Presentation on theme: "Celestial Coordinate Systems K-12 Coordinate Curriculum"— Presentation transcript:
1 Celestial Coordinate Systems K-12 Coordinate Curriculum Karen LancourChandra Resource AgentandMark Van HeckeK-12 Celestial and Terrestrial Coordinate curriculumDeveloped by Karen Lancour and Mark VanHecke - Chandra Resource AgentsCurriculum is designed to align with National StandardsInterdisciplinary – Science, Geography, Math, Language Arts, Problem Solving
2 Night Sky Sky appears as inside of a very large sphere 88 constellationsImportant to specify positions of objects in the sky in relation to one anotherCoordinate systemsSky appears as inside of a very large sphere.Human eye can see 6000 stars unaided.Sky is divided into 88 regions called constellations.Stars appear to rotate around the earth but earth is actually rotating once a day – diurnal motion.It is important to specify positions of objects in the sky in relation to one another.
3 Appearance of the Night Sky 3-dimensional space appears as a 2-dimensional flat surfaceLike a photograph or drawingDifferent methods are used to determine distance from earth
4 Spherical Coordinates Geographic & Celestial systems are spherical coordinate systems2-dimensional systemsFundamental Plane –EquatorPolar AxisNorth & South PolesCoordinate systems for the earth and sky are spherical coordinate systems.2 dimensional systems – two angular measurements specify an object’s position relative to another.Distance is very great and is measured by other means.A sphere has 360 degrees.Sphere is divided in half by a fundamental plane or reference plane. (Equatorial Plane)The great circle around the fundamental plane is equidistant from the poles. (Equator)Rotation or polar axis is a line that passes through the poles perpendicular to the center of the plane.
5 Celestial Sphere Huge, hollow, imaginary sphere Infinite radius Appears to rotate east to westEarth is actually rotating west to eastCelestial EquatorNorth Celestial Pole and South Celestial PoleImage sky as a great, hollow, sphere with infinite radius surrounding the earth.It appears to rotate around the earth every 24 hours from east to west.Earth is actually rotating on its axis from west to east.Equator is extended out from earth to the form celestial equator.Poles are extended out to form north celestial pole and south celestial pole.
6 Coordinate Systems – Different Reference Planes Major Coordinates SystemsDifferent reference planes for Celestial SphereNorth-South Axis perpendicular to reference planeDeveloped to facilitate different perspectivesThere are several coordinates systems.Each coordinate system has a different reference plane.The rotational axis and poles for each reference plane are perpendicular to that plane.Each system selects the reference plane to facility study of particular types of objects.Coordinates for the celestial coordinate system are modeled after the geographic coordinate systems on earth.
7 Coordinates – Angular Measurements Latitude-like coordinatesLongitude-like coordinatesZero point of longitudeLocal meridianCoordinates are specified byAngular measurement from the reference plane along another great circle perpendicular to the plane. These are latitude-like coordinatesAngular measurement around the great circle from the zero reference point to the local meridian. These are longitude like coordinates.The local meridian is the circle going from the north pole through the object to the south pole.
8 Latitude and Longitude Circles of latitudeSame latitudeMeridians of longitudeSame longitudeZero point or prime meridianLatitude-like coordinates:Circles of Latitude - Circles parallel to the Equatorial plane from equator to each pole.Angle with vertex at center of the sphere between a given circle of latitude and the equator.Latitude is the same for all points along a circle of latitude.Longitude-like coordinates:Semicircles passing through the poles (meridians of longitude)A specified meridian to serve as the zero point or meridian along the equator.Angle with vertex at center of sphere between a given meridian of longitude and the zero meridian.All points along a meridian have same longitude.0 to 360 degrees may be divided into 0 to degrees East and 0 to degrees West.
9 Geographic System Equator is 0 degrees North Pole is 90 degrees N. South Pole is 90 degrees S.Greenwich meridian0 to 180 degrees east0 to 180 degrees westLatitude:Equator is 0 degrees latitude.North of equator extends from 0 to + 90 degrees or 90 degrees North at the pole.South of equator are 0 to - 90 degrees or 90 degrees South at the pole.Longitude:0 degree longitude is the Greenwich meridian.0 to 360 degrees may be divided into 0 to degrees East and 0 to degrees West.
