Stellarium Planetarium Project, science homework help
Stellarium Planetarium Project
Software
Installation
Stellarium is free
planetarium software that runs on many different operating systems. You should download the appropriate version
for your computer. Go to the following
website: http://www.stellarium.org/ and
read the basic information about the program and what is included in the latest
version. The User's Guide provides a
good walk-through for the preliminaries like controls, features and 'setting
home location'. You will need to consult
the User’s Guide to figure out how to do many of the tasks given below. For example, the time flow icons and shortcut
keys are described there. You’ll need
some practice to learn how to use them.
I’ve tried to put quite a few details into the instructions (short-cut
keys, etc.), but you will still encounter things that you’ll need to figure out
on your own, so be prepared to consult the User’s Guide for some things.
After the software is installed and tested, we need to set
our geographic location. The top icon on
the left toolbar (or shortcut key F6) will take you to the location
window. Although there are hundreds of
cities around the world listed in the window, you may not find your own city
listed there. So we must input a city
manually and save it to the list.
Type “your city” or UMUC Adelphi into the Name/City box and your geographic
coordinates and elevation into the latitude (N 38° 59’ 10.032”) and longitude (W 76° 57’ 17.208”) and altitude (46
m) boxes. Check the “Use as default” box
and click on the “Add to List” button.
This will add your city or Adelphi to your cities list.
This project consists of three sets of
“Activities”. Activity I is
designed for this “home” location. (All instructions refer to the Stellarium
virtual sky unless otherwise stated.)
Activity I: [14 Points]
Note that Stellarium
will come up in the full-screen mode. If
you wish to move back and forth from this document to Stellarium, press the F11
key to display the window in partial –screen mode so that you can jump back and
forth by using the icons on your bottom toolbar.
Step 1. View the sky at the “home” location for the cases: daylight on, daylight off, light pollution on
and off; comment briefly on the differences that you see.
Daylight is toggled on and off with the Sun icon on bottom
toolbar (“a” key shortcut). Light
pollution is controlled in the Sky and Viewing Options window (icon or F4
key). It goes from 1 (no light
pollution) to 9 (severe light pollution, such as downtown Baltimore
or New York City). The default starting value is 3. When you turn the ground off, you’ll see a
band of fog across the screen. This can
be turned off under Landscape in the same F4 window (“f” key shortcut) [2]
Step 2. Play around with the view by dragging the field of view up and down to
look at higher and lower angles; drag the sky left and right to view directions
other than the starting south. (The
arrow keys also change the viewing direction.)
Zoom in and out with the mouse wheel or with the page up and down
keys. Comment on the changes. [2]
Step 3. Try different
time flows and different times of the day and comment briefly on the
changes. The right and left arrow
buttons on the bottom menu are used to flow the time. Additional clicks speed up the time. The down arrow in the menu steps the flow
backward and repeats. [2]
Step 4. Try to locate
the following and note on your report what you had to do to find them. Hint:
Mercury and Venus are always near the Sun, so if it is daylight, turn
that off with the atmosphere icon in the bottom toolbar or the “a” key. Make an entry for each object, explaining
briefly the steps that you took to find the object. To search for an object, click the Search
Window button on the left menu or press F3.
If an object is below the horizon, remove the ground (bottom menu or
lower case “g”) or flow the time backward or forward until the object is
visible. Make an
individual entry for each of the objects below.
Planets Mercury, Venus, and Jupiter, the star Sirius (α CMa
or Canis Majoris), one red giant star (a K or M star of luminosity class III),
and one main sequence star (luminosity class V). To find the red giant and main-sequence
star, you will need to pick out bright stars and click on them to see their
information boxes. (Do not use the Sun or Sirius as your main sequence
star.) An information box in the
upper left of the window will give the star’s name (for bright stars)
constellation designation (you can also turn on constellation boundaries and
labels by clicking the appropriate icons in the bottom toolbar) and other
information. Spectral types and
luminosity classes are given near the bottom of the box. Luminosity class goes from VI (subdwarfs
[rare]) to supergiants (I). The
following classes are present:
VI: subdwarfs; V
(dwarfs); IV (subgiants); III (giants); II (bright giants); I (supergiants).
Identify the stars by their proper names and their Bayer (Greek letter) and/or Flamsteed (Arabic number) designations. Do not identify them
exclusively by HIP number, although you can include that if you
wish. We will learn more about what
main-sequence stars and red giants are in Module 5). [6]
All bright stars have designations
that end in constellation name; e.g., Col. However, there has to be a Greek letter or
some other character ahead of Col;
or, the object must have a formal name like Sirius, Vega, etc. In your case, the HIP number tells me that
the star is λ Columbae with a spectral type of B5 V.
