What the Sky window initially presents you with is the entire celestial sphere for the preset location, with South at the bottom, East at the left. Vega will be the initial focus for northern observers and Canopus for the southern hemisphere. Stars plotted in dark green or grey lie below your horizon: they have set, not yet risen, or may never rise at your position.
Coeli's virtual Earth revolves in real time, and the apparent motion of the stars is from left to right when facing south.
In pre-5.0 versions of Stella, left-clicking on an object has the same effect.
Dragging the mouse over the sky with the left button held down is like looking up at the stars and turning your head - up, down, left, right, or any directional combination. Coeli's sky is totally 'plastic' and malleable, responding with the greatest sensitivity to the mouse and re-centering itself with every movement. There's nothing like Drag Mode for the experience of 'being there'. Best enjoyed in full screen mode!
Single clicking on any object with the left button will accomplish the same as passing the mouse over it in auto-search mode. Data for that object will be displayed and updated, with this important addition: the object clicked will be marked as the current selection.
Single clicking anywhere in the sky window with the right button will call up the comprehensive popup context menu, from which just about all Coeli's major functions and settings can be selected.
Double clicking on the Sun, Moon, or any planet or DSO will link you directly to the relevant page of SEDS' exciting online Messier and Nine Planet tours. Your browser will be activated to download and display the Web pages. (Version 4.90 and above)
Your display's default celestial projection is an azimuthal Equal Area, [F3], centered on your zenith. It is of the type used by planetaria the world over, so it is in good company, but if you happen to desire a change, there are three more to experiment with: Equidistant [F2], Stereographic [F4], and Orthographic [F5]. When you gain a little more experience using this Coeli software, you'll want to begin experimenting with contrasting viewpoints too.
Start by pressing [H] for a horizon view of the southern sky. To traverse through the 360 degrees of the compass, access the traverse and elevation tools with [ctrl][D] or [ctrl][E]. The tools accomplish the equivalent of dragging with the left button held down, and are really only useful if you prefer not to be in Drag Mode. Alternatively, you may prefer to enable auto-centering at the outset with |Viewpoint|Projection|Auto-center| thus doing the job of the traverse and elevation tools automatically each time you click on a new object. With its often abrupt switching of view, this setting can prove disorienting on occasion, especially if you have not yet attained full familiarity with your local celestial geography! As with all things Coeli, it will therefore pay to experiment a little.
[Z] will return you to a zenith view, but at the new line of sight you traversed with the tools.
It is worth stressing that after any operations which somehow change your viewpoint, pressing [F12] immediately is the safest way to ensure an accurate display of all stars visible at the current magnification. For extra responsiveness, some operations do not incorporate this process.
When ZDNet referred to Stella 2000 in this way, they were not exaggerating...
For Coeli's representation of the sky, realism has been the watchword, and we are confident that this ideal has been achieved. Color is the key. The essence of a star is its color, linked intimately to its spectral class. Astronomers have given all the brighter stars a color index, and the program's palette is based on it. So, if you see a deep crimson in your Coeli display, you can be certain that it is an M, or a piercing white an F, or an orange like Arcturus or Aldebaran a K. Not that this may matter to you, but it will to many. Observe the true heavens on a crystal night - each star has its tint, each planet its hue, albeit cast over with tropospheric blue.
The program itself provides these keys for tampering with colors: [B] , [D] , and [R].
[B] brightens (lightens) the palette uniformly, giving a washed-out effect, and finally washes color out completely. [D] achieves exactly the opposite, darkening - and thereby deepening - all the colors. Unrealistic, as if seen through sunglasses, but you may find it a change. It at least reveals a star's underlying 'character', subleties that the brightness may have hidden.
By default, [a]uto-resolution of stars is switched on. What this means is that you only begin to see the dimmer stars as you increase your resolving power (change to binoculars/telescope), in imitation of reality. Initial magnification is negative in order to encompass the entire sky. Zoom down to zero magnification to receive an impression of the sky as seen on a clear night by the naked eye. To adjust the number of stars visible at any given magnification, press [+] or [-]. Auto-resolution will need to be disabled with [a] if you wish your changes to survive any zooming or unzooming operations you might perform subsequently.
The Celestial Sphere modeled by your Coeli display revolves in real time, updating itself without your intervention. Ever yearned to see a heliacal rising of Sirius on an unexpectedly clear southeastern horizon when all the zenith is thunderous overcast? Your Coeli software plots the moment of its rising, so effectively you're permitted to observe it twice - first on Coeli's virtual heavens, and then outside in the strangely silent dawn cold where Sirius twinkled ominously red for a fleeting instant in the atmospheric turbulence of sea-level. The Stella 2000 family even shows scintillation (twinkling) for that extra touch of realism.
Incidentally, if the relative positions of some stars begin to appear a little scrambled (as they may do during frequent use of functions which change your viewpoint in some way) , simply press [s], [n], [e], [w], or [F12] depending on your preferred orientation, for a full recalculation of all altitudes and azimuths. In any event, the program's ongoing calculations will eventually get around to returning every star to its correct position.