DSO is a freeware astronomical program for Palm OS devices that should help to plan observations of deep sky objects. The program allows to search for objects in the NGC/IC database by the object
minimum dimension
availability (i.e. its altitude at the particular time and location should be above some minimum)
type (galaxy, globular cluster, nebula etc.)
visibility (log(C0/C)) in particular telescope according to the visibility concept developed by Jose Torres or maximum magnitude
You could also limit search to Messier, Caldwell or Hershell 400 objects
Features
performs search of NGC/IC objects to be observed
performs search of closeby NGC/IC objects in the vicinity of a specified one
exports search results directly to Planetarium
calculates visibility for any object and graph the result
creates an observation plan
locates the object for equatorial mounts in 'manual go to' style by calculating the number of turns of RA and DEC handles from some star or other DSO
locates the object for dobsonian mounts in 'manual go to' style by calculating its azimuth and altitude
views other people observation logs (in Russian, from www.astronomy.ru)
Changes from version 1.0 to 1.1
IC database and object names are added
direct export of search results to Planetarium instead of Memo
search of closeby NGC/IC objects
ability to view Planetarium observation logs
night mode works correctly with Dynamic Input Area
creation of an observation plan
manual location of objects
viewing external observation logs
Changes from version 1.1 to 1.2
synchronization of objects with Planetarium when switching between porgrams
digital setting circles for Dobsonian mount
loading/saving observation lists
ability to make comments on objects in the detail window
integration with NGCIC database for RoadLingua
Download
DSO ver 1.1DSOLogs.rar This is the file in Russian with external logs from www.astronomy.ru. Install it only if you speak Russian
Main Screen
Displays the list of objects you searched for. On the first run it is blank. Set preferences (Option / Pref (1), Pref (2)) and then run search Object/Search
You could either see all search results or search results by constellation by tapping the trigger
Press Details button (or central button on Tungsten devices) to see object details. You could change object number (e.g. enter 404 for NGC objects, i124 for IC objects, m12 for messier objects and c23 for Caldwell objects), get telescope detection curve (see below under Object / Visibility), see the object log (if thre is one in Planetarium) or export the object into Planetarium. Pressing Add button adds an object into observation list. The program automatically search for a close bright star as a reference. You could later change that if you wish. If you switch to NGCIC database for RoadLingua from Detail window, the selected object is automatically chosen and you could have a look at its photo.
In the Detail window you could go to Menu/ListView to have a place for written notes about the object appear. You could make necessary advance notes on the objects and then see them when going through your observation plan.
The program displays + at the end of a line if there is an observation log for an object in Planetarium within a specified time range in Pref (3). To see the log press Details and then Log. The program also marks objects for which it has external observation logs in DSOLogs. To see them press Details and then Menu/ExtLog
Option / Pref (1)
Aperture: aperture of your scope in millimeters
Pass through: indicates how much light comes through your telescope. 1 stands for 100%. Indicatively, use 0.9 for refractors and 0.7 for reflectors
LM: limiting magnitude of the stars at your location (e.g. 6.0). LM is actually used to calculate sky surface brightness to estimate object visibility. LM is used for calculation only if SB=0 (see below)
SB: sky surface brightness in magnitude per square arc second used to estimate object visibility. SB value has a priority over LM, i.e. if SB is different from zero SB is used, otherwise LM is used
Focus: focus distance of your telescope in millimeters
Ep1 - Ep4: focus distance of your four eyepieces
OC: Open cluster
GC: Globular cluster
Gxy: Galaxy
PN: Planetary Nebula
OC+Neb: Open cluster + nebula
Neb: Nebula
SNR: Supernova remnant
Lat: Latitude. + for north, - for south
Lon: Longitude. + for east, - for west
LST start: local sidereal time (in hours) of your observation start
LST finish: local sidereal time (in hours) of your observation finish
MinAlt: minimal altitude of the object during your observation session
MinDim: minimum dimension of the object allowed
Press LST to calculate sidereal time. Select date, time, time zone and whether daylight saving time is applied. You could set calculated time as LST start and LST finish
Option / Pref (2)
Blackwell filter. Allows to run search on the basis of visibility. Detection limit sets lower threshold on visibility (i.e. if you set -0.1 as detection threshold all objects with visibility below -0.1 are blocked). Use detection limit of 0.2-0.3 to search for bright objects, -0.1 to include dim objects. Comment: if you run search with LM=4.5 you get no objects found. This is because visibility concept assumes that DSO objects have uniform surface brightness which is certainly not the case e.g. for bright messier objects core of M31, M13 could be seen under these conditions
Max Magnitude filter. Use this to search by the maximum magnitude, not visibility
No filter. All objects satisfying conditions in Pref (1) will be found
IC. Select/deselect to include/exclude IC database from search
Closeby. Select to search for NGC/IC objects in the vicinity of a specified one. Criteria selected in Pref (1) and Pref (2) will also apply to this search. This option is convenient if you want to see whether there are any other objects to look at after you found a specified one. Usually you need to select weaker search criteria in Pref (1) and Pref (2) as well
Select Messier, Caldwell, Hershel 400 if you wish to limit search to these catalogs only
Export Category. Select Planetarium object category for direct export of search results (Planetarium/Options/Objects/popup list in the top right corner). If you do not have Planetarium installed on your device this option is not displayed
Option / Pref (3)
RA, Dec turns. Enter the number of turns of your RA, Dec handles so that your mount makes a complete 360 degree turn around RA, Dec axis. For CG-5 Celestron mount the number is 144 (this is an analog of digital setting circles for equitorial mount).