Step 5. View the constellations and locate a bright star in
your favorite constellation. Since many of you are doing this as a family
project, I am leaving you some freedom and choices here. Be sure to identify the constellation and the
star chosen. Choose a bright star that
has a proper name and/or a Bayer and/or Flamsteed designation. A Bayer designation is a Greek letter name
such as α Orionis. A Flamsteed
designation is an Arabic number name such as 58 Orionis. When we combine these names, we get a
designation like 58 (α) Orionis. This
star (like many other bright stars) has the proper name Betelgeuse. Any star designation must have a
constellation designation (genitive form or 3-letter abbreviation) appended to
it to be valid. Note that stars with Bayer designations
in Stellarium do not have Flamsteed identifiers present. [2]
Activity II.
Planetarium Exercises [70]
At the end of each
exercise, we will quit the program so that when we execute it for the next
activity, it will start with the default time and values. You should have a Stellarium icon on your desktop to make execution
easier. You can use the Windows Explorer
to create a desktop icon. Go to the
directory where Stellarium is located and right click on the exec file. Select create shortcut and place it on your
desktop. Right click the icon and rename
it to Stellarium (with a version ID if you like).
Planetarium
Activity #1: Motions of the Stars
Read
through all instructions before starting, so you'll know what to look for.
Set
the time to 1600 hours (4 p.m. [click the clock icon or press F5]). Turn daylight off using the Sun icon or the
“a” key. Face West (by using the “hand
tool”; that is, clicking on the sky near the horizon and dragging the field of
view around so you're facing West).
Change the time flow rate with the double right arrow icon.
Q1. What happens?
Describe how the celestial objects appear to move (for instance, in what
direction, from where to where?). Think
about how the real sky moves as Earth rotates from W to E.
Now
face North (again by dragging the field of view around).
Q2. With the time fast-forwarding, how are the
stars moving? What is the type of
motion and in which direction (clockwise
or counterclockwise)?
Q3. Do you see the Big Dipper (in the
constellation of Ursa Major -- the Great Bear)?
(If
not, you can turn on the constellation names and outlines by using the icons on
the left in the bottom toolbar). You may
need to zoom in or out using the mouse
wheel or Page Up or Page Down keys. Note
the pole pointer stars at the end of the Dipper’s bowl and follow them to the
North Star (Polaris).
Click
the quit icon at the right of the bottom toolbar or quit with ^Q.
Planetarium
Activity #2: Zodiacal Constellations
Read
through all instructions before starting, so you'll know what to look for.
Activate
the Stellarium program again. If it’s
daylight, turn “atmosphere” off with the toolbar icon or with “a”.
Turn
on constellation “Boundaries” and “Labels”.
The latter is controlled with the icon on the left of the bottom toolbar,
while the former requires that you activate the Sky and Viewing Options window
in the left toolbar or with F4, then choose Markings, then click the Show
Boundaries box under constellations. The
corresponding shortcut keys are “v” and “b”.
In
the Markings menu (see above), also turn the Ecliptic line on by checking the
box under Celestial Sphere.
Face
East (by dragging the sky around until the “E” compass point is in front of
you. The ecliptic line (orange) is labeled -- the apparent path
that the Sun follows through the constellations in the course of the year (also
the plane of the Solar System)..
Q1. Before you put the sky into motion, answer
this: Through how many constellations do
you think the ecliptic passes?
Now
set the sky into motion with the time flow double arrow icon in the bottom
toolbar. The stars are now rising in the
East and you are moving along the ecliptic.
Adjust the speed to one that is comfortable for you.
Q2. List the constellations that the ecliptic
goes through as you see them rise. (To see all the constellations that the
ecliptic passes through, you have to keep watching the ecliptic for an entire
day. While you are doing this, you may need to drag the sky a little one way or
another to keep the ecliptic in view.)
At some point, the Sun will come into view and should be smack on the
ecliptic line.
Q3. How many constellations does the ecliptic
actually go through?
Q4. Did you get the answer you expected? Why or why not?
Stop the time and set the date
to your birthday (by clicking on the date/time icon or F5) and using the
up/down arrows to set the date. You may
keep the year the same, as that won’t affect constellation positioning. If it's not already daytime, change the time
so that it is. Locate the Sun by flowing the time until the Sun is up, but keep
daylight off. Alternatively, you can use
the find menu in the left toolbar (or F3) to find and center the Sun in the
sky.
Q5. What constellation is the Sun in? (If the constellation name is below the
horizon, you can fast-forward the time until it becomes visible.)
Q6. Is it what you expected? Why or why not?
Click
the quit icon at the right of the bottom toolbar or quit with ^Q.
Planetarium
Activity #3: Seasonal Sky Changes
Read
through all instructions before starting, so you'll know what to look for. Under “View”, click on “Constellations”
and then “Labels”. Set the time to 2200 hours (10 p.m.).
