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===Moving Around the Sky===
===Moving Around the Sky===
Revision as of 18:51, 5 May 2011
At the bottom left of the screen, you can see the status bar. This shows the current observer location, field of view (FOV), graphics performance in frames per second (FPS) and the current simulation date and time.
The rest of the view is devoted to rendering a realistic scene including a panoramic langscape and the sky. If the simulation time and observer location are such that it is night time, you will see stars, planets and the moon in the sky, all in the correct positions.
You can drag with the mouse on the sky to look around or use the cursor keys. You can zoom with the mouse wheel or the page up/page down keys.
If you move the mouse over the status bar, it will move up to reveal a tool bar which gives quick control over the program.
When Stellarium starts up, it sets its clock to the same time and date as the system clock. However, Stellarium's clock is not fixed to same time and date as the system clock, or indeed to the same speed. We may tell Stellarium to change how fast time should pass, and even make time go backwards! So the first thing we shall do is to travel into the future! Let's take a look at the time control buttons on the right hand ride of the tool-bar. If you hover the mouse cursor over the buttons, a short description of the button's purpose and keyboard shortcut will appear.
|j||Decrease the rate at which time passes|
|k||Make time pass as normal|
|l||Increase the rate at which time passes|
|8||Return to the current time & date|
OK, so lets go see the future! Click the mouse once on the increase time speed button . Not a whole lot seems to happen. However, take a look at the clock in the status bar. You should see the time going by faster than a normal clock! Click the button a second time. Now the time is going by faster than before. If it's night time, you might also notice that the stars have started to move slightly across the sky. If it's daytime you might be able to see the sun moving (but it's less apparent than the movement of the stars). Increase the rate at which time passes again by clicking on the button a third time. Now time is really flying!
Let time move on at this fast speed for a little while. Notice how the stars move across the sky. If you wait a little while, you'll see the Sun rising and setting. It's a bit like a time-lapse movie. Stellarium not only allows for moving forward through time - you can go backwards too!
Click on the real time speed button . The stars and/or the Sun should stop scooting across the sky. Now press the decrease time speed button once. Look at the clock. Time has stopped. Click the Decrease time speed button four or five more times. Now we're falling back through time at quite a rate (about one day every ten seconds!).
Enough time travel for now. Wait until it's night time, and then click the Real time speed button. With a little luck you will now be looking at the night sky.
Moving Around the Sky
|Cursor keys||Pan the view left, right, up and down|
|Page up / Page down||Zoom in and out|
|Backslash (\)||Auto-zoom out to original field of view|
|Left mouse button||Select an object in the sky|
|Right mouse button||Clear selected object|
|Mouse wheel||Zoom in and out|
|Space||Centre view on selected object|
|Forward-slash (/)||Auto-zoom in to selected object|
As well as travelling through time, Stellarium lets to look around the sky freely, and zoom in and out. There are several ways to accomplish this listed in table above.
Let's try it. Use the cursors to move around left, right, up and down. Zoom in a little using the Page Up key, and back out again using the Page Down. Press the backslash key and see how Stellarium returns to the original field of view (how “zoomed in” the view is), and direction of view.
It's also possible to move around using the mouse. If you left-click and drag somewhere on the sky, you can pull the view around.
Another method of moving is to select some object in the sky (left-click on the object), and press the Space key to centre the view on that object. Similarly, selecting an object and pressing the forward-slash key will centre on the object and zoom right in on it.
The forward-slash and backslash keys auto-zoom in an out to different levels depending on what is selected. If the object selected is a planet or moon in a sub-system with a lot of moons (e.g. Jupiter), the initial zoom in will go to an intermediate level where the whole sub-system should be visible. A second zoom will go to the full zoom level on the selected object. Similarly, if you are fully zoomed in on a moon of Jupiter, the first auto-zoom out will go to the sub-system zoom level. Subsequent auto-zoom out will fully zoom out and return the initial direction of view. For objects that are not part of a sub-system, the initial auto-zoom in will zoom right in on the selected object (the exact field of view depending on the size/type of the selected object), and the initial auto-zoom out will return to the initial FOV and direction of view.
Stellarium can do a whole lot more than just draw the stars. Figure above shows some of Stellarium's visual effects including constellation line and boundary drawing, constellation art, planet hints, and atmospheric fogging around the bright Moon. The controls main tool-bar provides a mechanism for turning on and off the visual effects.
When the mouse if moved to the bottom left of the screen, a second tool-bar becomes visible. All the buttons in this side tool-bar open and close dialog boxes which contain controls for further configuration of the program.
Table below describes the operations of buttons on the main tool-bar and the side tool-bar, and gives their keyboard shortcuts.
|Constellations||c||Draws the constellation lines|
|Constellation Names||v||Draws the name of the constellations|
|Constellation Art||r||Superimposes artistic representations of the constellations over the stars|
|Equatorial Grid||e||Draws grid lines for the RA/Dec coordinate system|
|Azimuth Grid||z||Draws grid lines for the Alt/Azi coordinate system|
|Toggle Ground||g||Toggles drawing of the ground. Turn this off to see objects that are below the horizon|
|Toggle Cardinal Points||q||Toggles marking of the North, South, East and West points on the horizon|
|Toggle Atmosphere||a||Toggles atmospheric effects. Most notably makes the stars visible in the daytime|
|Nebulae & Galaxies||n||Toggles marking the positions of Nebulae and Galaxies when the FOV is too wide to see them|
|Planet Hints||p||Toggles indicators to show the position of planets|
|Coordinate System||Enter||Toggles between Alt/Azi & RA/Dec coordinate systems|
|Goto||Space||Centres the view on the selected object|
|Night Mode||[none]||Toggle “night mode”, which changes the coloring of same display elements to be easier on the dark-adapted eye.|
|Full Screen Mode||F11||Toggle full screen mode.|
|Flip image (horizontal)||CTRL+SHIFT+h||Flips the image in the horizontal plane. Note this button is not enable by default. See section [sec:imageflipping]|
|Flip image (vertical)||CTRL+SHIFT+v||Flips the image in the vertical plane. Note this button is not enable by default. See section [sec:imageflipping]|
|Quit Stellarium||CTRL-Q||Close Stellarium. Note: the keyboard shortcut is COMMAND-Q on OSX machines|
|Help Window||F1||Show the help window, which lists key bindings and other useful information|
|Configuration Window||F2||Show the display of the configuration window|
|Search Window||F3 or CTRL+f||Show the display of the object search window|
|View Window||F4||Show the view window|
|Time Window||F5||Show the display of the help window|
|Location Window||F6||Show the observer location window (map)|
The Object Search Window
The Object Search window provides a convenient way to locate objects in the sky. Simply type in the name of an object to find, and then click the “go” button or press return. Stellarium will point you at that object in the sky.
As you type, Stellarium will make a list of objects which begin with what you have typed so far. The first of the list of matching objects will be highlighted. If you press the TAB key, the selection will change to the next item in the list. Hitting the RETURN key will go to the currently highlighted object and close the search dialog.
For example, suppose we want to locate Mimas (a moon of Saturn). After typing the first letter of the name, m, Stellarium makes a list of objects whose name begins with M: Mars, Mercury, Mimas, Miranda, Moon. The first item in this list, Mars, is highlighted. Pressing return now would go to Mars, but we want Mimas. We can either press TAB twice to highlight Mimas and then hit RETURN, or we can continue to type the name until it is the first/only object in the list.
The Help window lists all Stellarium's key-strokes. Not that some features are only available as key strokes, so it's a good idea to have a browse of the information in this window.
The About tab in this window will show licensing information, and a list of people who helped to produce the program.