INDEPENDENT PROJECT: The Spring Night Sky

Transcription

1 INDEPENDENT PROJECT: The Spring Night Sky Your Name: What is the difference between observing and looking? As John Rummel said to the Madison Astronomical Society, January 11, 2002: Looking implies a passive exercise whereas observing is active and purposeful. The looker glances for a moment, and then moves on. The observer studies, considers, examines, and lingers. A good exercise to illuminate the difference is to watch somebody passively look at an object or scene, and then watch somebody who is trying to sketch or otherwise make a written record of the scene so that he or she can describe it to somebody else. The act of sketching or recording what is seen requires close observation and examination. Amateur astronomers, who have made a sketch of the planet Jupiter, or of a section of the lunar surface, know the difference. In all observing projects in this course, the main goal is to practice observing, rather than looking. In this exercise, The Spring Night Sky, the objectives are to: 1. Observe, identify, and locate stars. This includes locating and naming several specific star, and measuring (with hands and eyes) angles between stars. 2. Study constellations and asterisms. This involves identifying groups or patterns of stars. 3. Identify and locate any visible planets (which can be seen without a telescope). 4. If the moon is visible, identify its phase and locate it. Tips on being prepared for observing: Observe from a dark, elevated site with a wide, unimpeded view of the sky. Streetlights and house lights nearby reduce your ability to see the stars. The goal is to have no artificial lights in sight and as high an elevation above sea level as possible. Do not observe with any lights on nearby, including streetlights. Get away from them. Preserve your night vision. It takes the eyes minutes to become dilated and achieve best night vision. A white beam from a flashlight or car headlights will destroy your night vision and you will not be able to see as many stars. Soft red light does not ruin your night vision. To see things like this page in the dark while observing the night sky, use a red flashlight or LED. Put a red balloon over the end of a flashlight, or buy a key-chain red LED light for two or three dollars at a local store. Dress appropriately to stay warm and comfortable while standing outside for at least an hour. It will be colder at night than during the day. Wearing inappropriate clothing for nighttime sky-observing will likely cause you to become chilled, which could curtail your observing session before it should end. Take a camera to meet the photography requirement. All the drawings must be real drawings you made while outside under the stars. Draw only what you actually see. Do not copy constellations from star charts, and DO NOT The Spring Night Sky Spring 2014 Page 1

2 draw lines connecting the stars in your constellation drawings. Any constellation drawn with lines connecting its stars earns zero points. Three different nights is the minimum requirement for how many nights you observe the night sky and record your results for this project. REPORTING YOUR OBSERVING RESULTS For each night you observe you MUST create a page that contains the following information: 1. Date 2. Times (start time and end time) 3. Location (be specific, give an address or a physical description of where your observing site is located) 4. Weather (be specific, give the temperature and describe the cloudiness, haziness, windiness) 5. Quality of seeing (excellent, good, moderate, or poor, and why) 6. Labeled drawings of constellations/stars/planets (see below for targets). a. Each drawing must include an indication of the horizon - sketch hills/houses/trees, or if looking high in the sky draw an arrow pointing down toward the horizon stating which compass direction the arrow points. 7. Each drawing must have your name and the date on it. The Photography Requirement: A. At least two of your constellation drawings must be accompanied by a photograph you took of that part of the sky during that observing session. B. At least one of your planet drawings must be accompanied by a photograph you took of that part of the sky during that observing session, in which the planet is visible. C. Any moon drawing (required if the moon is visible) must be accompanied by a photograph. D. The photographs should be printed on (or glued upon) regular notebook-size pages, and should be date-stamped. (If your camera does not have the date-stamp option, write the date and time on the page with the photo.) NOTE: If you find it difficult to get the stars to show up in your photographs, then you could try the following: 1) If your first attempt at night sky photographs fails, try again, perhaps with a borrowed camera, or, if you are using a smartphone, use an app that allows you to take nightsky or long-exposure photographs. 2) Try taking photographs of the brightest celestial objects the moon, the brightest star, or the brightest planet. At least those should show up in your photographs. The Spring Night Sky Spring 2014 Page 2