Q1. Different constellations are visible at
different times of the year. By changing
the date, determine when (Spring, Summer, Fall, Winter) the following
constellations are most easily visible (that is, highest in the sky). You may have to drag the sky around a bit to
find some of them. Be careful to always observe at 2200 hours local time.
Orion
Scorpius
Ursa
Major (the Big Dipper)
Cetus
Virgo
Pegasus
Click
the quit icon at the right of the bottom toolbar or quit with ^Q.
Planetarium
Activity #4: Special Places on Earth
Read
through all instructions before starting, so you'll know what to look for. Face East (by dragging the sky around until
the “E” is in front of you). Set your
location somewhere on the equator by clicking the location icon on the side
toolbar or F6 and changing the latitude to 0 [zero]). Set the time flow to fast forward by clicking
the double-arrow icon two or three times.
Q1. How do the Sun and stars appear to move?
Now
set your location to be near the North Pole by changing the latitude to 90
degrees. (Ignore the grass and trees displayed by the program (or press “g” to
remove the ground); the designers probably didn't have images of ice and
snow. Notice as you drag the sky around
near the horizon that all cardinal directions are S. When you're at the North Pole, any direction
you face is south!)
Q2. Fast-forward.
How do the Sun and stars move now?
Drag the sky upward while it is moving until you reach the North Star
and notice how the sky is moving with respect to Polaris.
Q3. Describe what the Sun is doing. Is it going to rise or set any time
soon? Explain.
Click
the quit icon at the right of the bottom toolbar or quit with ^Q.
Planetarium
Activity #5: The Sun's Maximum Altitude
The
Sun is highest in the sky on the date of the Summer Solstice (June 20 or 21),
around 1300 hours (1 p.m.). (It would be
around 12 noon, but by June, most of the United States has moved clocks
ahead one hour for Daylight Savings Time.)
Is the Sun directly overhead at that time? Let's find out.
Read
through all instructions before starting, so you'll know what to look for.
Turn
on the altitude and azimuth coordinate grid by using the Azimuthal grid icon on
the bottom toolbar (or the “z” key).
Set
the date/time to June 21 (the Summer Solstice) at 1300 hours (1 p.m.). Be sure that you are located at your home longitude and latitude. If you want to check to see where you are
located, use the ACME Mapper website (http://mapper.acme.com). Enter our coordinates (N DD.ddddd, W
DD.ddddd) in the box and click
Find. You can then zoom in on your
location to see exactly where the
coordinates locate you.
Q1. Where do you expect the Sun to be?
Drag
the sky so you're looking up toward the zenith. You will recognize the zenith
because the grid lines meet there. You
should also be able to see the Sun and it should be close to your meridian
Q2. Is the Sun at the zenith? If not, about how many degrees in latitude
(or altitude or declination) from the zenith is it? Do not read the azimuth scale, as that
distance is not relevant to this discussion.
What we want to know here is how far the Sun is from your zenith in the
latitude coordinate.
Q3. Is this what you expected? Discuss.
Can you derive an equation for the relationship between your geographic
latitude and the distance of the Sun from your zenith at the Summer solstice
time?
Click
the quit icon at the right of the bottom toolbar or quit with ^Q.
Planetarium
Activity #6: Light Pollution
Read
through all instructions before starting, so you'll know what to look for.
Face
east.
If
it is daytime, flow time forward until it is dark and the stars are
visible. Keep time moving fast until you
see a band of light across the sky.
That's the Milky Way. To ensure
that you see the Milky Way clearly, go to Viewing Options (icon or F4) and turn
light pollution down to option 1 (as low as it will go). Then stop the flow of time. If dawn approaches, you can press “a” to
turn daylight off. If the Sun rises and
produces glare in the sky, you can turn the Sun off by going to the Viewing
Options window (icon or F4) and turning the planets off in the upper right
box. Turning the planets off also
extinguishes the Sun.
Q1. What city do you live in? Is it in a metropolitan area or is it far
from any large city?
Q2. Does the Stellarium sky resemble what the sky
looks like from your neighborhood? Can
you see the Milky Way from your neighborhood?
If not, have you ever seen the Milky Way?
In
urban areas, poorly designed lighting wastes a lot of light, energy, and money
by allowing much of the light to escape upward. This makes the sky very bright
and severely limits what you can see in the sky. To see the effects of this “light pollution,”
do the following:
Go
back to the Viewing Options window and increase the light pollution by
increasing the number. The options go
from 1 (no light pollution) to 9 (severe light pollution). Increase the light pollution until the sky
approximately matches the sky that you can see from your home.
Q1. How did this change the appearance of the
sky. For example, at what setting does
the Milky Way disappear?