10 Geographic Coordinates 360 degrees of arc in a circleEach degree has 60 minutes of arcEach minute of arc has 60 seconds of arcCoordinatesThere are 360 arc (o) degrees in a circleEach arc degree has 60 arc (‘) minutesEach arc minutes has 60 arc (“) seconds
11 Geographic and Celestial Coordinate Systems SphericalCoordinateSystemGeographicLatitude -LongitudeHorizonAlt-AZLocal EquatorialHA – DecEquatorialRA-DecEclipticLongitude-LatitudeGalacticEarth vs. SkyBased SystemEarthEarth - LocalEarth – LocalSkyGreat Circle ofFundamentalPlane( x-y plane)EquatorAstronomicalCelestial EquatorGalactic PlanePolar Axis(z axis)North and SouthEarth PolesZenith, NadirCelestial PolesNorth and SouthNorth and South Ecliptic PolesNorth and South Galactic PolesLatitude-LikeCoordinatesN is + 90S is – 90 Latitude (L, lat)0 to 90N0 to 90SAltitude (Alt)Latitude of Observer0 to + 90Declination (Dec)0 to +90 (N)0 to – 90 (S)0 to + 90 (N)0 to – 90 (S)Ecliptic Latitude (Lat)0 to – 90 (S)Galactic Latitude (B)Longitude-Like360Longitude (long)0 to 180 E and0 to 180 WAzimuth (AZ)N=0, E=90S=180, W=270Clockwise - LH(E to W)Hour Angle(HA)0 – 24 Hrs.Right Ascension (RA)0 to 24 hr or0 to 360Counterclockwise-RH (W to E)Ecliptic Longitude(Lon)Counterclockwise- RH(W to E)Galactic Longitude(L)Counterclockwise-RH(Zero Point)Prime MeridianNorth Point ofCelestialMeridianZero-PointAffixed to EarthVernal EquinoxZero-Point Affixed to SkyGalactic CenterPhysical BasisCircumferenceof the EarthDirection ofGravityEarth’s RotationEarth’s OrbitalMotionUsed For:DeterminingLocationPersonalObservation andSome telescopesSetting ofTelescopesTo Track ObjectsCatalogingPositions and toDetermineLocationsSolar SystemStructureMilky Way and OtherGalactic Structures
12 Horizon System For Personal Observation Plane of local horizon Zenith – 90 degrees above horizonNadir – 90 degrees below horizonHorizon affected by the latitude of the observer.Horizon system is used for personal observation of objects in the sky.2. Plane of Local Horizon is the fundamental plane.3. Zenith is the point 90 degrees above the horizon – visible4. Nadir is the point 90 degrees below to horizon – not visible
13 Horizon System - Alt-AZ Altitude – angle of object above the horizonAzimuth – angle of object around the horizon clockwise from north
14 Horizon System - Alt-az Altitude = 0 to 90 degAzimuth = 0 to 360 degNorth point definedNorth = 0 degEast = 90 degSouth = 180 degWest = 270 degAltitude is the angular measure for the location of an object above the horizon.Azimuth is the angular distance between North and the current direction of viewing which is the compass direction toward the horizon point directly below the object.North is defined as the meridian going from the zenith through the North Celestial Pole (Polaris) to the horizon.The angle is measured in a clockwise direction where North is 0 degrees, East is 90 degrees, South is 180 degrees and West is 270 degrees.The four principal directions are called cardinal points.
15 Horizon System Observer’s view Geography dependent Altitude of NCP = latitude of observer.Time and Season dependentSame object has different coordinates at different timesThe north point is the meridian from the zenith through the north celestial pole to the horizon.Extending the meridian in the opposite direction on the horizon defines the south point.The Celestial Sphere intersects the horizon at the east and west points.Stars move parallel to the celestial equator.Stars rise in the east and set in the west.Circumpolar stars (above declination of 60 degrees) never set.The arc of the stars path is affected by the observer’s latitude.The Altitude of the North Celestial Pole is the equal to the observer’s latitude.The Altitude of the Zenith always equals 90 degrees.
16 Local Horizon – North Pole View from North PoleZenith is North Celestial PoleLocal horizon is parallel to Celestial EquatorStars rotate parallel to horizon (celestial equator)Stars never rise and setViewed from the North Pole, the zenith is on the north celestial pole.The local horizon is on the celestial equator.Stars rotate parallel to celestial equator (in this case the horizon).When viewed from the north pole, stars never rise and set.
