Set Starry night to display the sky on January 1st of this year at 10 PM from Ann Arbor. Stop the time flow.
Find Ursa Major (the Big Dipper). Zoom in on the middle 'star' in the handle of the dipper until you can see it is really a double star, Alcor and Mizar. Hold the pointer over one star and then the other; this brings up the information box. (Reminder: you can right click/ctrl +click and center, then use the + button in the zoom area of the toolbar to zoom in)
Click and drag from one star to the other.
Zoom back out until you can see whole constellations again. Face south and find Orion. Turn on the Celestial Guides grid and equator to show the lines of Right Ascension and Declination. Record the RA and Dec for Rigel and Betelgeuse, two prominent stars in Orion. (Hint: The information the pointer gives you about each star will tell you the coordinates of the star, too. Be sure to include the direction of the declination, i.e. +/North or -/South).
Note that from these declinations the Celestial Equator (at 0º declination) must pass through Orion. What is the name of the star in Orion's belt that is closest to the Celestial Equator? What are its RA and Dec?
You know Polaris, in Ursa Minor, is the star presently closest to the north celestial pole. Find Polaris. Record its altitude along with the latitude and longitude of the viewing location for Ann Arbor, Oslo Norway, and Honolulu Hawaii in the table below. (Hint: The latitude and longitude are in the box that allows you to change your Viewing Location. Reminder: to change your location, click the down arrow in the “Viewing Location” area of the toolbar).
|Location||City Longitude||City Latitude||Altitude of Polaris|
Now reset your location to Ann Arbor. Turn off the RA and dec lines, but leave the celestial equator on. Turn on the ecliptic (Reminder: that’s “equator” under “Ecliptic Guides” in the options tab.) Turn on the constellation boundaries. Uncheck Daylight under Local View. Find and center on the Sun.
Record the distance between the Earth and the Sun on December 21 in the table below (Hint: the distance between the observer and the Sun is the same as the distance between the planet the observer is on and the Sun!). Also record the Right Ascension and Declination of the Sun. Repeat the above measurements for the summer solstice (June 21) and record those values in the table.
|Date||Earth-Sun Distance (AU)||Right Ascension||Declination|
You now want to look at the motion of the planets in the sky relative to the Sun. Set the time to noon, today. Set the time flow rate to one day. Make sure daylight is still off. Under the find tab, clear anything in the search bar so you get the list of solar system objects. Click the arrow next to the Sun and choose “Centre” to center the display on the Sun; Click the check box next to Mercury to label it. Set the sky in motion and observe Mercury's path. After watching how it moves, return to today at noon, click the checkboxes next to the other planets so you can track them, and answer the following questions. You may want to step time forward to make all the observations.
Set the sky running and watch as Mercury and the other planets exhibit retrograde motion. Reset the date and set the time to noon today. Look towards the south. Using a time increment of 1 day, set the sky in motion.
Return to noon today, and face south. Change the time increment to "Sidereal d.'' which is the sidereal day: 23h 56m. Set Starry Night running again.
The zodiac constellations are the constellation the Sun passes though
For the next few questions, set Starry Night to your birthplace location, as well as birthdate and approximate time (make it noon if you have no idea what the time is.) You will need the constellation boundaries on, and having the ecliptic on may be helpful.
Location: _____________________Date and Time: ______________________
Set Starry Night to the present location (Ann Arbor) and date, and set the time to 9:00 PM.
Last modified: 5/18/07 by SAM based on TheSky lab
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