ASTR 1345 1st Edition Lecture 5 Outline of Last Lecture I. Powers of Ten A. Positive B. NegativeII. Astronomical Units and ParsecIII. The Night SkyA. Definition of an AsteroidB. Definition of a Black holeC. Definition of a CometD. Definition of a MeteoroidE. Groups of GalaxiesF. Definition of AsterismsG. Definition of a Celestial SphereH. Definition of a ConstellationOutline of Current Lecture I. The Geocentric UniverseII. The SunA.Definition of Celestial EquatorB.North and South Celestial PoleC.Definition of DeclinationD.Definition of Right AscensionE.Prime MeridianF.Diurnal MotionG.Sidereal PeriodH.ZenithI.CircumpolarJ.EclipticK.EquinoxL.Winter and Summer SolsticeM.ZodiacCurrent Lecturel.These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Behind the Moon are fixed stars that appear to move together around Earth in a regular motion.Among the stars were found planets, following irregular paths but never straying from the Sun’s path, which is known as ecliptic. Many stars we think are single are actually binary—double stars which are very close together. 23 degrees is the angle of Earth’s tilt and it tilts about 1 degree each day.ll.Temperature and seasons are determined by the duration of daylight at any place and the height of the Sun in the sky there. A solar day is from noontime to next noontime, for Earth it’s 24 hours.A. The celestial equator is a great circle on the celestial sphere 90 degrees from the celestial poles.B. The north celestial is located on the celestial sphere directly above Earth’s northern rotation pole. The south celestial pole is located on the celestial sphere directly above Earth’s southern rotation pole.C. Declination is the coordinate on the celestial sphere exactly analogous to latitude on Earth, measured North and South of the celestial equator.D. Right Ascension is the celestial coordinate analogous to longitude on Earth and measured around celestial equator from the vernal equinox.E. The prime meridian is zero of longitude on Earth.F. Diurnal Motion is a cyclic motion with a one day period.G. A sidereal period is an orbital period of 1 object about another measured with respect to the stars. H. Zenith is the point directly overhead anywhere on Earth. Polaris is the only star that doesn’t appear to move left to right because it always remains at the North Pole’s Zenith.I. Circumpolar are stars and constellations that never go below the horizon. As you go further south in the northern hemisphere the number of stars and constellations that are circumpolar decrease and vice versa.J. Ecliptic is the annual path of the Sun on the celestial sphere, the plane of Earth’s orbit around the Sun.K. An equinox is either of the two days of the year when the Sun crosses the celestial equator and is directly over Earth’s equator. A vernal equinox is the point on ecliptic where the Sun crosses the celestial equator from south to north, this is in the beginning of spring around March 21. The autumnal equinox is an intersection of ecliptic and celestial equator where the Sun crosses the equator moving from north to south and this is in the beginning of autumn around September 23.L. The winter solstice is the point on ecliptic farthest south of celestial equator. It’s the day when the Sun rises to the lowest height at noon and signals the day of the yearin the northern hemisphere with fewest number of daylight hours. The summer solstice is the point on the ecliptic where the Sun is farthest north of the celestial equator. This is the day with the largest number of daylight hours in the northern hemisphere. (Around June 21).M. A zodiac is a band of 13 constellations around the sky through which the Sun appearsto move throughout the