17 Local Horizon – Fairbanks View from FairbanksAltitude of NCP equals latitude of observer.Stars move parallel to the celestial equatorAs one moves south,the NCP moves away from zenith toward the north point of horizonView from FairbanksAltitude of North Celestial Pole equals latitude of observer.Stars move parallel to the celestial equator.As one moves south, the CNP moves away from zenith toward the north point of horizon.The stars rise in the east and set in the west.Note how the arc of the stars movement deepens as the observer’s latitude goes further south.
18 Local Horizon - Seattle View from SeattleStars rise in east and set in westNCP moves further away from ZenithArc of star movement above horizon gets steeperAs viewed from SeattleStars rise in east and set in westNCP moves further away from ZenithArc of star movement above horizon gets steeper.
19 Local Horizon – Los Angeles View from Los Angeles34 deg latitudeNCP at 34 deg above the horizon and 56 deg from zenithAll observers on 34th parallel see the same star pathStar path is steeperView from Los Angelesdegrees latitudeNCP at degrees above the horizon and degrees from zenithAll observers on parallel see same star pathStar path steeper
20 Local Horizon – Equator View from equatorNCP is parallel to local horizonCelestial Equator is perpendicular to local horizonZenith is on celestial equatorStars rise and set perpendicular to horizonView from equatorThe North Celestial Pole is parallel to local horizonCelestial equator is perpendicular to local horizonThe Zenith is on celestial equatorStars rise and set perpendicular to horizon
21 Local Equatorial System Stars rise in east and set in westMotion of each star = parallel of declination on the Celestial SphereCelestial Equator is half way between NCP and SCPRelated to sidereal “star” timeUsed to track motion of stars
22 Local Equatorial System “HA-dec” Used to track objectsLatitude (Declination) is from the Celestial SphereLongitude uses Hour AngleFollows star path from east to westIs still time dependent at local meridianUsed to track objects along the parallel of declination.Determine the Declination “latitude” on the celestial sphere.Use the local meridian for your horizon and objects Right Ascension todetermine hour angle .4. HA (obj) = LST – RA (obj)
23 Hour AngleTime before and after star reaches zenith of its path
24 Equatorial System “RA-dec” Used to catalog objectsCelestial SphereCelestial EquatorNCP and SCPDeclination (latitude)Right Ascension (longitude)Vernal Equinoxit is an extension of the earth onto the sky called the celestial sphere.The fundamental plane is the celestial equator, which is an extension of the earth’s equator upon the celestial sphere.The axis of rotation is an extension of the North – South Pole axis of the earth.Latitude like coordinates are called declination (dec.).Longitude-like coordinates are called right ascension (R.A.).6. Zero point for RA is Vernal Equinox.
25 Declination Angle above Celestial Equator Parallels of Declination CE = 0 degNCP = 90 degSCP = - 90 degDeclination is the angle of the object above the celestial equator.Parallels of declination similar to parallels of latitude.Celestial equator is 0 degreesNCP is 90 degrees and SCP is – 90 degrees
26 Right Ascension Hour circles or “meridians” Equator = 360 arc deg circumferenceMeasured as hours (24 hours)1 hr = 15 arc degreesCounterclockwise0h = vernal equinoxThe longitudinal lines called hour circles go from the celestial North Pole to the celestial South Pole crossing the equator.R.A. can be expressed in values between 0 deg and 360 deg but is more often given in time units.R.A. is measured counterclockwise or west to east.R.A. can be expressed in values between 0 o and 360 o but is more often given in time units.The 360 deg along the equator is divided into time units of 24 hours (h). One hour equals 15 min of arc
27 Ecliptic From Earth, Sun ‘s apparent path Inclined 23.5 deg to Celestial EquatorVernal EquinoxAutumnal equinoxWinter SolsticeSummer Solstice
28 Ecliptic System Earth revolves around sun = ecliptic Ecliptic is fundamental planeAxis of rotationNorth Ecliptic PoleSouth Ecliptic PolePlanets have similar paths around sun
29 Ecliptic System & Planets Used to study solar systemExcept for Pluto at 17 degreesOrbital Inclination within 7 degrees of EclipticPlanetOrbital InclinationMercury7.00°Venus3.39°Earth0.00°Mars1.85°Jupiter1.31°Saturn2.49°Uranus0.77°Neptune1.77°Pluto17.15°Planet Orbital Inclination Mercury 7.00° Venus 3.39° Earth 0.00° Mars 1.85° Jupiter 1.31° Saturn 2.49° Uranus 0.77° Neptune 1.77° Pluto 17.15°
30 Zodiac Constellations As earth revolves,sky appearance changes.Constellations around ecliptic called Zodiac
31 Galactic System Study Milky Way and beyond Plane of Galaxy Inclined about 63 deg to Celestial EquatorUsed to study objects beyond our Solar System within our Milky Way Galaxy and outside our galaxy in relationship to the plane of the Milky Way.The Galactic Plane, or Galactic Equator, is used as reference plane. This great circle of the celestial sphere best approximates the visible Milky Way.a spiral galaxy, which is very flat with a core that bulges From Earth, the center of the galaxy is in the constellation Sagittarius.The mean plane of the galaxy is inclined at about 63° (62.9°) to the celestial equator.
