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 observe, rather than just look. In this exercise, The Spring Night Sky, the objectives are to: 1. Observe, identify, and locate stars. This includes locating and naming a number of specific stars, and measuring (with hands and eyes) the angles between stars. 2. Study constellations and asterisms. This involves identifying groups or patterns of stars. 3. Identify and locate any visible planets (those which can be seen with the naked eye). 4. If the moon is visible, identify its phase and locate it. Write down the date, time, place, and sky condition each time you observe. Draw the stars, constellations, and planets that you see, as dots on a page, while you observe them. Measure coordinates and angles yourself, while you are out there under the night sky. DO NOT DRAW ANYTHING ON YOUR MAPS THAT YOU DO NOT OBSERVE WITH YOUR OWN EYES. Tips on being prepared for observing: Observe from a dark, elevated site with a wide, unimpeded view of the sky. The goal is to have no artificial lights in sight and be as high 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 night vision. A white beam from a flashlight or car headlights will ruin 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 red 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 an hour. It may be very cold outside. Do not let insufficient clothing affect your observing session. Take a camera to meet the photography requirement. The Spring Night Sky Spring 2015 Page 1

2 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 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. This information can go on the same page as the drawing, or the first drawing you make that night if you make more than one constellation drawing that night: 1. Date (each and every page of night sky drawings must have a date on it) 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 three 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. At least one moon drawing (at least one moon drawing is required) must be accompanied by a photograph in which the moon is visible. 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.) Add a caption stating what is depicted in the photograph (what the camera was aimed at when you took the photograph). 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 2015 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) and from higher latitudes closer to the earth s North Pole. In the northern sky, locate the star Polaris and the constellations Ursa Minor (which includes the Little Dipper asterism), and Ursa Major (including the Big Dipper asterism.) Draw a sketch of the stars you see defining the circumpolar constellations. Label the Big Dipper, the Little Dipper, and the stars Polaris and Mizar/Alcor. o Note: Only label Alcor if you can see it, a faint star right next to Mizar. On a dark, clear night, from a dark observing site, look for Cassiopeia in the circumpolar sky. Draw its visible stars and label the constellation. Cassiopeia will be low in the north after darkness falls. You can see Cassiopeia better, higher up in the sky, in the last hour of darkness before dawn. 2. 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 made either later the same night or else on a different night. Draw the Big Dipper Asterism. 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 arcing arrow extending through and beyond the handle of the Big Dipper, and label it arc to Arcturus. (Note: For many more ways to use the Big Dipper, and Orion, to find constellations, check out the web page 3. Orion This must be completed in April, while Orion is still up in the evenings Draw and label the beautiful, bright constellation Orion, which is one of the constellations that dominates the winter sky at night, and is still visible during the first half of spring night-times. Label the brightest stars in Orion: Betelgeuse and Rigel. Label the belt of Orion, which consists of three relatively bright stars in a line. 4. The Winter Triangle Must be completed in April, while these stars are visible Draw, label, and measure the three stars of the Winter Triangle Sirius, Procyon, and Betelgeuse. Indicate which way is north (N) and which way is east (E) on your drawing. Draw features (buildings, trees, etc.) you see on your southern horizon at the bottom of the drawing and label it southern horizon. (You should indicate the horizon along the bottom of any night-sky drawing you make of areas adjacent to the horizon.) The Spring Night Sky Spring 2015 Page 3

4 Use altazimuth coordinates for measuring where these stars are in your view of the night sky. Write your measurements in the table for altazimuth coordinates, below. Altazimuth coordinates are altitude and azimuth. Altitude is the angle above the horizon, which ranges from 0 degrees (at the horizon) to 90 degrees (at the apex). Your fist, held at arm s length with your elbow locked and your thumb inside your fist spans about 10 degrees of your field of view. Azimuth is the compass direction of the point on horizon directly below the object. Azimuth values range from 0 degrees (due North) to 360 degrees at which point due North is reached again and the azimuth value goes back to 0 degrees. The azimuth value for due East is 90 degrees, due South is 180 degrees, and due West 270 degrees. Around each star of the Winter Triangle, draw the other stars you can see of the constellation it is in. Sirius is in Canis Major, Procyon is in Canis Minor, and Betelgeuse is in Orion. 5. Other constellations adjacent to Orion Must also be completed in April Draw and label the constellation Canis Major, Canis Minor, Gemini, and Auriga. Label the stars Sirius (in Canis Major), Procyon (in Canis Minor), Castor and Pollux (in Gemini), and Capella (in Auriga) Also include and label the star Betelgeuse in this drawing. You can include another drawing of the complete constellation of Orion in this drawing as well, with the constellations around it. NOTE: you can draw all these constellations on separate pages. Or, you can do a single drawing with all of them, plus make separate drawings of one, or several, or all of them. 6. Leo Draw and label the constellation Leo (the Lion). Label the brightest star in Leo: Regulus. 7. Virgo Draw and label the constellation Virgo (the virgin). Label the brightest star in Virgo: Spica. 8. Boötes Draw and Label the constellation Boötes (the herdsman, the ox handler, the plowman). Label the brightest star in Boötes: 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. Draw the moon, name its phase, give its altazimuth coordinates, and state which constellation it is in. Also, remember to 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 you will be able to see without a telescope or binoculars. Witnessing more than three of those planets, and documenting your observations well, can add extra points to your night sky project. On your drawings: The Spring Night Sky Spring 2015 Page 4

