Presentation on theme: "Reach for the Stars Presented by Linder Winter National Event Supervisor E-S Rules Committee Chair."— Presentation transcript:
Reach for the Stars Presented by Linder Winter National Event Supervisor E-S Rules Committee Chair
Reach for the Stars Part I: Basic Event Information
Description Students will demonstrate an understand- ing and basic knowledge of the properties and evolution of sun-sized and massive stars, open clusters and globular clusters, and normal and star-forming galaxies.
Note: “Reach for the Stars” is now solely a “stars” event and, as such, will no longer include: 1. location and identification of planets on star charts, etc. 2. the term “zodiac” to avoid the pseudo-science of astrology. 3. or references to asterisms.
Event Parameters The only resource permitted is one 8.5” x 11.5” single or double-sided sheet of computer-generated or handwritten notes per team. Notes may include graphics, tables, and/or text.
Event Parameters Suggested information to include on the resource sheet for each star: a. Name. Example. Sol b. Classification. G2V c. Evolutionary stage. Main sequence d. Constellation e. RA/Declination, i.e. location f. Unique characteristics, if any
Event Parameters Suggested information to include on the resource sheet for each Deep Sky Object: a. Name b. Constellation c. Messier number, i.e. M1, M13, etc. d. Kind of object: SNR, Globular cluster, etc. e. RA/Declination (for location) f. Thumbnail image g. Unique characteristics, if any
The Competition The event is divided into two parts. Notes may be used in both parts.
The Competition Part I: Participants will be asked to identify the stars, constellations, and deep sky objects included in the lists below as they appear on star charts, H-R diagrams, portable star labs, photos, or planetariums, and be knowledgeable about the evolutionary stages of all stars and deep sky objects. (Participants must bring a flashlight with a red filter and a clipboard unless they have been informed that the event will not take place in a planetarium or a portable star lab.)
Stars The stars in the list were chosen to repre- sent the various stages in the lives of stars. A few of the stars and deep sky objects on the list are not visible from the northern hemisphere. Example: there are no similar features to the Magellanic Clouds in the Northern skies.
Constellations Constellations have been included 1. for historical purposes. 2. for ease of locating specific objects in the sky. 3. and for those individuals who enjoy locating them and learning their accompanying tales. Coaches should emphasize that constellations are imaginary groupings of stars with historical and literary importance, but limited scientific significance.
Stellar Classification Standard means to record the classifi-cation of a star. Example: Earth’s sun = G2V 1. Letter of class – O, B, A, F, G, K, M 2. Temperature number – 0 to 9 3. Luminosity category – Ia, Ib, II, III, IV, V, VI, VII (Not always included. It’s proper to refer to the sun as a G2 star.)
Spectral Classification For Earth's star, Sol, a G2V star: 1. Class – G 2. Relatively hot – 2 3. Main sequence star – V
Stellar Classification Each star class is divided into 10 sub- classes, ranging from 0 (hottest) to 9 (coolest).
Spectral Classification Luminosity Classes are designated by Roman numerals I thru VII, in order of decreasing luminosity: Ia (most luminous supergiants) Ib (less luminous supergiants) II (luminous giants) III (normal giants) IV (subgiants) V (main sequence and dwarfs) VI (subdwarfs) (VI stars are not always included.) VII (white dwarfs) (VIII stars are not always included.)
Spectral Classification The color of a star depends on its temperature Red Stars are Cooler Blue Stars are Hotter Spectral Classification Classify stars by their spectral lines Spectral differences are due mostly to temperature, not composition. Spectral Sequence (Temperature Sequence): O B A F G K M L T
Spectral Classification The traditional mnemonics for remembering the spectral types are based on the old Harvard OBAFGKM system. Harvard (1920s): Oh Be A Fine Girl, Kiss Me Berkeley (late `60s): Oh Buy A Fine Green Kilo Man Caltech (late `70s): On Bad Afternoons Fermented Grapes Keep Mrs. Richard Nixon Smiling
Reach for the Stars Part II: Information for Students
Stellar Evolution of Stars Formation in a stellar nursery … through birth … each life stage … and final product – (white dwarf, neutron star, black hole).
Star Clusters: Definition Gravitationally-bound collection of stars that formed from the same gas cloud.
Open Clusters Image: WIYN Telescope, Kitt Peak 1. Contain a few (typically tens to thousands of) young stars 2. Individual stars are easily resolved
Open Clusters Credit: AURA, NOAO, NSF 3. Open clusters are collections of hot, recently formed stars found preferentially in the spiral arms of the galaxy. 4. Stars within open clusters eventually disperse.
Globular Clusters Image: Hubble Space Telescope 1. Are found in the haloes of galaxies 2. Contain from tens of thousands to millions of ancient stars crowded into a more or less spherical volume of space.
Globular Clusters Image: Sonoita Observatories 3. Their central density is sufficiently high that individual stars cannot be resolved from earth- based telescopes
Spiral Galaxies The spiral galaxy NGC Disk-shaped, usually with a bulge at the center and arms spiraling outwards 2. Tend to contain more middle-aged stars along with clouds of gas and dust
Spiral Galaxies Image courtesy Richard Crisp Spiral galaxies contain large concentrations of gas and dust. The spiral arms are waves of star formation swirling around the galaxy. New stars are hot and bright. They light up the gas and dust in the arms.
Elliptical Galaxies NOAO/AURA/NSF 1. Contain older stars and very little gas and dust 2. Can be different shapes ranging from round, to flattened, elongated spheres. 3.Orbits of stars within elliptical galaxies are in random directions
Eliptical Galaxies Elliptical galaxies contain modest amounts of cool and warm gas, though not as much as found in spiral galaxies There are generally not enough gases to support much star formation. The Giant Elliptical, M87
Galactic Types & Structure Irregular galaxies 1. Poorly-defined structures 2. Have lots of young stars, dust and gas. 3.Show evidence of extensive star formation Image courtesy of Richard Crisp.
Constellation: Ophiuchus Star: Bernard’s Star Bernard’s Star is currently the second closest star to the Sun, at 5.96 light years (if you count the 3 stars of Alpha Centauri as one star). It also has the highest known proper motion, i.e., it is moving relative to the Sun at a greater speed than any other star. In about 8,000 years, its speed and direction will make Bernard's Star the closest star to the Sun.
Milky Way Galaxy Copyright Lund Observatory
Reach for the Stars Part III: Instructional Activities
Stellar Bingo: An Introductory Activity Note: This activity has been included on your Coaches Clinic CD.
Star Clues This activity is also on the Coaches Clinic CD. Introduces students to the H-R Diagram through a challenging activity requiring students to complete a chart from clues.
Reach for the Stars Practice Exam Note: This practice exam has been included on your Coaches Clinic CD. The exam uses a set of “Stellar Evolution” images that may be requested from the Chandra X-ray Center.
The Game of SPACE S = Stars P = Planets A = Astronomy C = Constellations E = Exploration
STELLAR JOURNEY: The Game Participants gather mass and time to apply to three stars of varying mass. The three stars are born, live their lives, and die as either white dwarfs, neutron stars, or black holes.