Zaurus Sky Explorer

Zaurus Sky Explorer is a freeware planetarium in pocket size for all Java enabled devices. It is designed to use so few memory and cpu time that it can run on very low power devices, the even greater challenge was to oppose the saying that Java is slow. (and can not be used for such programs and still use an Objectorented design). This program proves that that it IS possible

The Name "Zaurus" in the name devotes the pocket planetarium to the Sharp Zaurus for witch it was originally designed. In the mean time it is now also available as Java-Application,Applet, web application

The Sky Explorer Applications are written by me and my wife Sabine Plunder. First inspirations came from Michael Nepp.

Consumer license

Zaurus Sky Explorer is a public domain program. It may be photocopied, duplicated and changed without limit. But it may not be sold in any way without permission of the programmer. All user are asked to email any requirements or suggestions to the programmer. That?s the only way a public domain program can develop.

Instructions

The available features of the Zaurus Sky Explorer are increasing day by day. So please look in the menu's and just try it. These where the original features:

• Display northern and southern sky
• includes 300.000 stars
• All Constellations
• 7700 Deep sky objects including there description
• 1000 minor planets and comets with automatic online update
• trajectorys of planets and comets
• uses only 1 to 4 Mb memory depending on the catalogs used
• a lot of functions to adjust the view of the sky to your needs
• control a telescope with the Zaurus

installation

Due to the full Java implementation it will run on any operation system. But when you ask me, i will always say use LINUX.

On the Zaurus just install the ipk. The Jeode virtual machine is not a requirement anymore also the J2ME[tm] Personal Profile for Zaurus is supported (it the default for all Zaurus after SL6000, but is also installable on the SL5500 (as i did). For telescope control (for now only celestron nexstar's) you will also need the java -serial-api package.

On a "big" computer just call "java -jar Zaurus -sky-explorer-xxx.jar". Any java version including 1.1.8 and later are supported. Also tested is the alternative java-vm is kaffe. (not on the zaurus help with that is requested)

windows-ce / pocketwindows is also supported you just need a java installed, then click on the jar.

For the applet version look in the page source for the link, and make jar+data-files available to the browser.

the main screen

When there is a internet connection at start time the current Comet and Minor planet data is downloaded, this will be done maximal ones a day. Wenn there is no connection the commets and minor planets of the last online start are used. Important there are no default minor planets so start it at least one time with an internet connection to get the Comet/minorplanet informations.

On the upper -right side of the sky view there is a list of buttons. Behind every button there is a menu. Every button groups a collection of functions.

in the middle of the lower side there are arrow buttons to move the field of view in up down left or right direction.

The screen itself is touch sensitive. so when somewhere on the screen is clicked the screen is rebuild centered around the selected position

O(bject) menu

depending on the field of view this menu is filled with the 20 most bright visible deep sky objects. When a deep sky object is selected the screen is re centered on it and a description of the object is displayed on the top of the screen.

the rectangle visible on the screen shows the area of the object. Of course are deep sky objects never rectangular but the limitations in memory and the availability of formated data forced me to this compromise.

M(ag) Menu

To adapt the (visible) brightness of stars to the current circumstances. lessen and increase brightness makes stars more or less bright. the mag limitation limits the drawn objects to objects that have at leased the selected brightness.

E(yepease Menu

To select the field here you can define your telescope/ Eyepiece. from this data the field of view is calculated. The real field of view is a little bigger so the sky explorer can draw it on the screen. All defined eyepieses are selectable in the menu.

S (constellations) menu

all available constellations are accessible from this menu. when one is selected the screen is re centered around the selected constellation. They are displayed in groups, to switch between them select next, previous or first.

F(unctions)

This menu is split in two because of the size of the submenu.

The image the Zaurus Sky Explorer presents can be adapted in many way. All available functions to change the way the image looks like are collected in this menu. All options in this menu that have a True/False state have check box before it that is checked when the option is set.

With the language entry you can switch language between, en=englisch de=german and fr=french (fr is not updated a long time..).

The character size entry enables you to switch between avaliable 10 character types and sizes.

Trajectory select the number of days for the trajectory of the selected object.

The save settings entry will recover all settings (that you have configured now) at the next start time.

When looking throb a newton telescope it is often very helpful to mirror the image horizontal or vertically to do this the first two menu points are available.

Often it is very helpfully to include the coordinates of the center of the image. When this option is set in the top of the image a text is included that represent the coordinates of the center in alt/az and dec/ra format.

The line color of the constellations can be adapted to light middle and dark color. to do this select the corresponding menu item.

Whether or not Deep Sky objects are displayed in the image depends on the next two menu items. Draw objects specifies if Deep Sky objects are drawn at all and "draw only selected object" specifies that only the object selected from the object menu is drawn, and all other's stay hidden.

To display eyepiese in the image select the draw eyepiese option. A circle with cross is drawn to specify witch part of the image you would see throe the eyepiese mounted on your telescope.

To customize the Language used in the menus and in the text displayed in the Image select the language menu. It rotates the available languages. "de,en,fr" means germen is the current language after selecting the menu item changes to "en,fr,de" and now the English is the current Language.

Because i got from Baader- Telescopes in Germany a cheap Nexstar-Mount i wrote a controller api for nexstar telescopes. To use this option you will needs a installed serial-api-for java. A cable to connect the zaurus/ PDA to the nexstar (don't forget to cross the control lines). Three telescope commands are available: "Follow the telescope" = Priodicly query the telescope where it is looking to and center the image around these coordinates , "Move telescope to" = Send the telescope the command to goto the coordinates displayed by the image, "View Telescope Direction" = query the telescope where it is looking to and center the image around these coordinates. The Nexstar interface is not jet tested very good because i am still waiting for some hardware parts to complete the system.

To specify the location where the user is using the Zaurus Sky Explorer use the "edit location" menu. This will open a dialog where a location can be selected or created.

To save all specified settings use the save settings menu item, these settings will be used the next start of the Zaurus Sky Explorer.

I(information) menu

All currently loaded catalog information is displayed in the Information menu. For example the number so stars currently in memory is displayed here (it will change depending on the field of View and central coordinates).