Fayetteville-Manlius C.S.D.

 

Observational Astronomy

 

High School Course Curriculum

 

 

 

Thank You

The following syllabus was written by Michael Osborn, edited by Ronald Hauk and funded by a curriculum development grant from the Fayetteville-Manlius C.S.D.  Simply put, this document would not exist without the district’s generous support. The syllabus is solely intended for use in the F-M C.S.D.’s high school science program or as a reference work for district employees.  

 

Background

            Astronomy has been taught for many years at the high school level but lacked a specific syllabus. There was a need for this document as the course changed as often as the person that taught it. Since the science department already offers Cosmology (I & II) there was also a compelling need to make sure that this course met a different need of the student population. Thus Observational Astronomy was born. This course is intended to facilitate an understanding of the universe to students that have a minimum background in high school math and/or science.

            Prior to devising this curriculum a good deal of time was spent researching national standards. For an edifying experience, all educators of science are encouraged to do the same at the following web sites:

• National Science Education Standards

http://www.nap.edu/readingroom/books/nses/html        

• Science For All Americans

http://www.project2061.org/tools/benchol

Please peruse the resource list for other sources used in assembling this syllabus. For ease of use, portions of this syllabus have been written intentionally to be copied off and given to students.

 

Prerequisites

            Observational Astronomy is a half credit science elective open to sophomores, juniors and seniors that have successfully completed Physical Setting: Earth Science or similar course, and earned a math credit. Completion of a drawing oriented art course is highly desirable. This course is closed to freshman.

 

Who Should Take This Course

            This course is designed to be a project oriented, descriptive course for students that have concentrations in disciplines other than science. Although Observational Astronomy uses at times, basic algebra and some geometry the use of math to quantify problems or concepts has been minimized. Students pursuing a four-year science and math sequence should enroll in Cosmology 1 and 2. Students that insist on taking both astronomy and cosmology should realize that overlapping of some content is inevitable.

            It should also be noted that this half credit course meets every other day for one year.  Mature students, able to plan their time and deal with a somewhat irregular class schedule, as well as an inquiry-oriented curriculum, will do well.

 

What Will We Do In Class?

The topics in this class are based on extensions of content found in Physical Setting: Earth Science as well as National Science Education Standards. The course is inquiry oriented. Students will be presented with an idea or open-ended problem in which they will be given class time to investigate. The instructor’s role is to facilitate the student’s experience. At times, due to the nature of the subject matter, classes will involve a lecture or presentation in order for students to develop prior knowledge from which to launch their inquiries from. At other times students will perform the same scientific activities that astronomers perfrom. There is a midterm and final exam, parts of which will involve the planetarium. Other methods of assesment will involve quizzes, projects, models, journals, short papers and conferencing. Homework will be recording observations into a journal as well as assigned readings from the text or the internet.          

Note the following: we meet every other day and as a consequence a 10 week quarter grade is based on 5 weeks of actual class time. Any missed assignment will have an impact on grades. 

 

What This Course Is About

            Ideally, students exiting this course will be akin to amateur astronomers able to find their way around the night sky. They will have practical knowledge of telescopes and binoculars and have a general understanding of the organization of the universe. The course is intentionally organized around the high school planetarium. As a consequence of these outcomes, Observational Astronomy has a somewhat unusual organization:

 

Units                           Description                                                    

Prologue – on the difference between science and pseudoscience.

Observations – doing what astronomers do.

Constellations – Identifying patterns on the celestial sphere.

Technology –    using telescopes & binoculars to improve observations.

Models of the Universe – to understand the historical process of our modern understandings.

Origin of the Solar System – an exercise in observation and inference.

Stars – their life cycles and characteristics

Galaxies – basic morphology & classification and the search for dark matter

Earth Moon System – the cosmic effect of earth’s motions; lunar phases, eclipses

Comparative Planetology – interpreting the surface features of other worlds.

Space Exploration and SETI – “to boldly go where no one has gone before.”

Amateur Astronomy and Digital Imaging – how to observe, image & process celestial objects from your backyard.

 

In this approach, students will develop in September a set of basic perceptions or experiences of the night sky that they gradually enrich through out the year.

 

Observational Astronomy Syllabus

 

Content

 

Prologue: Science and Pseudoscience

 

What is Science?

Scientists understand that perception is not always reality. Science is a way of thinking based on two assumptions:

 

P.1       Repeatability - events, relationships, and observations must be repeatable in order to be considered valid or an actual part of reality.

 

P.2       Present knowledge may be disproved in the future using better tools, techniques, equations, etc.  That is to say, science is a body of knowledge that is potential disprovable.

