INDEPENDENT PROJECT: The Autumn 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 Autumn 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 15-30 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 Autumn Night Sky Autumn 2014 Page 1
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 OBSERVATIONS 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 Autumn Night Sky Autumn 2014 Page 2
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. Stars and Constellations of the Summer Triangle asterism The Summer Triangle is an asterism, a named group of stars that is not one of the 88 official constellations. The Summer Triangle is composed of three bright stars that form a triangle overhead. The stars are Vega, Deneb, and Altair. Vega, highest and brightest of the three stars, is in the constellation Lyra (the Lyre, a stringed musical instrument). Deneb, east of Vega, is in the constellation Cygnus (the Swan). Altair, south of the other two stars, is in the constellation Aquila (the Eagle). Draw and label the constellations Lyra, Cygnus, and Aquila. Label the brightest star in each constellation (Vega, Deneb, and Altair, respectively). Include the other stars you can see in each constellation in your drawing(s) of the Summer Triangle. Do not label the lesser stars in each constellation. 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. Boötes Note that you will need to observe Boötes in September or October. It will be out of sight after that. Draw and label Boötes (the Plowman or Ox-driver). Label the bright star Arcturus. 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. The Autumn Night Sky Autumn 2014 Page 3
4. Hercules Draw the constellation Hercules (mythical hero and son of Zeus; one of his accomplishments was completing the 12 Tasks of Hercules). Label the constellation Hercules. 5. Scorpius Draw and label the constellation Scorpius (the Scorpion). Label the brightest star in Scorpius, the reddish star Antares. 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. 6. Pegasus and Andromeda Draw the two constellations Pegasus (the Flying Horse, or Winged Stallion) and Andromeda (the Ravaged Beauty, daughter of Cepheus and Cassiopeia). These two constellations spread fairly widely over a large area of sky, and seem to connect together at one corner of the Great Square of Pegasus. Label the constellations Pegasus and Andromeda. Mark and label the Great Square of Pegasus. Draw and circle and label with M31 the location where the galaxy M31, the Andromeda Galaxy, is in Andromeda. 7. One or more of the pre-dawn, winter constellations. These winter constellations come up in the autumn sky between 2:00-4:00 AM and dawn. Choose at least one. For each one, draw it, label it, and label its brightest star (or brightest two stars). Choose one (or more) of them at least one is required. The winter constellations are near enough each other that you can include more than one in a single drawing. The winter constellations are Gemini (brightest stars in Gemini are Castor and Pollux), Canis Major (brightest star is Sirius), Canis Minor (brightest star is Procyon), Auriga (brightest star is Cappella), and Taurus (brightest star is Aldebaran; if you do Taurus, also draw and label the Pleiades cluster in it). 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. The Autumn Night Sky Autumn 2014 Page 4
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 planet. Label the constellation each planet is in. Give the altazimuth coordinates for each planet General Notes on Finding Planets The word planet means wanderer. This is because, as seen from Earth, the planets slowly move, or 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. 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. Autumn 2014 Planet-Finding Notes Mars: Mars will be in the constellation Libra at the beginning of autumn, and then it will slide eastward into Ophiucus and will pass above the bright reddish star Antares in the constellation Scorpius. In star myth, Antares is another warrior and the rival of Mars. Saturn: The ringed planet will be visible low in the western sky the first several weeks of fall, following the sun down. After a few weeks, Saturn will be too low in the sky, and too near the sun, to see. At the end of the quarter, Saturn will become a planet seen only in the early morning, rising ahead of the sun. The Autumn Night Sky Autumn 2014 Page 5
Venus: The planet Venus plays the role of morning star" during the early weeks of fall quarter. You can see it above where the sun is coming up in the east, after about 5:00 in the morning Jupiter: Jupiter will be another morning star, rising in the east around 4 o clock early in the quarter, rising earlier in the morning as the months go by. Mercury: Mercury is the planet closest to the sun. The glare of light from the nearby sun makes it difficult to spot Mercury. However, during the first two weeks of fall quarter, Mercury may be visible above the western horizon just after sunset. The planet will be in the glow of twilight above the horizon, near the path the sun followed down. The Autumn Night Sky Autumn 2014 Page 6
11. Azimuths, altitudes, and angles see handouts on measuring angles and measuring altazimuth coordinates distributed at the beginning of the quarter. Date and Time: Polaris azimuth: altitude: Date and Time: Arcturus azimuth: altitude: Date and Time: Vega azimuth: altitude: Date and Time: Deneb azimuth: altitude: Date and Time: Altair azimuth: altitude: Date and Time: Aldebaran azimuth: altitude: Date and Time: The moon azimuth: altitude: Date and Time: The moon azimuth: altitude: Date and Time: Write in planet of your choice: azimuth: altitude: Date and Time: Write in planet of your choice: azimuth: altitude: Date and Time: Angle from Jupiter to Betelgeuse angle: Date and Time: Angle from Vega to Polaris angle: Date and Time: Angle from Altair to Mars 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 Autumn Night Sky Autumn 2014 Page 7