3 OBSERVING TARGETS AND TASKS 1. The circumpolar constellations. On clear nights, the circumpolar stars are always visible from mid-latitudes (like Wenatchee) as well as higher latitudes. In the northern sky, locate the star Polaris and the constellations Ursa Minor (which includes the Little Dipper asterism), Ursa Major (including the Big Dipper asterism), and the constellation Cassiopeia. Draw a sketch of the stars you see defining the circumpolar constellations. Indicate some of the compass directions (such as arrows to S or W) on your drawing. o On every drawing, in fact, you need to put at least one labeled compass direction arrow. Each drawing also needs an indication of which direction the nearest horizon is as well. If the area you are drawing is close enough to the horizon, sketch in some of the horizon features at the bottom of the drawing. Label the Big Dipper, the Little Dipper, and the stars Polaris and Mizar. Label the constellation Cassiopeia (write its name down in it or next to it). 2. Gemini Draw and label the constellation Gemini (the Twins). Label the bright twin stars correctly as Pollux and Castor. Note: Do this during the first month of the quarter, early in the evening. By June, Gemini will be setting before it gets dark. Note: Jupiter will be in the constellation Gemini this spring of 2014, and will be brighter than any star. Jupiter is one of your planet-hunting targets (see #8, below). Remember, in all your sky drawings, to put in one or more labeled compass direction arrows and an indication of the direction to the nearest horizon. In addition, if you are drawing an area of the sky near the horizon, draw some of the things on the ground you see along your horizon, at the bottom of your drawing. 3. Hercules Draw the constellation Hercules and label it Hercules. 4. Virgo Draw what you can see of the constellation and label it (write the name, Virgo, in or next to the constellation). Label its brightest star, Spica. Note: You will see the planet Mars in Virgo during Spring 2014, brighter than any star in the constellation. Mars, with its distinctly reddish tone, is one of your planet-hunting targets (see #10, below). Note: On the night of April 14, 2014, the moon will be in the vicinity of Virgo and Mars, and the moon will pass deep into the Earth's shadow, causing a total lunar eclipse. Although the moon remains visible during a lunar eclipse, it will turn dark and ruddy. The deeper into Earth's shadow it goes, the darker the moon will get. If clouds do not envelop the sky that night, you should watch the eclipse of the moon. There is a lot to learn from it. There will be an extra-credit assignment for observing the lunar eclipse. The Spring Night Sky Spring 2014 Page 3

4 5. Leo Draw and label the constellation Leo (the Lion). Label the brightest star in Leo, Regulus. 6. Boötes Draw and label the constellation Boötes (the Bear Hunter). Label the brightest star in Boötes, the reddish star Arcturus. 7. Libra Draw and label the constellation Libra (the Balance). Libra has has no very bright stars, so don't label any of its stars. Note: You will see the planet Saturn in Libra during Spring 2014, far brighter than any star in the constellation Libra. Saturn, with its famous rings (which you need a telescope or very strong binoculars to see), is one of your planet-hunting targets (see #10, below). 8. The Big Dipper Asterism as a Locator. This needs to be a separate drawing from the one you make for the circumpolar constellations (above). It needs to be drawn on a different night. Draw the Big Dipper Asterism. Label the stars of the Mizar and Alcor (Mizar is the brighter of those two; Alcor is right next to Mizar, and if you have strong eyesight you will be able to see Alcor alongside Mizar). On your drawing of the Big Dipper, draw an arrow through the pointer stars extending in the direction of Polaris, the North Star. Label the tip of the arrow to Polaris. Draw an arc extending through the handle of the Big Dipper and a bit beyond, and put an arrow on the end of it labeled, follow the arc to Arcturus. 9. The moon you are likely to see the moon on at least one of the nights you observe. If so, you are expected to take advantage of the opportunity to include it in your observing results. If the moon is out: Draw the moon. Name its phase. Give its altazimuth coordinates. State which constellation it is in. Photograph it. 10. The Planets. Observe, draw and label at least three of the following planets: Jupiter, Mars, Saturn, Venus, and Mercury. Those five are the only planets easily seen with the naked eye. On your drawings: Label each planet. Draw the brightest stars you can see in the vicinity of the planets. Label the constellation each planet is in. Give the altazimuth coordinates for each planet The Spring Night Sky Spring 2014 Page 4