5 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 the planet General notes on finding planets: The word planet means wanderer. This is because, as seen from Earth, the planets slowly 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. Spring 2015 Planet-Finding Notes Venus To see Venus this spring, look above the western horizon after sunset. Venus will appear in the sky after sunset first, out-shining any star. Jupiter, the largest planet, will be the second easiest planet to see from Earth this spring. Jupiter and Venus both will shine brightly after dark in the west-southwest, with Jupiter higher up and to the left of Venus. Saturn will be rising in the east after dark and will climb higher in the southern sky by midnight. Mars will be visible in April above the western-southwestern horizon as soon as it gets dark. But Mars will only be visible the first couple weeks of April before our line of sight towards the planet is aligned too close to the Sun. After that, you will have to wait until late May or early June, when you might catch Mars rising in the east prior to dawn. Mercury is hard to see because it is the planet closest to the Sun, making it difficult to make out in the glare of the Sun. Use the following table to record the date/time and altazimuth coordinates for observing targets from the list above, and the moon if you observe it. In addition, in the table below, write your measurements of the altazimuth coordinates of each planet you saw and measured. Finally, measure the angular separations listed in the last three rows and write them down in the table. The Spring Night Sky Spring 2015 Page 5

6 Date and Time: Sirius azimuth: altitude: Date and Time: Procyon azimuth: altitude: Date and Time: Arcturus azimuth: altitude: Date and Time: Spica 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: Jupiter azimuth: altitude: Date and Time: Saturn azimuth: altitude: Date and Time: Mercury* azimuth: altitude: Date and Time: Angle between Jupiter and Saturn: Venus: Date and Time: Angle between Spica and Regulus: Spica: Date and Time: Angle between Regulus and Arcturus: Jupiter: *Mercury altazimuth coordinates apply only if you see Mercury, and are not required. The following, however, is required on successful night sky observing projects: Do not draw lines connecting stars in your constellations. Only draw what you actually see. Include some horizon features on any drawings you make that show stars located in the lower half of your sky, to orient your sketch for those who look at it later. Houses and trees, or else hills, are typical horizon features. Put the date and time on each page of your drawings. Record the complete set of weather data and other information (see instructions on page 3) for each night you observe, either on a separate page for each date, or else in a corner or edge of the page if you do one drawing that night, or else on the first drawing for that night if you do several drawings in one night. The Spring Night Sky Spring 2015 Page 6

7 Addendum to Spring Night Sky Project 2015 If you missed your chance in April to observe Orion, the Winter Triangle, and other constellations adjacent to Orion, then you can do this (see below) instead to add some chops, kudos, observing, and points to your Spring Night Sky project. Due to instructor s mailbox in the hallway in Batjer Hall the mailbox with his name on it, or else slipped beneath his office door, room 3008 Eller-Fox, or else handed to him in person if you see him. Due by 2:00 PM on Monday, June 8, A. The constellation Hercules. Find and draw the constellation Hercules. B. The planet Venus and the constellation Gemini. Besides labeling Venus and the general zone of Gemini, label the two brightest stars in Gemini, Pollux and Castor. (Need to do this before it gets very late at night, or Gemini and then Venus will have followed the Sun down below the western horizon and set.) C. The planet Jupiter and the constellation Leo. Besides labeling Jupiter and the general zone of Leo, label Regulus, the brightest star in Leo. (Need to do this before it gets very late at night, or Jupiter and then Leo will have followed the Sun down below the western horizon and set.) D. The constellation Virgo. Find and draw the constellation Virgo. E. The planet Saturn and the constellation Scorpius. Find and draw the constellation Scorpius and the planet Saturn. This is best done after 11:00 PM or after midnight, when they are higher in the southern sky. Doing these five separate night sky drawings will replace Orion, the Winter Triangle, and other constellations around Orion, if you missed doing those in April. Due by 2:00 PM Monday, June 8. ASTR& 101 Spring Night Sky 2015 page 7