Log Start, Log End. The program reflects observation logs only within the specified time range. This helps to plan your observations by quickly seeing, for example, what you have observed during the last week etc.
Planetarium sync. If chosen, Planetarium centers its screen on the last object in DSO when switching between programs
Eqt mount/Dob. Choose your mount type for digital setting circles calculations
Option / Night Mode
This turns your screen into Black / Red mode for color devices
Object / Visibility
Calculates visibility for any object
Plots telescope detection curve and object contrast in Graph. Y axis is log(contrast), X axis is log (angle) where angle is object minimum dimension multiplied by magnification. By touching the screen you could see visibility information for various magnifications
Object / Search
Performs search based on your settings in Pref (1) and Pref (2)
Object / Export
Exports search results directly to Planetarium. At the end of object name is its visibility, in the Planetarium Object Information window after objects dimension is position angle of the object
Object / ExportM
Exports search results into Memo in the following format (Object NGC number, dimensions, visibility, constellation).
Object / Locate (for equatorial mount - chosen in Pref(3))
Helps locate an object by showing number of RA and Dec turns from the given star or DSO. Fractions of RA/Dec turns multiplied by 60 (i.e. "minutes" of turn) are in brackets. Positive (negative) number shows that you need to turn your handle so that RA, Dec increases (decreases). Find the bright star close to your object. Find its HR (Yale catalog) number (e.g. in Planetarium). Enter the HR number of the star and NGC number of DSO. Polar align the mount (perfect alignment is not necessary, but the more precise the better). Point the telescope to the star and then turn your handles by the calculated number of turns (taking into account the signs). Check the procedure against the bright DSO first to get accustomed to it (and do not forget to turn handles in right direction!). From my experience this procedure helps to search for objects really quick (almost as quick as GOTO but not requiring all that electronics except for Palm handheld).
Start button starts a stop watch to calculate the number of RA turns to compensate for earth rotation. Use it to find a dim object back if you leave the mount for some time. Stop buttons stops a stop watch.
Add button adds an object to an observation list.
Object / Locate (for dobsonian mount - chosen in Pref(3))
Calibration. Center some bright star in the eyepiece. Press Now, the handheld memorizes the exact time, then enter its HR number (Yale catalog), its azimuth and altitude. Press calibrate and handheld will estimate necessary adjustments. It is sufficient to perform calibration once in the beginning of observing session. Both azimuth and altitude could be relative numbers. Be sure to (a) set your exact location and timezone in Pref(1), (b) set relatively exact Palm time and (c) make Dob base horizontal (I use level for this purpose). In my experience, I use Wixey device for measuring altitude and home made setting circle for azimuth measurement. This is sufficient to put the object into the center of eyepiece.
Press Manual button to get az/alt for any ra/dec. This is convenient when the object is not in NGC/IC database.
Object / List
Contains an observation plan. Reference star (or other DSO) is to the right, the object to the left. You may change the position of each line in the list (Up, Down), remove the line (Rem), get Locate form to find the object (Details), export list to Planetarium(Menu/Export), or Memo (ExportToMemo). The + sign indicates if the object has been seen within the specified time range (Pref (3)). By selecting the necessary time range you could see what part of your observation program has been performed and what is left. Menu/Find allows to search for the object within the list. You could also save and load observation plans.
Sources
http://www.uv.es/jrtorres/visib.html - method for calculating visibility
NGC/IC database. Acknowledgement: "The data used in this product, in whole or in part, is used with permission of The NGC/IC Project LLC - http://www.ngcic.org"
www.ppcompiler.org Pascal compiler used for compiling the program
Contact
e-mail:
Disclaimer
DSO for Palm is a freeware. DSO for Palm is copyright © by Leonid Vasiliev. DSO for Palm is provided "as-is" and without warranty of any kind, express or implied. I can accept no liability for data loss or any other problems caused directly or indirectly by the use of DSO.
Legal disclaimer
THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING (BUT NOT LIMITED TO) THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES INCLUDING (BUT NOT LIMITED TO) PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, LOSS OF USE, DATA OR PROFITS; OR BUSINESS INTERRUPTION HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE