As an avid amateur astronomer who also has interests in software development I’ve worked for many years, on and off, developing this planetarium software.
This program was designed to be a planetarium simulator with an emphasis on practical usefulness to the average amateur astronomer. As such, its function ranges from getting acquainted with the constellations and star names to planning observing sessions and controlling your Meade or Celestron telescope through the ASCOM telescope interface.
The latest trial version of Sky Planetarium handles the imaging requirements of many amateur astronomers too. With built in support for plate-solving, auto-focusing, and image acquisition. Cameras supported include ASCOM cameras, Webcams, and the Meade DSI series. Both Color and B&W cameras are supported with flexible de-bayering/de-mosaicing. The imaging console can save images in .bmp .jpg and several variations of the FITS file format. Cameras can even be shared between some tasks in Sky Planetarium (one camera doing both plate-solving and imaging for example.)
ASCOM feature support for telescopes, cameras, focusers, and filter-wheels is fairly extensive. Sky Planetarium also supports observatory operation features like shutter (or roof) control through the Dome interface and Safety Monitor integration. There’s even support for emailing status reports for unattended observatory operation. For telescopes, parking support is enabled if available as is homing (among other features.) For cameras support is included for gain setting, readout modes, binning, color, etc.
Goto Assist (GTA) helps goto telescope mount pointing operation by mathematically modeling the most common geometrical deficiencies of German Equatorial and Fork mounted telescopes. Once setup, a corrected location is calculated prior to issuing any goto commands to improve pointing accuracy. Specifically, the errors compensated for include: offset errors in RA/Dec on both sides of the meridian, polar alignment elevation, polar alignment azimuth, non-perpendicularity of RA/Dec axis/optics, tube flexture, Dec axis flexture, and (if applicable) fork flexture. Models can be saved and loaded. My OnStep telescope mount goto controller uses the same system internally and moving model coefficients between Goto Assist and OnStep is supported. This allows high performance models to be developed and then uploaded into OnStep where the improved pointing accuracy works with other applications (my Android App, Sky Safari, CdC, etc.)
The Points of Interest (POI) Sequencer allows lists of objects to be compiled for automated imaging runs. You choose the objects, exposure time, filters, etc. and the sequencer will move the ‘scope to each object and take the image(s.) Basic control of PHD2 for Autoguiding is also supported. If plate-solving is configured and enabled it will be used to refine the goto positions. The latest version has preliminary support for automated observatory control associated with this feature. The goal being to have the Observatory Control System (OCS) with its weather/safety monitoring manage open/closing a roll off roof while the POI Sequencer conducts fully automated unattended imaging runs as required to complete the acquisition of its list of objects.
The POI and plate-solving features can be used together to help with aligning OnStep either by its internal GTA (up to 9 align points) or using Sky Planetariums GTA which supports up to 200 align points.
For my OnStep telescope drive controller additional features are available over what ASCOM allows. These features include help with aligning the mount, real-time display of PEC playback and recording, reading and writing PEC data, tracking rate control, working with object libraries, status information, etc.
Some of its other features:
Maps from nearly any time. From the distant past to the distant future. See the precession of the Earth’s axis and how it affects the stars’ position.
The Location Tool allows you to quickly choose your geographic location from a map (or a list of cities.)
The Time Tool graphically shows sun rise/set and moon rise/set times along with Local time, UT, etc. It’s an analog clock and gives you a nice “feel” for the passage of time and it’s effect on the night sky’s appearance.
The Magnifier Tool shows you what’s under the cursor when you point to objects on the main map. This tool can mimic the view through various telescope/eyepiece combinations. It can also keep track of points of interest, which are locations you set on the map and can cycle through quickly with the number keys or via a menu selection.
The built-in BASIC scripting language includes the ability to pull data from catalogs, control a telescope and take images.
Other features include: a calendar of celestial events (computed on-the-fly), simulated sky glow during sun rise/set, fairly accurate planetary positions/depictions… including Jupiter’s moons and Saturn’s rings.
Naturally, help is available throughout the program.
And some more screen shots:
Downloads:
The most recent release is below, you can register here after trying it out:
The last stable release:
During installation Sky Planetarium will prompt you to install certain software before it’s installed:
The ASCOM Platform, for Observatory and Telescope control
Python 2.6.6, for Plate-Solving
Meade Envisage, for Meade DSI Cameras
Older versions:
Sky Planetarium version 3.27 (released Nov 4th ’13)
Sky Planetarium version 3.12 (released Mar 29th ’08)
Revision History
• 1-25-24: 4.76 Improvements to display of mount limits for cases of mounts w/Tangent Arm and Sector Gears.
• 12-7-23: 4.73 Higher speed image decode performance, especially for RGGB bayer.
• 11-27-23: 4.72 Fix for POI clear all bug.
• 11-21-23: 4.71 POI Grid tool better align point order for southern hemisphere users.
• 11-13-23: 4.70 ASCOM Control Pad form scaling design change.
• 11-1-23: 4.68 Added support for ASCOM Rotators. Reworked support for ASCOM Focusers. Updated ASCOM Control Pad.
• 10-28-23: 4.67 Added POI Grid tool, more fixes to GTA model upload, Assist points list now allows better editing.
• 10-23-23: 4.66 Fix for GTA model upload.
• 4-18-23: 4.65 Fix for GTA OTA sag term.
• 4-13-23: 4.64 Improved OnStep PEC data readout for slower connections.
• 2-8-22: 4.63 Added Alt/Azm mode Goto Assist support.
• 12-30-21: 4.62 Support for OnStep Unified ASCOM Driver version 1.0.19 and later.
• 12-6-21: 4.61 Better feedback of OnStep state in Telescope Dialog.
• 1-12-21: 4.60 User catalog upload now compatible with latest OnStep ASCOM driver.
• 7-24-20: 4.51 Magnifier now snaps to objects found. Planetary nebula default size slightly larter.
• 7-25-20: 4.52 Imaging Console multi-threading fixes.
• 7-26-20: 4.53 Imaging Console/ASCOM Telescope interaction fix.
• 7-28-20: 4.54 Additional telescope connect error info. in log.
• 7-30-20: 4.55 Corrected display artifacts displaying under-pole limits.
• 7-31-20: 4.56 Fix to prevent Imaging Console from saving previews.
• 8-16-20: 4.57 Fix for visual glitches w/Windows scaling of telescope dialog. Fix for Imaging Console camera sharing.
• 12-30-20: 4.58 Improved OnStep Axis1 min/max limit display.
• 1-12-21: 4.59 PEC export format locale override.
• 7-03-19: 4.41 Better PEC Upload logging. Better description of Polar Alignment Refine feature.
• 1-14-20: 4.42 Enhanced sequencer functionality. Support for +/- 180 degree OnStep meridian limits.
• 6-27-20: 4.43 Fixes and enhancements to sequencer functionality. Added sequencer option/interface to PHD2 Autoguiding. Fixed plate-solve so search radius works correctly (vastly faster solves.)
• 7-06-20: 4.44 Little fixes to plate solver UI.
• 7-18-20: 4.45 Many UI improvements, scaled dialogs etc, in support of modern high resolution displays.
• 7-20-20: 4.46 Additional UI improvements, in support of modern high resolution displays.
• 7-20-20: 4.47 Added support for showing OnStep Dec axis limits including Tangent Arm mounts.
• 7-22-20: 4.48 Improved performace. Improved stability for Magnifier tool. Magnifier now has an optional POI attached to the telescope position.
• 7-22-20: 4.49 More performace improvements.
• 1-7-19: 4.31 Fix for plate-solve system, no defaulting to telescope coordinates and added FITS file format save in 16 bit compatibility mode.
• 1-10-19: 4.32 Added Focustool with basic autofocusing support. A couple of fixes to the Autoguide system with a visual re-design also.
• 1-11-19: 4.33 Fix for plate-solve system, now sends to ansvr in .jpg format.
• 1-15-19: 4.34 Catalog import tool improvements/fixes. Now can delimit on “:” and automatically assign ID#’s where none is present in the catalog.
• 1-15-19: 4.35 Fixed for precession/nutation. Fix for catalog search case sensitivity.
• 1-29-19: 4.36 Improvements to the FocusTool and Autofocus.
• 1-29-19: 4.37 Change to allow telescope f-ratio of >= 1 as the lower limit in validation.
• 2-23-19: 4.38 Minor guide rate setting changes.
• 3-16-19: 4.39 Added telescope coordinate and telescope Axis1/2 rate display.
• 8-16-18: 4.21 Added support for display of RA/Dec from images in imaging console. Added support for goto or sync RA/Dec in imaging console. Fixed incorrect image size for first exposure when binning is enabled in imaging console. Finished move of rotation/PA from Camera properties (in Magnifier/Telescope Settings) into sequencer.
• 8-17-18: 4.22 Display/goto RA from images in imaging console should be more accurate esp. near celestial poles.
• 10-13-18: 4.23 Comms fix for Checksum IP.
• 10-17-18: 4.24 Improvements to OnStep user catalog support. Smoother operation during uploads/downloads. Faster catalog name changes. Additional catalog and object name checks (to remove LX200 protocol framing characters if present.)
• 10-30-18: 4.25 GTA solve consistancy with OnStep internal parameter space. Fixes to Astrometry.net plate solving. Fixes to goto/sync in image console.
• 9-14-17: 4.11 Minor Goto improvement.
• 9-19-17: 4.12 OnStep Rotator/De-Rotator support.
• 11-14-17: 4.13 Better logging of ASCOM Telescope exceptions.
• 11-14-17: 4.14 Support for switching between OnStep Focusers. Basic support for OnStep TMC2130 stallGuard configuration.
• 2-8-18: 4.15 Now graphically shows OnStep limits on map. Removed TMC2130 stallGuard feature, unworkable.
• 3-23-18: 4.16 OnStep two focuser support moved into focuser control (and Focuser ASCOM driver.) Support for OnStep Aux pin switching.
• 4-4-18: 4.17 Fixed Imaging Console directory selection utility.
• 4-25-18: 4.18 Added OnStep Aux switch and analog control.
• 5-17-18: 4.19 Added OnStep Meridian Flip Now feature support.
• 11-27-16: 4.01 Many little bug fixes and added some “Points of Interest” features. Mainly this involves displaying telescope/eyepiece and now camera fov indications on the main map which is useful for planning imaging sessions.
• 11-29-16: 4.02 Bug fixes for catalog import tool. Also added “Mv Unknown” type for importing catalogs without object magnitude information.
• 12-3-16: 4.03 Added OnStep “Preferred Pier Side” feature support.
• 12-4-16: 4.04 Sky guide (upper left corner) now has nicer appearance. Fixes to plate solving. Fixed color image file import, looks like canon cr2 files open now. Other minor improvements here and there too.
• 12-13-16: 4.05 Fixed NOVAS Site init. bug for “Planet” position accuracy improvements (esp. for our Moon.)
• 12-15-16: 4.06 Overhauled star display code for more realistic plots.
• 12-16-16: 4.061 Minor adjustments to star display code.
• 12-19-16: 4.062 Bug fix to star Flamsteed no’s. Cursor over star now shows more info. including Bayer or Flamsteed no.
• 12-20-16: 4.064 Re-enabled night vision mode (fixed numerous display issues with it.) Fixed telescope align problem with older OnStep versions.
• 12-23-16: 4.071 Reworked/updated help is now in html help format. Fixed date/time terms to agree with modern standards.
• 12-29-16: 4.072 More updates to the help file. Attempt to fix locale issue.
