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School
Cerro Coso Community College *
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Course
C125
Subject
Astronomy
Date
Apr 3, 2024
Type
Pages
21
Uploaded by ColonelInternetHare13 on coursehero.com
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Name:
Melissa Marquez
Due Date: Saturday, February 10 by 11:50pm
Objectives:
Learn how to set your Location in Stellarium
Learn how to set your Date and Time in Stellarium
Learn how to change the Rate at which Time passes in Stellarium
Learn how to Look around in Stellarium
Learn how to Find Astronomical Objects in Stellarium
Observe different types of Solar Eclipses
Observe how Solar Eclipses affect your daytime sky
Observe how your location affects the type of Solar Eclipse you see
Section 1.1 - Starting Stellarium:
Start up
Stellarium
on your computer. You should find it located in the “Programs Files” folder in Window’s “Start Menu” or inside the “Applications” folder in MacOS. Double-click on its name and/or icon to start the program. When it finishes opening, you should see an image of a horizon with green grass below and sky above.
Before we begin the lab activity, two useful things to know are:
(1.) You can quit Stellarium by clicking the "Power" button:
which is located on the right-hand side of the floating icons that exist on the bottom of the Stellarium screen.
(2.) You can change Stellarium’s screen size by clicking:
which makes Stellarium's screen minimize to a smaller window on your computer. This button is located in the middle of the floating icons that exist on the bottom of the Stellarium screen.
Lab 2: The Basics of Stellarium
and
Observing Solar Eclipses
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Section 1.2 - Setting Your Location:
To simulate your night sky, Stellarium must know your location’s latitude and longitude on Earth. During the semester, you will see that your latitude determines:
(a.)
what regions of the Universe you can look at
For example, people living in Northern latitudes can easily see the North Star (Polaris) but people living in Southern latitudes can never see the North Star.
(b.)
the length of time that astronomical objects remain in your sky before they set below your horizon
For example, people living near the mid-latitude city of Bakersfield, California have the Sun in their sky for about 14.5 hours on the first day of Summer, while people living near the high-latitude city of Nome, Alaska have the Sun in their sky for about 21.5 hours on the first day of Summer.
(c.)
the angular orientation of your sky’s rotation relative to your horizon. For example, people living near Bakersfield see astronomical objects travel across their sky from East to West along pathways that are tilted toward their Southern horizon, while people living on Earth’s equator see celestial objects travel across their sky from East to West along pathways that are not tilted.
Meanwhile, your longitude mainly determines the time it is at your location. For example, people living near Bakersfield’s longitude obviously do not share the same time of day with people living in Tokyo, Japan even though both cities have very similar latitudes.
The following steps tell Stellarium your latitude and longitude location on the Earth so that it can simulate what your sky looks like at your location. Note that for simplicity, our default location for many of our lab activities this semester will be Bakersfield, California.
For students living in Southern California, using Bakersfield as your default location will produce simulated skies that are not drastically different from your actual sky. As you will see though, if you desire to simulate your actual sky, it is easy to do. To simulate your actual sky, all you have to do is set Stellarium’s location to your city’s latitude and longitude.
Steps for Setting Your Location within Stellarium:
(1.) Position your cursor on the lower left side of Stellarium’s main screen to bring up Stellarium’s two pop-up menus. (2.) You should see a “vertical pop-up menu” and a “horizontal pop-up menu” that look similar to this:
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(3.) On the vertical menu, find and click the “Location window” button, which looks like:
(4.) You should now see a “Location window” that looks like:
(5.) Here, we want to change our location to Bakersfield
. The easiest way to do this is to search for Bakersfield in the database of cities that Stellarium remembers, which is shown on the upper right-hand corner of the Location window. Each city in the database has its latitude and longitude already stored within Stellarium, so you do not have to enter these values yourself. These values are shown on the lower left-hand corner of the Location window.
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To find Bakersfield in the database, first click the “Region” option on the lower right hand side of the window, then select the “Northern America” option. Now, click the “magnify glass” symbol:
which is located at the bottom of the list of city names. This option allows you to type in the name of the city you are searching for. So, after clicking the “magnify glass,” type in the word “Bakersfield”.