Rarely are theories elevated to the level of a “Law.” We assume a reasonable confidence, based on a compelling body of observations, that a theory is correct. However, whenever exceptions or patterns are found that cannot be adequately explained by theory or model, scientists adopt a skeptical position as to the validity of previously accepted paradigms. It is understood that the ideas and concepts taught in this course today may be disproved in the near or far future. This is the defining characteristic that sets science apart from all other branches of thought.

 

Pseudoscience

Students will examine the evidence for astrology and UFO activities and apply the two basic assumptions of science (repeatability and disprovability) to determine the validity of their claims.

 

P.3       Astrology claims that people are influenced by the positions of celestial objects at the moment of their birth. Astrology has a history that can be traced back through the Greeks to the Babylonians.

 

A.     Astrologers use the names of constellations in the zodiac to represent signs.

 

B.     Sun signs are based on the position of the sun relative to a constellation at the moment of birth.

 

C.     Astrology was practiced first by the Babylonians and latter by the Greeks. Ptolemy “codified” astrology in the tetrabiblos.

 

D.     Sun signs used today no longer match the calendar position of the Sun in the zodiac due to the precession of the Earth.

 

P.4       Historically, UFOs were first reported in various media outlets shortly after the end of World War II.

 

A.     Evidence of UFOs is limited to eyewitness reports, and recordings such as photographs and video. Currently there is no physical evidence of extraterrestrials (aliens) or extraterrestrial artifacts.

 

B.     There is a large quantity of published speculation regarding UFOs by a broad spectrum of authors, few of whom are trained scientists.

 

C.     The vast majority of UFO sightings have been determined to be hoaxes. Recent brain research (Persinger, et al.) can account for all alien abduction phenomena.

 

Assessment

1.         Students will determine the authenticity of astrology by applying the tests of repeatability and disprovability. Given two sets of unlabeled horoscopes, students will try to match the astrological prediction to the day they are having. Students will then interview each other to determine the approximate number of correct response and therefore the predictive power of astrology. Students will compare this to other types of predictions (e.g., weather forecasts).

 

2.         Students will read an article reprinted from Skeptic magazine outlining 12 questions to ask an astrologer.

 

3.         Students will write a brief position paper on why astrology is popular and why people consult with astrologists.

 

4.         Students will examine the evidence surrounding UFOs and alien abductions (NOVA: Are We Alone?) and determine the most probable causes of these phenomena.

 

Unit 1: Basic Astronomical Observations

 

“Humans have never lost interest in trying to find out how the universe is put together, how it works and where they fit the cosmic scheme of things. The development of our understanding of the architecture of the universe is surely not complete, but we have made great progress. Given a universe that is made up of distances to vast to reach and of particles to small to see and too numerous to count, it is a tribute to human intelligence that we have made as much progress as we have in accounting for how things fit together. All humans should participate in the pleasure of coming to know their universe better”                  Science For All Americans

 

1.1       Astronomers record observations of celestial objects and events.

 

Students will weekly sketch/record into their journals the following observations:

A.     Location and time of the Sun at sunrise or sunset on the horizon relative, to due east or due west. Never look directly at the Sun.

B.     Phase of Moon and relative location in the sky.

C.     Position of planet Mercury, Venus, Mars, Jupiter and Saturn relative to a constellation.

 

            During the year, students will also sign out a set of binoculars with a tripod to make observations at home. During this time they will attempt to record observations of lunar features and deep sky objects. At no time may binoculars be used to observe the Sun. Looking at the Sun directly will damage your eyes and may cause blindness.

 

Accommodations will be made for stretches of cloudy weather! Examples of journal entries will be modeled. Each entry must have: the date, time (local time or GMT) and location; a brief descriptor on the seeing conditions/atmosphere; an indication of one of the cardinal directions (north, south, east, west) and a sketch of the object. Observations can be made from any location on Earth but the “darker” the sky the better. Students living in wooded areas will need to find open spaces. Students athletes will need to carefully plan their time when signing out the binoculars. If sky conditions do not permit observations during the sign out period then students must choose a new date later in the school calendar. The minimum expectation is that students will make an observation once every 7 days.

 

Assessment

            All journals will be collected and graded every 5 weeks on a scale of ten and count as a homework grade. Naked eye observations in journals will be conferenced with students on a regular basis and graded using a rubric. Binocular observations will be turned in the day the equipment is returned and will be graded separately from the journal. All students must have submitted binocular observations by the first school day in May. This requirement (journal and binocular observation) is part of the final exam. The expectation is that students will go outside on their own and do what astronomers do: look at the sky and record their sensory perceptions as accurately as possible. Students lacking in drawing skills are encouraged to enroll in studio art but will not penalized on aesthetics. In this case the commitment and effort of the student will have greater merit in grading than verisimilitude. During conferencing it will be expected that students can discuss their observations. As their ability to understand the night sky improves, their ability to discuss their journal entries should show more depth.

 

Unit 2: Constellations

 

2.1       What are the origins of star patterns called constellations?

1. Approximately 4000 years ago, four original constellations in the zodiac were used as seasonal markers. Cultural myths were attached to the patterns to aide in memorization.

 

2. New constellations were required every 1000 years because Earth’s precession caused the position of the Sun to appear to shift relative to the constellations.

 

3. Current boundaries devised in 1875 by Gould & Delporte officially adopted in 1935.

 

• Ascending Node - March equinox - ecliptic passes above celestial equator.
• Descending node - September equinox -ecliptic passes below celestial equator
• Solstice - day at which ecliptic and equator are farthest apart.

 

Reading assignment: Sky and Telescope article on the origin of the zodiac.

 

2.2       How are constellations and stars named?

 

A.     48 ancient constellations use Latin names based on Claudius Ptolemy.

 

B.     38 “modern” constellation names (still in Latin) were invented between the 15th and 18th centuries.

 

C.     Their are 88 modern day constellations. Students do not need to memorize the names of all the constellations.

 

D.     Names of the brightest stars are primarily Arabic in origin, the meaning of which is typically associated with the constellation it’s found in.

 

E.     All stars in a constellation are assigned a Greek letter in order of greatest to least magnitude (alpha Leonis; Beta Leonis).

 

Students do not need to memorize all the Arabic, Greek and Latin names.

 

2.3       Seasonal position of constellations change due to precession and to a lesser extent proper motion of the Sun and stars.

 

A.     Precession causes constellations to appear to forward shift by 1 degree every 71. 6 years along the ecliptic.

 

B.     Precession has a short term and long term effect on observing.

 

·        Star maps need to be updated regularly to be accurate.  North and south lines of constellation boundaries slowly become diagonals. For this reason, star maps are given dates.

·        Node locations change on a millennial basis.

 

2.4       Stars have proper motion.

 

A.     Nearby Constellations, i.e. Ursa Major, are more affected by proper motion than distant ones.

 

B.     The change in star position due to proper motion occurs over millennia.

 

C.     Barnard’s star moves significantly over decades.

 

D.     The Sun’s proper motion is in the direction of Vega.

 

2.5       Asterisms are easily recognizable star groupings within a constellation.

 

·        Big Dipper,

·        Tea Pot

·        Orion’s Belt

 

2.6       How can constellations be modeled?

 

A.     2 -d on the celestial sphere

 

B.     3-d if actual distances are known

 

2.7       What tools can be used to locate constellations and stars?

 

A.     Planispheres are paper models of the celestial sphere. Planispheres will be used to determine the ecliptic and the seasonal changes of the sun’s position relative constellations.

 

·        Students will construct and use their own planispheres or star finders for use at NYS latitudes.

 

·        Distances between stars are distorted at the outer edge of the planispheres

 

2.8       All constellations can be located given their right ascension and declination

 

A.     Declination is the number of arc degrees above or below the celestial equator.

 

B.     Distance along the celestial equator is measured in 24 hours of right ascension.

 

 

 

Addendum

Magnitudes

Hipparcus (190 to 120 B.C.E.) was a Greek astronomer and mathematician that is credited with many discoveries including: trigonometry, the length of a year to within 6 minutes, the precession of the equinoxes, and the first accurate star catalog containing 850 stars. His system of ordering the brightness of stars is still used today.

 

The Brightness System or Stellar Magnitudes

 

1.                  Apparent – Magnitude – how bright an object seems to be compared to others.

2.                  Absolute magnitude – how bright an object actually is.

 

Apparent Magnitudes

• 1^st magnitude stars – the brightest
• 2^nd magnitude stars – the second brightest
• 6^th magnitude stars – the faintest light seen with one’s eyes at a light pollution free site using averted vision

 

Ptolemy copied the system (AD 140) and his book became the standard text for astronomers for the next 1400 years. At this time it was accepted that stars were objects at a fixed distance and position  and that no stars existed that were dimmer than 6^th mangitude.

 

Galileo  - used the telescope for astronomical purposes and discovered stars fainter than 6^th magnitude.  He created seventh magnitude stars.  This opened the floodgates making the magnitude system open-ended. 

 

• Binoculars (10 x 50)     can see down to 9^th magnitude.
• 6” reflector telescope    can see down to 13^th mag.
• Hubble Space telescope (HST) can see down to 30^th mag.