• 1-12-17: 4.073 Added “User Catalog” feature for easily adding objects. Changed installer to NOT overwrite the object database file so custom catalogs should be safe with upgrade installs now. Several minor bug fixes etc. too.
• 1-13-17: 4.074 Added “User Catalog” save/load CSV format.
• 1-13-17: 4.075 Added help to catalog import tool. Minor bug fixes/improvements and added AREA field type to import tool.
• 1-15-17: 4.076 Added AREA field type support to the plotter and Object Information dialog.
• 1-19-17: 4.077 Fixed Goto Assist bug I introduced about 6 months ago, had to do with OnStep LST synchronization. Added support for send/recv. of FF/TF/DF coefficients to OnStep so full pointing models are now supported in OnStep.
• 1-19-17: 4.078 Threw in some Goto Assist improvements and updated help: Goto assist models need info about pointing errors, goto calibration points, these can now be aquired automatically using the sequencer and plate solving.
• 1-21-17: 4.079 Goto Assist fixes. There were differences in the sign of coefficients found by the search routine in SP vs. what OnStep uses. Still need to test more, but searches seem to rapidly converge now. Modeling for EM10 run of six calibration stars (all acquired automatically see 4.078 notes) converged quickly to about 60 arc-seconds RMS.
• 1-22-17: 4.08 Fixes to plate-solve options “Sync and goto again” and “Guide to corrected location”. Updated help for plate-solving too.
• 1-22-17: 4.081 More Goto Assist fixes. Found a critical bug, looks better but still need to test.
• 1-25-17: 4.082 Goto Assist improvements. Speed and several other refinements, including keeping user from searching too deep while building models and the ability to show “Goto Calibration points” on the map to help visualize what the model is doing.
• 1-25-17: 4.083 More Goto Assist fixes. This was tested with real stars and is working very well for me now (with the model running in Goto Assist and with the model uploaded to OnStep.).
• 1-26-17: 4.085 Goto Assist UI improvements. Renamed offsets, Dec sign inversion for West offset vs. East allows same correction. Added option for high res. (0.1x FOV) view of model. Updated help to match.
• 2-3-17: 4.086 Goto Assist UI improvements. Added option more resolution options for examining the pointing model performance.
• 2-3-17: 4.087 Fixed recently introduced bug in Plotter (crashes SP.)
• 3-7-17: 4.088 Goto Assist, added “Auto Solve” feature.
• 3-8-17: 4.089 Fixed plate-solve bug involving southern declinations.
• 4-20-17: 4.09/4.091 Added ability to “Quick connect” to several ASCOM devices at once.
• 5-11-17: 4.092 Catalog import tool bug fix.
• 5-12-17: 4.093 User catalog import bug fix. Added ability to add POI’s from Find dialog.
• 7-10-17: 4.094 Added support for control of OnStep meridian flip pause, buzzer, and Declination tracking. Added safety check for starting align on parked mount.
• 7-14-17: 4.095 Better OnStep mount type detection and configuration of supported features.
11-11-16: 3.91 Fixes issues which resulted in Sky Planetarium needing to be “run as Administrator”. Fixed hover over solar system object accuracy issue. Better constellation name placement. Made some installer tweeks to keep from overwriting user settings.
11-14-16: 3.92 Fixes some annoying directory handling issues. Fixes to indication of preferred align locations for southern hemisphere users.
11-16-16: 3.93 Align status now resides in OnStep. This allows Sky Planetarium to follow/take over alignment from the Android App, etc.
11-16-16: 3.94 Added goto state query for OnStep.
4-15-16: 3.81 Drops the built in web-browser in favor of using the default windows web-browser. This is used by the object information dialogs and overcomes javascript problems with SIMBAD.
4-22-16: 3.82: Adds flush() to startup logging to help with debugging.
10-17-16: 3.83: Adds ability choose install location. Adds more flexible multi-star align support for OnStep. Fixes default path to python for plate-solves.
10-18-16: 3.84: Multi-star align fixes for OnStep.
