NightSky 2.2
Programmed by Dan Jensen. Please send your questions and comments to him at djensen@kaweah.com.
Programmed by Dan Jensen. Please send your questions and comments to him at djensen@kaweah.com.
NightSky (previously named "HarpStars") is a planetarium for the Macintosh. Through its windows you can see where the stars are tonight, next month, or any other time. You can view up to over 50,000 stars (if you acquire a big enough data file). You can see where the sun, moon, planets, galaxies and other deep space objects are. You can view all the constellations, some of which I've exercised some poetic license with. You can add, edit, and remove stars and constellations if you wish.
NightSky updates its sky displays every several minutes to keep up with the sky outside. If you want to control which part of the sky is displayed, you can move to another part of the sky with several methods:
1) Use your mouse to drag a rectangle to "zoom in" on the region contained by that rectangle. If you draw a big enough rectangle, you will "zoom out".
2) Use the scroll bars to move around.
3) Use the RA & Dec menus to move to another part of the sky. Use the "Width" menu to set the "view angle".
4) Select the "Position" or "Time" item from the "Settings" menu, and enter a specific set of numbers into the fields in the dialog box that appears. If you select "Tonight" from the "Settings" menu, the display will show the sky for 9 pm tonight. Selecting "Current" tells NightSky to switch back to its "real time" mode.
Do you want to see what the sky looks like from another star? Just activate the "View from Star" feature and click on a star. Once you go, however, it may not be easy to get back, so just close the current window if you get lost. Open a fresh window and you'll wake up safely on mother earth.
You can have up to five windows open at a time, each with its own view.
If you see too many or too few stars, you can use the "Bright" menu to fix that.
Turn on the "twilight" feature if you want to see where day and night are. There is also a "magnitude density" feature if you want an alternative way of seeing star light (your Mac must have color to use these special display modes). There is also an "Auto Const's" mode in which NightSky attempts to draw its own pseudo-random constellations.
If you want to save what you see in a window, you can save it as a PICT or PNG file, which you can open from NightSky at any time in the future. You can also print the contents of a window.
NightSky runs on Power Macintoshes and also older 680x0 Macs with an FPU (floating Point Unit). NightSky will also run on most 68020/30/40 Macs running "Software FPU".
A significant performance gain can be achieved on Power Macs by using the "MathLib" shared library.
Although NightSky is meant to be run on a color display, it will run on a monochrome display with limited functionality.
NightSky is designed to safely abort when a user attempts to load more data than the application's allotted memory can support, but sometimes a bus error will occur under such circumstances, so it is important to provide NightSky with enough memory (using the "Get Info" selection from the system's file menu). Here are some examples of the minimum memory required to load certain data files (not including system requirements):
data file amount minimum
of stars memory
stars3k.dat 3000 1300 kb
stars5k.dat 5000 1900
stars10k.dat 10000 3300
Only one data file (stars3k.dat) is provided in network distributions to minimize download time. Larger sets can be downloaded.
Color features like "twilight" & "magnitude density" require that even more memory be allotted before running NightSky. Opening more than one window will obviously require more memory.
NightSky 2.2 is shareware. If you find NightSky to be useful, please don't hesitate to send $15 to Kaweah Software, PO Box 7381, Menlo Park CA 94026.
File Menu -
Select "Save" to save any changes that you have made. To save to a new file, select "Save As ...".
Select "Make Image" to save the current screen as a PICT or PNG file.
Select "Print ..." to print the current window. Select "B&W Printing" to toggle color printing on and off.
Edit Menu -
The first three options on this menu set the edit mode for any time a point in the active window is clicked. In "add" mode, a new star is created at the place clicked. In "remove" mode, clicking a star will cause that star to be removed. In "modify" mode, clicking a star will enable you to edit its data.
If "Star Name" is the active edit mode, clicking a star will cause its name to be displayed.
The next two menu options determine the effect of dragging the mouse pointer across the display window. Normally, dragging the mouse pointer draws a zoom/select box, which changes the portion of the sky being displayed.
If "Link Stars" is selected, the mouse pointer creates a permanent link-line between two stars (you must begin at one star and end at another). Hold down the
If "Draw Freely" is selected, you can use the mouse to draw temporary lines which will last only until the display is redrawn.
If "View from Star" is the active edit mode, clicking a star will cause the display to reflect what the sky looks like from that star.
Right Ascention Submenu -
Set the right ascension quickly to any of 12 longitudinal slices (2 hours each). For terrestrial data, each longitudinal hour represents 15¡.
Declination Submenu -
Set the declination quickly to any of 13 latitudinal slices (15¡ each).
Select "Exact Position" to use a dialog to set your viewing position.
Width Submenu -
Set the width of the field of view, while staying at the same view position.
Select "Find Star" to search for a star by name. The search is case-sensitive, and will find the brightest star (or the most populous city) with a name that contains the indicated string.
Bright Menu -
Set the minimal brightness of stars to be plotted on the screen (a larger integer represents a dimmer star). As dimmer stars are allowed, bright stars will appear larger.
Settings Menu -
The first three items in this menu determine whether (1) messier objects, (2) constellations, and/or (3) automatically-generated constellations are displayed.
The fourth item, "Star Names", determines whether star names are displayed.
"Status Line" toggles the mode of the status bar at the foot of the current window. In the default mode, position and time are displayed. The alternative is to display the name of the constellation at the middle of the display.
The next three options are only available with color Macs. The "Color" item toggles display color on & off. "Twilight" & "Mag. Density" are available only if display color is on. "Twilight" is intended to show day and night across their respective portions of the sky. "Mag. Density" maps the varying brightness of regions in the current display.
The last five items can be used to set the time and time zone.
Projection Menu -
Four optional map projections, so that data can be represented more flexibly:
The projection will automatically change under circumstances where the current projection does not apply well to the latitudes being displayed.
NightSky can be downloaded directly from Kaweah Software.
You can download NightSky from Apple Computer's Info-Mac mirror site.
If this source is currently unavailable, NightSky can be downloaded from most other Info-Mac mirror sites. Look for "nightsky-22.hqx" in the "sci" directory.
NightSky is also available in America Online's Astronomy forum.
Please address comments about this page to
djensen@kaweah.com
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Please visit the Kaweah Software home page.
updated December 11, 1995
Polar: Azimuthal Equidistant
Plate Carée: Cylindrical Equidistant
Mercator: Cylindrical Conformal
Orthographic: Azimuthal Perspective
Acquiring NightSky
Extended Data Sets