon P Driver
Lecture 1 - Simon P Driver

... •  At  what  local  /me  would  the  object  rise  and  set  on  1st  Feb:   –  RA  overhead  on  7th  Feb  is  ~9h  (see  answer  to  part1)   –  RA  overhead  on  1st  Feb  is  ~8.5h  (2hr  per  month  so  ~0.5hr  per  week) ...
Harappan Astronomy
Harappan Astronomy

... astronomy was based on the Sun, the Moon or the stars. There is extensive archaeological evidence that the Harappans traded with cultures in West Asia ((Kenoyer, 1998), Possehl, 2002)). The constellations as we know them today were formalised in Mesopotamia around 3000 BC ((see for example Wikipedia ...
< 1 2 3 4 5 6 8 >

Epoch (astronomy)

In astronomy, an epoch is a moment in time used as a reference point for some time-varying astronomical quantity, such as the celestial coordinates or elliptical orbital elements of a celestial body, because these are subject to perturbations and vary with time. These time-varying astronomical quantities might include, for example, the mean longitude or mean anomaly of a body, the node of its orbit relative to a reference plane, the direction of the apogee or aphelion of its orbit, or the size of the major axis of its orbit.The main use of astronomical quantities specified in this way is to calculate other relevant parameters of motion, in order to predict future positions and velocities. The applied tools of the disciplines of celestial mechanics or its subfield orbital mechanics (for predicting orbital paths and positions for bodies in motion under the gravitational effects of other bodies) can be used to generate an ephemeris, a table of values giving the positions and velocities of astronomical objects in the sky at a given time or times.Astronomical quantities can be specified in any of several ways, for example, as a polynomial function of the time-interval, with an epoch as a temporal point of origin (this is a common current way of using an epoch). Alternatively, the time-varying astronomical quantity can be expressed as a constant, equal to the measure that it had at the epoch, leaving its variation over time to be specified in some other way—for example, by a table, as was common during the 17th and 18th centuries.The word epoch was often used in a different way in older astronomical literature, e.g. during the 18th century, in connection with astronomical tables. At that time, it was customary to denote as ""epochs"", not the standard date and time of origin for time-varying astronomical quantities, but rather the values at that date and time of those time-varying quantities themselves. In accordance with that alternative historical usage, an expression such as 'correcting the epochs' would refer to the adjustment, usually by a small amount, of the values of the tabulated astronomical quantities applicable to a fixed standard date and time of reference (and not, as might be expected from current usage, to a change from one date and time of reference to a different date and time).
  • studyres.com © 2025
  • DMCA
  • Privacy
  • Terms
  • Report