10-27-16: 3.85: Added exception handling to bmp/jpg image format handling, this stops some really annoying crashes. Overall these image types still don’t work correctly, but “force-mono” option now allows some functionality. Not critical to OnStep function, all of this is for testing/learning features (Image File Camera).
11-2-16: 3.86: Added tracking rate display for OnStep.
11-9-16: 3.87: Display of object Hour Angle was added to info. dialogs. Minor image catalog handling improvements, including seperating user catalogs from built-in catalogs. This allows user image links (associated with objects) to remain untouched after an update install. I added/updated images for many objects.
Also, refraction rate tracking enable/disable buttons now send the correct commands.
Improved ASCOM focuser control, now supports older interface v1… Tested and working with my FLI PDF and OnFocus. Fixed bugs so ASCOM filter-wheel focus offsets work correctly. Also, added more focuser error reporting to the log.
Improvements to application message flow for better stability while imaging (my Quantix camera would periodically disconnect in the IC if OnStep was connected, this is fixed.)
• 7-2-15: Bug fix, Planetary moons/rings position.
• Fixed: Object catalog import, precession was broken. Added: support for more user defined object catalogs.
• Fixed: Bias frames are now forced to 0 seconds exposure, if a shutter is available it’s kept closed.
• Added: Tool-tip in PEC control to explain features.
• Added: Support for OnStep tracking rate settings. Preliminary OnStep PEC controls update to support latest features, ie. PEC Index.
• Added: Sequencer switched to non-modal window for easier control/use.
• Fixed: Sequencer controls imaging-console exposure number correctly now.
• Fixed: Sequencer warning (incorrect imaging parameter) no longer causes hang.
• Added separate window for telescope guide and focuser control.
• Fixed bug, guide actions sometimes don’t stop.
• Fixed bugs in POI sequencer.
• Fixed bug, settings file loading caused crashes – overflow.
• Fixed bug, internal .bmp file loading for better compatibility with images.
• Help system refresh, all the latest features are now documented and explained. I’m still using the ancient Microsoft Help format. The help viewer is still available to download for even the very latest Windows (8.1) and it does the job.
• Added code to allow the Points of interest Sequencer to actually Park the telescope if the option is set.
• Added features to Camera settings. Already included support for defining telescope optics has been combined with the Camera settings to allow calculation and display of CCD X/Y pixel and field sizes in arc units. This information will eventually be used in many places throughout Sky. For now, the Autoguiding dialog reports the guide star FWHM size/standard-deviation (of recent movements) in arc-seconds (“) and the Imaging Console reports the CCD field width and height in arc-minutes (‘).
• Added telescope current position bullseye and plate-solve markers to the magnifier.
• Plate-Solving, fixed problem with solve starting unintentionally when solve after goto is enabled. Fixed solves repeating.
• Autoguide, improved visualization of guide star. Added option to disable Dec guiding. Adjustable delay between exposures, historical centroid averaging (w/display.) Configure calibration movement amount (seconds of guiding). Various Declination guiding options (Off/Auto/North only/South only/Full).
• ASCOM Telescope, fixed OnStep PEC data handling errors (including better compatibility exporting to EQMOD’s PecPrep). Also fixed PEC int overflow error (StepsPerWormRotation.) Clear PEC data now erases the local buffer immediately. PEC data display updates immediately now for data clear and scale changes. PEC maximum buffer length extended to 3384 seconds.
• ASCOM Filterwheel, fixed error trying to query driver info. that’s unavailable in ASCOM standard.
• FITS file I/O, fixed a problem with int16 format saves.
• Fixed minor accuracy issue involving telescope mount coordinate coversions.
• Fixed object information for the Moon not working (trying to use NOVAS for the Moon, not currently supported).
• POI (Point of Interest) graphics changed for better presentation.
• POI’s accuracy improved, now using J2000 coordinates for about ±10 arc-second accuracy with Stars and Deep-Sky objects (use the “Add POI” button in the object information dialogs).
• First release with POI Sequencer, allows object lists to be built for automated gotos/imaging.
