Address Notes ASTR 1000 Fall 2009 Slide Set #1 Divine Movements Dr. H.A. McAlister Dept. of Material science and Stargaz.


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Lunar Feature Found the moon to have cavities, mountains and confounded territory. ... Periods of Venus He found that Venus showed a complete cycle of stages, ...
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Address Notes ASTR 1000 Fall 2009 Slide Set #1 Celestial Motions Dr. H.A. McAlister Dept. of Physics & Astronomy Georgia State University

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The Constellations 88 star groupings in the sky. Those in the northern heavenly side of the equator named by the Greeks. Groups of stars in the great southern sky were named in present day times. Subsets of heavenly bodies are called asterisms . For instance, the "Enormous Dipper" is an asterism of the heavenly body Ursa Major (the huge bear). While groups of stars were named by the Greeks, Arabic names have been for the most part received for individual stars. Stars inside a group of stars are allocated Greek letters as per their brightest. For instance, the brightest star in Orion has the Arabic name Betelgeuse , however it is otherwise called an Orionis. Orion\'s second brightest star, Rigel, is likewise called b Orionis. The twelve heavenly bodies lying along the projection of the Earth\'s circle onto the sky (the ecliptic ) contain the zodiac .

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Winter Sky – Facing North

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Winter Sky – Facing South

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Orion as Depicted by J. Hevelius (1690) (Note this is as seen from outside divine circle)

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Spring Sky – Facing North

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Spring Sky – Facing South

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Celestial Motions The turn of the Earth about its twist hub once like clockwork causes diurnal impacts including day and night and the rising and setting of heavenly protests. The insurgency of the Earth about the sun once at regular intervals… produces yearly impacts, for example, the sun seeming to move concerning the stars along a way in the sky called the ecliptic . The twelve groups of stars lying along the ecliptic involve the zodiac . The obvious movements of heavenly questions on the sky are the consolidated consequence of diurnal and yearly movements and, on account of the planets their own particular orbital movements around the sun.

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The Celestial Sphere north heavenly post Earth\'s twist hub north shaft equator divine equator south post heavenly circle south heavenly post

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Terrestrial Coordinates N * Greenwich * Atlanta scope Equator longitude S For Atlanta: scope = 33 o 45 " N longitude = 84 o 23 " W

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Lunar Months All movements are counterclockwise Time from t 1 to t 2 is the " sidereal month " (This is time required for realignment as for the stars and equivalents 27.3 days.) t 1 Time from t 1 to t 3 is the " synodic month " (This is the time between redundancy of stages and equivalents around 29.5 days. This is the thing that we use for our date-book.) t 2 t 3

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Lunar Phases first quarter waxing gibbous waxing bow daylight dusk full moon new moon twelve midnight to the Sun dawn Earth winding down gibbous fading sickle daylight second from last quarter

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Questions About Lunar Phases What is the time interim amongst new and full moons? What time does the full moon come full circle? What time does the new moon come full circle? What time does the new moon rise? What is the period of the moon that finishes at dusk? What is the period of the rising moon at dusk? What is the period of the setting moon at midnight? two weeks midnight twelve dawn first quarter full first quarter

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"Earthshine" waxing bow Moon Sunlight reflected off day lit side of Earth lights up dull some portion of sickle moon. daylight to the Sun Earth The impact is most evident just before and soon after new moon daylight

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The Tides 4. On the far side, the Earth is successfully pulled Moonward far from the water, yielding another high tide. 3. The water on the close side of the Moon is pulled far from Earth, raising a high tide. Earth Moon 2. The nearness of the Moon creates a gravitational fascination on the Earth whose quality fluctuates conversely with separation from the Moon. 1. Envision a consummately round Earth consistently overflowed by a sea.

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Moon Factoids A " blue moon " is when more than one full moon happens in the same date-book month. The moon experiences " synchronous " turn and upheaval (i.e. the times of pivot and insurgency are indistinguishable), so one side of the moon dependably confronts the Earth. The " harvest moon " includes the ascending of the full moon in late September and early October. Because of the precise tilt of the moon\'s orbital plane with that of the Earth, the brilliant moon seems to ascend at about the same time in the early night when the moon is full at the season of the " harvest time equinox ".