Q2. At what setting does the sky approximately
match what you can see from your neighborhood?
If you cannot see the Milky Way from your neighborhood, where could you
go to see a sky with no light pollution?
You
can help reduce light pollution (and save money) by encouraging the use of
“full cutoff” light fixtures that direct the light only downward where it’s
needed.
Click
the quit icon at the right of the bottom toolbar or quit with ^Q.
Planetarium
Activity #7: Blast Off From Earth
Read
through all instructions before starting, so you'll know what to look for.
Go to “Viewing Options” (icon or F4) and set the following:
Under Sky: turn
atmosphere off (“a”); set light pollution to “1” (lowest value); check “Show
planet orbits”; under Labels and Markers, slide the planets bar all the way to
the right so that many objects will be labeled.
If you want more stars to be labeled, also slide the Stars bar a bit to
the right (not too far or too many stars will be identified).
Under Markings: check
“Ecliptic line”
Under Landscape:
uncheck “Show ground” and “Show fog”
Flow time forward until the Sun is centered in the window
and you can see many planetary orbits.
Go to Location (icon or F6) and change your location from
Earth to Moon. Flow time forward and watch the planetary
orbits. Note when Earth becomes visible,
the stop the flow and center the Earth in the window by dragging. Flow time forward again and note how the Earth
moves and how its phases change.
Q1. Does Earth
display phases as seen from the Moon as the Moon does as seen from Earth? Why do we see these phases?
Next set your location (F6) to Mars and flow time forward
until the Sun is centered in the window.
Note the orbits of the inner planets.
From Mars, the Earth never strays very far from the Sun, just as Venus
behaves from Earth. Notice that the
Martian moons, Phobos and Deimos flash through the field as time flows forward.
Q2. How do the orbits
of the dwarf planets Pluto and Ceres and the asteroids (Pallas, Vesta, Juno,
etc.) appear with respect to the ecliptic (and the orbits of the major
planets)?
Next set your location to Jupiter and again note how the
orbits of the dwarf and minor planets differ from those of the major planets.
Q3. Do the motions of
the four Galilean satellites (Io, Europa, Ganymede, and Callisto) follow the
same trajectory with respect to the view from Jupiter?
Set your location next to Callisto, the farthest out of the
Galilean satellites. Time flows forward
until you see Jupiter fairly close-up.
If Jupiter doesn’t show up, that’s OK.
It doesn’t always show on the display for some reason.
Next, set your location to Pluto and time flow forward.
Q4. How do the
ecliptic and the orbits of the planets move as Pluto travels around the
Sun? Why do they move the way that they
do?
Finally, set your location to “Solar System Observer”. Move around and zoom in and out until you
locate the Sun. Zoom in until all the
orbits of the planets are visible.
Q5. Can you identify
the orbits of Neptune and Pluto? How is
the orbit of Pluto different from those of the major planets? What happens to Pluto during part of its
orbital period of 248 years (with respect to Neptune)?
Activity III. [16]
Please do ONLY ONE of the following:
Choice A: If you are
an observation enthusiast, view the “real” night sky at your current “real”
location. Identify any two stars or a
star and a planet. Please refer to the
Stellarium software for help with this and note
(briefly) what you found, including where and how. You can also use the planisphere that you
purchased to guide you around the sky (see below). Also specify the date, local
time, and your geographic location when you made the observations.
Choice B: If you have
problems observing or prefer not to, write down (in brief) four things that
interested you in the planetarium exercises in Activity II .
Night Sky planisphere:
The following is a description of
how to use a planisphere just in case you decide to acquire one.
Notice that there's a wheel that
turns. Around the outside of the wheel are dates. Outside of the wheel are
times of day (or night). If you turn the wheel so that the current date lines
up with the current time, the planisphere will show you what constellations are
visible and what part of the sky they are in. To match up the constellations
visible on the planisphere with the real sky, stand outside and hold the
planisphere over your head and oriented
in the right direction (so that “east” on the planisphere is toward the east,
“west” is toward the west, etc.). The easiest thing to do is to face South and
hold the planisphere over your head such that the North direction points toward
the North Star (Polaris). You may need a flashlight when using it outside at
night. Unfortunately, the average flashlight is bright enough to keep your eyes
from dark adapting so that you can see fainter stars. Therefore, it is recommended that you cover
the front of a flashlight with red cellophane when trying to make astronomical
observations. Several layers of the
clear red cling plastic wrap will work very well for this. You will ease the discomfort of your
observing greatly if you set up a lawn chair (preferably a lounge chair) and
tilt it back so that you can look up to the sky comfortably.
The Stellarium software (or any
planetarium program) can also be fun to use for help with observations. You can bring up the program at the correct
time for when you are observing, then print the sky and take the chart outside
to help you locate objects.