• Rewrite of Astrometry.net Plate-Solving code “objectized” for better Sequencer integration and eventual integration with the imaging console.
• Object database moved from simple file-based system to SQLite. Support for importing arbitary celestial object catalogs.
• Started a fix for an Auto Guiding problem caused by ASCOM PulseGuide blocking behaviour.
• Internationalization fixes.
• Additional logging of the ascom filter-wheel, focuser, and camera actions was also added.
• Fixed a bug; disconnection from some ascom devices wasn’t taking place when closing program.
• Also, fixes a bug with different versions of Windows not decoding Python command parameters consistantly.
• Fixed minor bug with telescope goto/sync accuracy.
• Added Goto Assist, when active applies to all telescope gotos/syncs.
• Fixed calendar/date pickers. Calendar was built with Delphi TCalendar component which is no longer available in my version of Delphi. Adapted TStringGrid to do the same thing.
• Added support for Imaging. Camera support includes: ASCOM b/w and color cameras (including CCD temperature control if present). DSI-I and DSI-II mono are tested, color and DSI-III support is experimental. VFW cameras (webcams, including SC modded LX type).
• Added support for ASCOM filter wheels.
• Added support for ASCOM focusers.
• Added Imaging Console for aquiring sequences of images, supports saving in FITS format (several integer and floating point types) and jpeg or bmp. Moves filter-wheel, adjusts focus, adjusts exposure length, and names files as you specify in sequence. Pre-processing can convert to B/W, invert/mirror the image, and handle various Debayer/Demosaic variations. When previewing the image in the console, you can shrink or stretch the image and overlay several different cross-hairs. Double-clicking gives a highly zoomed area for focusing help.
• Added Plate-Solving (through Astrometry.net). Figures out where you’re at in the sky, easy to setup and use.
• Added Auto-Guiding. Adapts to your camera/optical orientation and issues guiding commands to your ASCOM compativle mount.
• Added Telescope control features. Some are OnStep specific, for example PEC read/write and visualization. While others should work with any mount with an ASCOM driver that supports them. For example, the Home and Park/Un-Park commands. Another general purpose feature is the Goto Assist. This allows you to apply geometric corrections to an equatorially mounted telescope/mount and provides an “improved guess” at where your telescope is actually pointing in the form of an second bullseye marker on the map.
The main window now responds properly to being maximized (by loosing it’s scroll-bars) on XP and Vista.
• Fixed tool window visual corruption when Windows Start Menu is of large size.
• Updated help system to cover all current features.
• More updates to global location dialog, it now shows a thumbnail of the current horizon image. It’s also smarter about saving defaults, it asks to save if you changed something about the location.
• Fixed bug that caused the loss of image and note associations for celestial object catalog.
• Fixed bug that caused comets and asteroids to sometimes not be displayed in the magnifier.
• Fixed bug in “Celestial Object Information” dialog that caused descriptive text to be hidden when selecting the same object more than once.
• ky now disables access to all location and time setting mechanisms when a telescope is connected.
• Corrected problem with online downloading of elements from the MPC.
• More updates to globe menu/location dialog, misc. small improvements.
• Corrected Daylight Savings Time routines to current US standard.
• Corrected bug that caused “Early Tonight” time setting to be one day early.
• Corrected bug that crashed program on loading “Points of Interest”.
• Added support for online download and display of objects from POSS, etc.
• Misc. improvements for saving/loading Comet and Asteroid elements including online downloading of elements from the MPC.
2.0 Second version of Sky (Circa 1993). I think this was written in Borland Pascal 2.0
1.0 First version of Sky (Circa 1992). This was written with Turbo Pascal Windows 1.0 I believe.
Pre-1.0 version of Sky (Circa 1986). This was written in Modula-2 on an (4 MHz) Heathkit H89A running CP/M. I had a fancy graphics card that could plot star maps. It was a slow process. And yes, some bits of code in Sky are still relatives to this version.