5 General Notes on Finding Planets The word planet means wanderer. This is because, as seen from Earth, the planets lowly wander across the fixed constellations of the zodiac. As the weeks and months go by, the locations of the planets relative to the background stars and relative to the sun keep changing. This is because the planets all revolve around the Sun in orbital planes close to the ecliptic plane. (The ecliptic plane is the plane of Earth s orbit around the Sun.) The stars, because they are so far away, will not appear to change their positions in the sky in your lifetime at least not enough for you to detect with your naked eye. Planets often appear brighter and twinkle much less than stars do, although that is not always the case, depending on how big the planet is, how far away it is, how high it is in the sky, and the weather. Spring 2014 Planet-Finding Notes Spring 2014 will be GREAT for seeing the planets. Venus: The planet Venus takes on the role of the morning star" during the first half of Spring Quarter This means that you will have to get up before the crack of dawn to observe the planet, a beautiful apparition in the eastern sky, far brighter than any star in the sky around it, the last "star" to wink out as the sun rises. The earlier in the quarter you look for Venus in the pre-dawn sky, the higher up and brighter it will be. If you wait until too late in the quarter, Venus will be too close to the Sun for you to see. Jupiter: As mentioned above in the sequence of constellations, Jupiter is in Gemini this spring. You need to go out early in the evening, soon after dark, to see Jupiter. As the evening proceeds, Jupiter will set in the west. Saturn: The ringed planet will be high and bright in the night sky this spring of Saturn will rise in the east soon after dark each night, and will best be seen in the middle of the night, shining high and bright in the southern sky. On May 10, Saturn will be at opposition, its closest approach to Earth for the year, opposite from the Sun in our sky. This means Saturn will be up all night and very bright. Because of the angle at which the rings of Saturn are oriented relative to the Sun and Earth, the planet will be brighter (reflecting more total sunlight during its closest approach to Earth) than it has been in years. Mars: As mentioned above, Mars will be in the constellation Virgo this spring. You can see Mars in high up the evening sky after the sun sets. Mars will be up late each night before it drops down below the western horizon. The Spring Night Sky Spring 2014 Page 5

6 Date and Time: Polaris azimuth: altitude: Date and Time: Arcturus azimuth: altitude: Date and Time: Castor azimuth: altitude: Date and Time: Pollux azimuth: altitude: Date and Time: Spica azimuth: altitude: Date and Time: Regulus azimuth: altitude: Date and Time: The moon azimuth: altitude: Date and Time: The moon azimuth: altitude: Date and Time: Jupiter azimuth: altitude: Date and Time: Venus azimuth: altitude: Date and Time: Mars azimuth: altitude: Date and Time: Saturn azimuth: altitude: Date and Time: Angle from Jupiter to Mars angle: Date and Time: Angle from Mars to Spica angle: Date and Time: Angle from Saturn to Arcturus angle: Some essentials (i.e. requirements) on successful night sky observing projects: Do not draw lines connecting stars in your constellations. Only draw what you actually see in the sky, along with some names to label things (as instructed), and some compass direction arrows. Include some horizon features on drawings you make that show stars located in the lower half of your sky, to orient your sketch and those who look at it later. Buildings, trees, or hills are typical horizon features that you can sketch the outline of along the bottom of a drawing. The Spring Night Sky Spring 2014 Page 6