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Moon Myths The period of the moon has no impact on human conduct. There is no such thing as the "dim side of the moon." We did undoubtedly arrive people on the moon in the six Apollo arrivals between July 1969 and December 1972. For additional about "insane people", the "moon deception" and other galactic pseudoscience, see: www.astrosociety.org/training/assets/pseudobib.html

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Tilt of Earth\'s Spin Axis 23.5 o tilt The Earth\'s twist hub is tilted by 23.5 degrees off vertical regarding the "ecliptic plane" (plane of the Earth\'s circle around the sun) The twist hub remains basically parallel to itself over the span of the year

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Summer Solstice – 21 June tropic of Cancer cold circle daylight equator antarctic circle daylight

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Winter Solstice – 21 December tropic of Cancer ice circle daylight equator antarctic circle daylight tropic of Capricorn

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Vernal Equinox – 21 March ice circle daylight tropic of Cancer equator tropic of Capricorn daylight antarctic circle

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Autumnal Equinox – 21 September ice circle daylight tropic of Cancer equator tropic of Capricorn daylight antarctic circle

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The Culminating Sun The sun comes full circle in the pinnacle (i.e. straight overhead) at twelve for eyewitnesses situated on the tropic of Cancer (scope = 23.5 o N) upon the arrival of the late spring solstice . The sun comes full circle in the pinnacle at twelve for onlookers situated on the tropic of Capricorn (scope = 23.5 o S) upon the arrival of the winter solstice . The sun comes full circle in the peak (i.e. straight overhead) at twelve for spectators situated on the equator (scope = 0 o ) on the times of the equinoxes .

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Other Seasonal Extremes The sun never ascends for eyewitnesses north of the ice circle upon the arrival of the winter solstice The sun never sets for spectators north of the cold circle upon the arrival of the mid year solstice The above conditions are turned around for the antarctic circle . The sun moves 360 o around the skyline for onlookers situated at the north and south posts on the times of the equinoxes .

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Tilt of Earth\'s Spin Axis W N S E winter solstice summer solstice equinox The sun ascends on the east point and sets on the west point on the times of the equinoxes, giving equivalent times of "day" and "night". The sun is in the sky for the longest term on the late spring solstice and lights up the northern side of the equator generally specifically.

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Temperature Effect Summer days are longer and the sun is more serious (because of the more straightforward brightening point). In this way summer is more smoking than winter. There is a slack of the seasons when contrasting the dates of the solstices and the real extremes in temperature since it requires investment to warm up the seas and air at the onset of summer and to chill them at the onset of winter. On the off chance that the Earth\'s twist pivot were not tilted by some edge, we would have no seasons.

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Precession of Earth\'s Spin Axis 5. Turn pivot now indicates Polaris. a long time from now, Vega will be our "shaft star" 4. Earth reacts to this draw by gradually "precessing" its twist hub around a circle in the sky once at regular intervals 23.5 o 2. Moon\'s orbital plane is tilted by 5 o from our equator 3. Moon\'s gravitational draw on Earth endeavors to maneuver swell into lunar orbital plane 1. The revolution of the Earth misshapes it into an "oblate" spheroid smoothed at the posts

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Shadows and Eclipses Sun Penumbra Umbra Earth

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Eclipse of the Moon (Lunar Eclipse) Earth\'s Orbit Moon\'s Orbit Occurs at Full Phase when Moon is additionally at the "line of hubs" of its circle as for the ecliptic A lunar overshadowing goes on for a long time and can be seen from most of the Earth\'s surface

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Eclipse of the Sun (Solar Eclipse) Earth\'s Orbit Moon\'s Orbit Occurs at New Phase when Moon is likewise at the "line of hubs" of its circle as for the ecliptic A sun powered obscuration goes on for just for a couple of minutes and must be seen from extremely limited areas on the Earth\'s surface

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Total and Annular Eclipses Vertex of Umbral shadow is at or underneath Earth\'s surface, so an aggregate shroud is conceivable Vertex of Umbral shadow is over Earth\'s surface, so just an annular obscuration is conceivable

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Example of a Solar Eclipse Path See Richard Monk\'s site page on shrouds: www.williams.edu/stargazing/IAU_eclipses/

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Total Solar Eclipse of 21 June 2001 from Zimbabwe See Richard Monk\'s site page on shrouds: www.williams.edu/cosmology/IAU_eclipses/Bailey\'s Beads Solar Corona "Precious stone Ring"

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Upcoming Lunar and Solar Eclipses Solar Eclipses: 15 Jan 2009 (annular) – Asia & Africa 11 July 2010 (aggregate) – South Pacific Ocean 4 Jan 2011 (fractional) – Europe, Africa & focal Asia 1 Jun 2011 (incomplete) – east Asia, far N. America, Iceland 1 Jul 2011 (incomplete) – south Indian Ocean 25 Nov 2011 (annular) – south Africa, Antactica, Tasmania, New Zealand The following aggregate sun oriented shrouds obvious from the U.S. will be on 21 Aug 2017 and 8 Apr 2024. The 2017 obscuration will be unmistakable from Georgia. Lunar Eclipses: 31 Dec 2009 – not U.S. 15

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