You should see that the only city option in the list is now “Bakersfield, Northern America”:
(6.) Click Bakersfield’s name in the list. You should now see that the “red arrow” in the Location window’s world map is now pointing at the location of Bakersfield. You should also see that the latitude and longitude have now changed to Bakersfield’s latitude and longitude:
Latitude: N 35° 22' 23.85"
Longitude: W 119° 1' 7.35"
(7.) Once you verify that you are at Bakersfield’s location, click the small “Use current location as default” box located on the lower left-hand side of the Location window. This will ensure that when you start Stellarium it automatically begins at Bakersfield’s location. (8.) Also make sure that the:
“Use custom time zone” option is NOT turned on
“Enable daylight saving time” option is turned on
These options are located on the lower right-hand side of the Location window.
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(9.) You can now exit the “Location window” by clicking the “Location window” button again, which looks like:
Note that most large, medium, and small cities throughout the world are stored in the database. So, whenever we have to change our city in an activity, we will just go back to the Location window and repeat the steps we just did, but search for the new city instead of Bakersfield. Also, you can easily do this in your free time if you are curious about simulating your own location’s sky. Note though that if you live in southern California, your local sky will essentially look like the sky from Bakersfield.
Section 1.3 - Setting Your Observation Date and Time:
When simulating your sky within Stellarium, you can select whatever year, day, and time you want to view your sky at. The following steps show you how to set your simulated year, day, and time.
Steps for Setting Your Date and Time within Stellarium:
(1.) Position your cursor in the lower left corner of the main screen to bring up the pop-up menus. In the vertical menu, find and click the “Date/Time window” option, which looks like:
(2.) You should see a “Date/Time window” that looks similar to:
Here, the first three numbers are:
Year / Month / Day
and the second three numbers are:
Hours / Minutes / Seconds.
Note that Stellarium displays time using a 24-hour clock (i.e. it does not use AM/PM). For example, the time 20:11 is equal to 8:11 PM. An easy way of converting from the 24-hour clock to the AM/PM clock is to subtract 12 hours from any time greater than or equal to 13:00 . For example, if the time is 21:00, then it is 21:00 – 12:00 = 9:00 PM. One complication is that for times between 00:00 and 01:00, it is the 12 AM hour. For example, 00:15 is 12:15 AM. Meanwhile, if you need to convert from an AM/PM clock to the 24-hour clock, you just add 12
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hours to any time greater than or equal to 1:00 PM. For example, if the time is 5:30 PM, then it is 5:30 PM + 12:00 = 17:30 . The one complication is once again the 12 AM hour, which corresponds to times between 00:00 and 01:00 in the 24-clock. For example, 12:45 AM is 00:45.
Question 1
: What are the times 00:45, 01:22, and 17:25 in the AM/PM clock?
The following times would convert to 00:45=12:45, 1;22=1:22 am, 17:25=5:25 pm
Question 2:
What are the times 12:35 AM, 10:55 AM, and 10:28 PM in the 24-hour clock?
The following times convert to: 12:35 =00:35, 10:55= 10:55, and lastly 10:28=22:28
(3.) To change the Date and Time in the “Date/Time window,” you have two options. The first option is to simply click the small “up” or “down” arrows above or below the number you want to increase or decrease. The second option is to click the number you want to change and then type in the number you want.
Play around with the “Date/Time window” by changing the year, month, day, and time.
Question 3:
What is the furthest year in the future that Stellarium can simulate?
(Hint: The year has a lot of nines in it.)
The furthest year in the future that Stellarium can simulate is 99999!
Question 4:
What is the furthest year in the past that Stellarium can simulate?
(Hint: In Stellarium, years before “year zero” have a negative math sign in front of them. So, Stellarium treats BC or BCE years as negative numbers and AD or CE years as positive numbers. The furthest Stellarium can simulate in the past will have a lot of nines in it and a negative sign, meaning BC or BCE.)
The furthest year in the past that Stellarium can simulate is BC!
Section 1.4 - Setting the Rate at which Time Passes:
Stellarium not only allows you to change your year, day, and time; it also allows you to change how fast time moves forwards or backwards. The following steps show you how to change how fast time moves forwards or backwards.
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