101 Astronomy Online Summer 2007 - Alternate Observing Project
There's nothing quite like being able to look through a telescope at a distant object in the night sky. As you would imagine, the project you are about to do is not really a suitable replacement for that experience, but we'll have to make the best of it. For this project, you'll be doing some observing in Starry Night, as you would have done if you were out at Atwood. Start by setting Starry Night to the following conditions: Date: 7/6/2007 Time: 9:30 PM Daylight Time Time Flow: Frozen (hit the stop button) Viewing Location: Champaign (or Urbana, if you don't have a Champaign entry)
Now get yourself oriented. Since the sky isn't quite dark yet on the program, go into the View window and select "Hide Daylight". Without any labels on, see if you can find the Big Dipper and Polaris. If you can't, it's okay to turn on labels to help you out. If you want to turn on the drawing for the Big Dipper, you'll need to go into the "View" menu and select "Constellations -> Asterisms" and "Constellations -> Labels". 1) When facing Polaris, is the Big Dipper to the right or left of Polaris? To the left 2) Find the star Dubhe in the bowl of the Big Dipper. Double click on it to open the info window. What is Dubhe's right ascension and declination? 11h 4.21m 61d 42.615 3) Scroll around the sky to find the Milky Way. Where does the Milky Way meet the horizon? Express your answer in terms of the cardinal points. Remember that it will cross the horizon at two points. It crosses at south and north Under the "View" menu, select "Constellations -> Boundaries", "Constellations -> Labels" (if you haven't already turned them on), and "Constellations -> Astronomical". The constellation stick figures should now appear along with the constellation names and boundary lines. If you don't know the constellations of the zodiac, you will want to refer to "Table 1-1" on page 21 of your textbook. 4) Which constellation of the zodiac is now setting in the west? Cancer 5) Which constellation of the zodiac is now rising in the east? Sagittarius It's time to let the real observing begin. There is a wonderful catalog of deep sky objects that you can see with a pair of binoculars or a small telescope. This catalog is called the Messier catalog and is included within Starry Night. Under the Labels menu, turn on "Messier Objects". You will now be observing several of these Messier objects, several of which you would have seen out at Atwood.
Begin by locating M8 (Lagoon Nebula), an emission nebula cluster. Note: If you are having trouble finding any of the objects listed below, you can use the "Find" tab. If you used the Find menu, double-click on the entry for M8. If you found in the night sky, rightclick on M8 and select "Centre". Change your field of view so that it is roughly "3 x 2 ". This is similar to what you would see through a small telescope. 6) Write a description of an emission nebula (you will have to look this up in the textbook). Record the constellation in which the object is found? Write a description of what you see in the field of view. A nebula is a glowing, gaseous cloud of interstellar dust, which gains florescence from a nearby star. When I viewed the Lagoon Nebula I saw a large red field with white bits scattered in it as well, it was located in the Sagittarius constellation. Repeat the above procedure for the following objects. For each object: Answer the question given Write a description of what you see in the specified field of view Record the constellation where the object is found Record the common name of the object 7) M20 - roughly 3 x 2; what is a reflection nebula? (note: this is in the same field of view as M8) It looks the same as M8 but instead of a red gaseous ball it is a blue green hue, it is located in Sagittarius and is called the Trifid Nebula. 8) M13 - roughly 1 x 1; what is a globular cluster? A globular cluster is a group of gravitationally bound stars the Hercules Cluster looks just as such a sphere packed full of stars and is located in Hercules. 9) M81 - 1 x 1; what is a spiral galaxy, what other galaxy is in the same field of view? Bodes galaxy close to the nearby Cigar Galaxy is a spiral galaxy which is a flatted, rotating galaxy with spiral arms winding out from the galaxies nuclear bulge, M81 is located in Ursa Major, when I viewed it, Bodes galaxy looks like a giant disk with swirls of beautiful color in it. 10) M 7 - 1 x 1; what is an open cluster? Ptolemys cluster is a loosely held group of stars bordering the disk of the galaxy located in Scorpius, it looks like a group of stars held fairly close together, very pretty. M51 11) - 1 x 1; what type of galaxy is this & what else do you notice about the object? Located in Canes Venatici is the Whirlpool Galaxy which is very interesting because it looks like a normal galaxy except it has a bridge which connects it to a neighboring galaxy, many top astronomers believe at the center of Whirlpool is a giant black hole. 12) The M in the above objects stands for Messier. Who was Charles Messier, why did he compile a catalog of sky objects, and what objects are included? (you will need to look this up) Charles Messier compiled his list of deep sky objects to help future astronomers and meteor
