Download Name

Name _______________________________________________ Date ________________
Partner _________________________________________________
Astronomy Exercise #6: Voyager Planetarium Software
by M.L. West
Objective: to become familiar with the constellations and the planets using the Voyager interactive
desktop planetarium software.
Procedure: On the computer go to Start, All Programs, Carina Software, Voyager 4.5
I. Introduction to coordinates and constellations
A. Pull down Chart, Coordinates, Star Atlas-Equatorial.
Try dragging the lower scroll bar leftwards. What happens? (RA __________, Dec ___________).
As you drag the right side scroll bar upwards, RA __________, Dec __________.
B. Try Center, Set Chart Center, RA = 5 hours, 0 minutes, Dec = 0 degrees, 0 minutes.
Do you recognize any constellation stick figures? One of the constellations visible on the screen is
_______________.
Use the top menu bar to get Display, Constellation Figures.
Also select Display, Constellations, Names
Mouse crosshair click on any star in that constellation. Its Info box includes the star's
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
Try clicking on “Show” in the Info box. What happens? ________________________________
Close the Info box.
C. Use the menu to Display, Constellations, Zodiacal Constellations. Click on the grid button
to see the grid lines come and go. Drag the scroll bars to locate the two places where the zodiac
crosses the celestial equator (Dec = 0°, middle horizontal grid line).
This is at constellations _____________ (_________ Equinox), and _________________
(________ Equinox). How did you figure out which constellation was the autumnal equinox?
_________________________________________________________________
Remove the zodiacal constellations.
II. Where are the deep sky objects?
A. Try Center, Orion. Zoom until your field of view is roughly 26° x 19°.
2
Display, Deep Sky Objects. Use the selection check boxes to show only the bright nebulae, open
clusters, globular clusters, and spiral galaxies. Count the number of each of these in this area.
bright nebulae ________,
open clusters _________,
globular clusters __________,
spiral galaxies ________
B. Now slowly search the sky for a different region which is richer in spiral galaxies than the
Orion region is. The region you chose is in the constellation __________________________,
at RA = ____________, Dec = ____________.
In this area count the numbers again:
bright nebulae ________,
open clusters ________,
globular clusters __________,
spiral galaxies ________
How do the numbers of spiral galaxies and bright nebulae seem to be correlated?
________________________ (Hint: make a quick prediction plot with only two data points.)
III. Planets and their apparent motions
Turn off all the deep sky objects (Display, Deep Sky Objects, unclick Show Deep Sky Objects).
A. Saturn's Motion
Display, Planets and Moons, Moons, click off Major Moons.
Use Control, Set Time and Date, and type in today’s date and time.
Use Center, Saturn. Draw its symbol:
Saturn is now in the constellation _____________________. (Use Display, Constellation Boundaries)
Turn off the constellation boundaries.
Zoom to a field of view of about 100 degrees wide.
On the Time Panel look to check that the time step is 1 day.
Display, Saturn. Click on Paths, In the Time panel, click Start. Sketch what happens.
This behavior is called ______________________________________________.
How often does Saturn do this? _______________________ Describe your method to determine this:
B. Mercury's Motion
Center on Mercury and turn on its Paths. Sketch what you predict will happen:
3
Locate Mercury and try it. Was it any different from your prediction? ______________________
How often does Mercury do this? __________________ Is it different from Saturn?
Display the zodiacal constellations. The reason for this loopy behavior is more apparent if you show
the sun as well as Mercury. Center on planets, the sun. (I know, I know; it is not really a planet.)
Click on the sun symbol and Lock your view on the sun.
Click the Start time again. Now what happens? (Stop after a good loop.)
What is the real reason for Mercury's loops and who proposed it?
C. How would Mercury’s path look from a different planet? Try Location, Solar System,
Jupiter. Now try tracking the sun and Mercury again. Describe the differences from what you had
observed from Earth.
Copernicus would have loved this. Return to Earth.
IV. The Solar System as seen from above the north pole
A. How many planets are there? _____.
Predict which way they move as seen from far above the Earth’s north pole ___________________.
Use Location, Solar System, Heliocentric longitude about 180 degrees, Heliocentric latitude about 90
degrees, distance from sun about 30 au. Set the time step to one year.
Make the time go forward and notice which way the planets move (______________________).
By the way, what is 1 au? ______________________________
Return to Earth, please. Unlock the sun.
B. What did the solar system look like on your actual birthday (________________)?
Use Chart, Set Date and Time.
Where were you born? ____________________
Use Chart, Set Location.
As seen from the earth, which constellation was the sun in front of? _____________________.
Adjust the scroll bars to get as many planets as possible in the field of view with the sun. Put on the
constellation outlines and their names. Describe, sketch or print.
V. Discussion Questions
A. Define open cluster, globular cluster, spiral galaxy, bright nebula, inferior planet, superior
planet.
B. Which are further away, spiral galaxies or bright nebulae? Why do they show the
correlation you found in II B?
C. Suggest how you could use this software to verify easily the curve of "hours of daylight vs.
month" deduced laboriously in the previous lab exercise on the celestial sphere.