Marymount
Astronomy 101 Lab
Introduction to Stellarium
This lab will require the use of the Stellarium planetarium software. If you have not already downloaded it, go to http://www.stellarium.org/ and click on your operating system on the upper right of the screen. The download should then begin.
I. SUNRISE, SUNSET
The sun rises, crosses the sky, and sets in different places depending on the time of year and your location on Earth. This exercise demonstrates the differences in the sun’s path.
1. From the tool bar on the left, select your location (or you can use F6). Arlington, VA or Washington DC will be close enough.
2. Now turn on the ecliptic line and cardinal points (Sky and Viewing Options, on the left hand menu).
3. From the Date/Time window, move the time forward and backward until you get the right times for sunrise and sunset. Remember the sun (and all other celestial objects) rises approximately east and sets approximately west so you will have to drag your screen around to see both east and west cardinal points.
Time of sunrise_________________________ Time of sunset____________________________
Direction of sunrise______________________ Direction of sunset________________________
4. Now, forward the date to December 21st and note time and direction of sunrise/set.
Time of sunrise_________________________ Time of sunset____________________________
Direction of sunrise______________________ Direction of sunset________________________
5. Change the date again now to the fall equinox, September 22rd.
6. Set the Latitude now to 90 degrees North (the North Pole).
Time of sunrise_________________________ Time of sunset____________________________
Direction of sunrise______________________ Direction of sunset________________________
II. Constellations
1. Ancient cultures made pictures in the sky by connecting the dots between stars. These resulting star patterns are called constellations. There are 88 constellations total in the sky from western culture. Other constellations were formed from other cultures (Chinese, Navajo, etc.).
2. On the bottom menu, turn on constellation lines and constellation names. Now find the Big Dipper. It is not a true constellation although many cultures have made it into pictures. The Big Dipper is a part of a larger grouping of stars (constellations) called Ursa Major which means the “Big Bear”. The Big Dipper, itself is an “asterism”, not a true constellation. Find the two end stars in the cup and draw a line to Polaris, the north star. If you curve the line a bit and keep going about the same distance, you will come to a “W” or “M” shaped constellation called Cassiopeia. Now go back to the Big Dipper. Follow the curve of the handle from the cup to the end and keep going until you hit a bright, “1st magnitude” star called Arcturus….think “Arc to Arcturus”. This is the brightest star in the constellation Bootes and so is also called Alpha Bootes. The second brightest star in Bootes is Beta Bootes, and so on.
3. Draw the Big Dipper. For each star in the Big Dipper, write its name, spectral type (we’ll discuss what this is), and distance. Now do the same for the Little Dipper. Polaris is the last tail star in the handle of the Little Dipper so it should be easy to find. Do the same again for Cassiopeia.
4. Now find Orion, the hunter. Is it up? What time does it rise (approximately). Now zoom in on the stars that make up Orion’s sword (just below the three stars in his belt). The middle star is actually the remains of a massive star that exploded (super nova) and left a beautiful nebula called the Great Nebula of Orion. Draw and name the stars in Orion.
III. Right Ascension and Declination
1. The sky above you is of course 3-dimensional but it is a bit challenging to perceive depth or distance. So, we can think of the sky as a celestial sphere with us at the center. This sphere has a 2-dimensional surface as all spheres do. A road map also has a 2-D surface. To locate a certain point on a map of the US or the world, you would use latitude (angular distance above and below the equator) and longitude (angular distance around the globe, from east to west). On a sky map, we also use two coordinates to locate an object in the sky. These are Right Ascension (RA) – similar to longitude, and Declination (Dec) – similar to latitude. Declination is measured as degrees above or below the “Celestial Equator”. So, an object on the celestial equator, has a Dec of 0 degrees. An object at the celestial north pole (e.g. Polaris….almost) has a Dec of +90 degrees. Right Ascension is measured as hours, minutes, and seconds around the celestial equator from the vernal equinox up to 23 hours, 59 minutes, 59.999… seconds. Find and list the RA and DEC coordinate pairs for:
– Polaris
– Antares
– Vega
– Rigel
– Deneb
– Alioth
IV.
1. Go to the Sky and Viewing Options Window and click on Star Lore. Click on any of the countries/cultures and notice the patterns and names in the sky that were / are important to them. Name two constellations that you found.
2. Count the number of days between the spring equinox and the fall equinox. Now count the number of days between the fall equinox and the spring equinox. Write the two answers here:
Number of days between Spring and Fall Equinox:
Number of days between Fall and Spring Equinox:
3. Are they the same? Discuss what you think is going on.
What Students Are Saying About Us
.......... Customer ID: 12*** | Rating: ⭐⭐⭐⭐⭐"Honestly, I was afraid to send my paper to you, but you proved you are a trustworthy service. My essay was done in less than a day, and I received a brilliant piece. I didn’t even believe it was my essay at first 🙂 Great job, thank you!"
.......... Customer ID: 11***| Rating: ⭐⭐⭐⭐⭐
"This company is the best there is. They saved me so many times, I cannot even keep count. Now I recommend it to all my friends, and none of them have complained about it. The writers here are excellent."
"Order a custom Paper on Similar Assignment at essayfount.com! No Plagiarism! Enjoy 20% Discount!"