 

The apparent magnitude system was ok prior to telescopes but makes little sense now.  Keep in mind that the larger the number the fainter the object.

 

Along comes the Logarithm Boom of the 1850’s…J

A first magnitude star is about 2.5 times brighter than a second magnitude star (logarithmically). That is to say the apparent magnitude system is not linear.

More difficulties… imagine four stars in the sky  with the following apparent magnitudes:

 

2.0                                           3.0                               4.0                  

 

The brightness of a 3.0 star does not appear to be halfway between a 2.0 and a 4.0 star.  The 2.8 magnitude star truly looks like the half waypoint in brightness between the 2.0 and the 4.0 stars. This created problems for scientists that like accurate measurements.

 

More fun from the 1850’s…

            Astronomers realized that some stars are brighter than “1.”  So the astronomers began to reclassify the brightest celestial objects:

0 Magnitude stars

Rigel (Leo)

Capella (Auriga)

Arcturus (Bootes)

Vega (Lyra)

 

Negative Magnitude Objects

Sirius  = -1.5 (-1.46)

Venus = -4.4 (peak brightness, it varies a bit)

Full Moon = -12.5

Sun = -26.7

 

Today, precise apparent magnitudes are determined by using photometers and colored filters. Apparent magnitudes have a drawback in that they are how bright a star appears to be which is greatly affected by a stars proximity to the solar system. For example: Sirius appears to be the brightest star  (northern hemisphere) because it is close to us (8.6 light years away). Absolute magnitudes is how bright a star really is.  .

 

To determine the absolute magnitude of a star we mathmatically take all the stars, line them up in a row and stand back 10 parsecs (32.6 light years). Two examples: Sun = 4.85; Rigel = -8

 

In science literature and upper and lower case “M” is used to distinguish between absolute and apparent magnitudes, repsectively.

Absolute magnitudes “M”

Apparent magnitudes “m”

For Comets and Asteroids – magnitude is determined by how bright they would appear at one astronomical unit (1 A.U. equals 150,000,000 km or the average distance from the Earth to the Sun).

 

What you can Realistically See:

Apparent Magnitude                             Location

6.4                                                                                                              3000 or so visible stars; must be away from all street lights; central Adirondacks, Four Corner States, etc.; Milky way is very bright

5.5 – 4.4                                              Rural, near a city (e.g. Fabius, DeRuyter); Milky Way still visible at 5.0

 

4.4 – 3.5                                              Cities, urban areas (F-M = 4.0 to 5.0); only the brightest stars are visible(about 300 or so); no Milky Way

 

 

 

Unit 2 Assessments

 

I.      Constellation Identification

            Students will identify (organized by seasons), stars and deep sky objects in the planetarium and if possible during night labs. The following identification list is sorted by seasons and that is the order in which students should learn them. Several times during a particular season students will use the planetarium to learn their list and finally be assessed. The summer list should be broken up and learned at the beginning and end of the school year.

 

Fall

Constellations               Star                                          Deep Sky Object                                

Aquarius

Pisces

Aries                            Hamal

Pegasus                        Alpheratz, Algenib, Markab

Andromeda                                                                  M31

Cassiopeia

Perseus                                   

Piscus Austrinus            Fomalhaut

Cetus

Eridanus

Cepheus

Winter

Constellations               Star                                          Deep Sky Object                                

Taurus                          Aldebaran                                Hyades & Pleidades

Gemini                          Castor, Pollux

Orion                           Rigel & Betelgeuse                   M42

Canis Major                 Sirius

Canis Minor                 Procyon

Auriga                          Capella

 

Spring

Constellations               Star                                          Deep Sky Object                                

Cancer                                                                         Beehive Cluster/M44

Leo                              Regulus, Denebola

Virgo                            Spica

Hydra

Crater

Corvus

Ursa Major                  Merak & Dubhe

Ursa Minor                   Polaris & Kochab

Draco

Bootes                         Arcturus

Corona Borealis

Hercules                                                                       M13

Summer

Constellations               Star                                          Deep Sky Object                                

Libra

Scorpio                        Antares

Sagittarius

Capricorn

Cygnus             Deneb

Lyra                             Vega

Delphinus

Aquila                          Altair

Capricornus

 

II        Adopt a Constellation

Part 1.              Students will adopt one of the following constellation in or near the plane of the Milky Way.

 

Orion

Gemini

Taurus

Capella

Perseus

Cassiopeia

Cygnus

Aquila

Ophiuchus

Sagittarius

Scorpius

Lupus

Centaurus

Circinus

Crux      

Carina

Vela

Puppis

Canis Major

Tucana

Dorado