32 Galactic System Fundamental plane = plane of Milky Way Galactic EquatorNorth Galactic PoleSouth Galactic PoleCenter of Galaxy
33 Galactic Coordinates Galactic Latitude NGP = 90 deg SGP = -90 deg Galactic LongitudeCounterclockwise0 to 360 deg0 = center of our galaxyGalactic latitude is measured from the galactic equator at 0 degrees to 90 degrees at the Galactic North Pole and -90 degrees at the Galactic South Pole. north (positive numbers) or south (negative numbers)Galactic longitude is measured eastward along the galactic plane from the galactic center. Galactic longitude (l) is measured in from 0 to 360 deg. east ward along the galactic equatorThe Longitude Zero Point lies in the direction of the galactic center
34 Coordinate Curriculum K-13 Elementary ActivitiesMiddle School – Junior High ActivitiesSenior High ActivitiesAligned to National StandardsInvolve science, geography, math, language arts, art, problem-solvingIntroductory, skill-development, and assessment activities
35 ChandraRelated to1. Chandra Classroom-ready activities as Stellar Evolution, Variable Stars, Electromagnetic Spectrum, Imaging for Junior and Senior High2. ds9 and Visual Observatory3. Chandra Sky Map
36 Science Olympiad Related to 1.Elementary Science Olympiad events in Starry, Starry Night and Map Reading2.Reach for the Stars and Road Scholar for Division B3.Astronomy and Remote Sensing for Division C4.Trial events as Global Positioning Systems
37 Tools of Astronomy3-d models, globes, grids, star maps, charts, graphs, quadrant, astrolabe, cross-staff, pinhole protractor, parallax, hand anglesbinoculars, telescope, star lab, planetariumComputer technology as Chandra Sky Map, ds9, Remote Sensing, GPS, Sky Map programsCoordinates, measurements, angles, relative positions, times, navigation
38 Sample ActivityChandra’s Stellar Evolution poster recently in the Science Teacher magazineMap projectionsCoordinate gridsProblem-solving
39 Chandra’s Stellar Evolution Poster Available from Chandra websiteInteractive version on Chandra websiteBackground information and classroom ready materials available.
40 Map Projections Attempts to represent sphere on flat map Always some distortionTypes to emphasize specific regions of sphere
41 Sky Maps Sky maps have East and West reversed Designed so that when placed above your head, directions willcorrespond.3. Maps are usually by month and for regions of earth.
42 Whole Sky (Aitoff) Projection Whole sky projection is popular with astronomersProjections for Equatorial, Ecliptic, or Galactic Systems
47 Chandra Sky Map of images produced by Chandra Chandra Sky Map of images produced by ChandraUses the Galactic Coordinate SystemClink on colored symbol to access image and information on the ImagesWill give the Equatorial Coordinates To explore the X-Ray Sky, click on a colored diamond in the sky map. Find out more about Galactic Navigation by taking a tour of the Galactic Coordinate System! Return to Photo Album Revised: January 03, 2005
48 Mercator - Equatorial Region Shows the regions near the equatorLess distortion when put on a flat surfaceRegions north and south of equator
49 SC001 Equatorial RegionUsing Equatorial (RA-dec) System
50 SCOO1 - DeclinationDeclination (latitude-like) from +60 deg above to -60 deg below celestial equator.Degrees, minutes, and seconds of arc
51 SC001 – Right AscensionRight Ascension (longitude-like) from 0-24 hrs.Hours, minutes, secondsHour circles “meridians” of Right Ascension
52 Polar RegionCircumpolar regionNorth versionSouth version
53 SC002 - Declination North Version 30 – 90 deg declination Parallels of declinationEquatorial region not visible
54 SC002 – Right Ascension North polar version RA = 0 to 24 hours Hour circles or “meridians”Note the chart symbols for objects and magnitude