hunters to be able to determine the difference between transient objects in the sky and permanent ones. Find the constellation of Lyra. The brightest star in Lyra is Vega. Center Vega and zoom in to a field of view about 3 x 3 and look for two stars close together below and left of Vega. One of the stars is Epsilon1a Lyrae. Center this star, and use the magnifying glass to zoom in on them until the field of view is close to 1' x 1'. (note that this is arcminutes and not degrees) 13) What do you notice about Epsilon1a Lyrae at a field of view of 1' that you didn't notice at a 1 field of view? There are 2 of them which is neat, 4 all together in the collection of Epsilon Lyrae. 14) Open up the info window for each star. Record the temperatures of the stars. What is the luminosity of Epsilon1a Lyrae? 1a- 8010 Kelvin with a luminosity of 31 suns, and 1b- 7265 Kelvin Zoom all of the way back out. Search around the sky to see how many planets you can find. You can turn on their labels under the Labels menu, if that helps. 15) How many planets are visible at this time? List them here. (Do not include Earth.) Venus, Saturn, and Jupiter. Center and lock onto Venus. Select the field of view to roughly 1' x 1' (at this magnification you can see some details of the planet and the phase) 16) Describe the planet as you see it on the screen, including the phase. Define Terrestrial planet. It is in its waxing crescent phase and is about 35% illuminated on its right. Now, zoom back out to about 10 x 10 field of view. Saturn should appear to the right of Venus. Center Saturn and zoom back in to a field of view about 1' x 1'. (You can see features of the planet and several moons at this magnification.) 17) Describe the planet Saturn as you see it on the screen. Define Jovian planet. It is tilted in such a manner that its rings are almost vertical, Saturn being a jovian planet which is an extremely large body in the solar system compared to terrestrial planets and are the farthest from the sun. 18) How many of Saturn's moons are visible? What are their names? Describe their positions relative to Saturn. 5, three to the southeast, one to the north, and one to the east of Saturn, their names are: Titan, Rhea, Dione, Tethys, and Enceladus. 19) What constellation are Venus and Saturn in on this date? Leo
Zoom back out as far as you can, and change your view direction to the southeast. If you have the planet labels on, you will see Pluto and one other planet. Pluto is so small (\not even classified as a true planet anymore), so you can disregard it for our observation. 20) What planet is in the field of view now? Jupiter Zoom in until your field of view is approximately 6 x 6 (you can see details on the planet and the four largest moons labeled at this magnification). 20) Describe the layout of the four largest moons and their orientation relative to the planet. Disregard the moon directly in front of the planet. They are almost in a straight line going from the southwest to the northeast in a diagonal direction. 21) Turn off the planets-moon labels, zoom in to a 1' x 1' field of view and describe the appearance of the planet. A lot of rust color and a lot of swirls, there is also one very large swirl that sticks out. The real sky observations usually last about an hour. Set your view to the south now, with the horizon at the bottom of the screen. Set the time step to 1 hour and watch the screen as you move forward by one one-hour time step. Watch Jupiter and gauge its change in position. 22) Describe how much the sky has moved during the one hour observing session. The sky moved about 5-10 degrees total with Jupiter going farther north. The observation dates were chosen so that we would not have to worry about having the Moon present during the observations. Open the "Find" tab on the left and double-click on the Moon. Before you click on the any of the buttons, be sure to find the rise time of the Moon in the window that pops up. 23) What time will the Moon rise? 12:00 AM Click on the button marked "Best Time". Open up the "Info" tab. 24) What is the disk illumination and phase of the Moon? 53% third quarter