# N i g h t V i s i o n

Version 4.0
Copyright (C) B. Simpson 2015
Astronomy program for your computer

Night Vision is a "planetarium" program for computers, and will display the heavens from any location on earth. Viewing options allow the user to control which sky objects to display, which font to use, and manipulation of various star parameters. Time may be set to run at multiple speeds, including backwards. Color star charts may be printed.

Because this program is written in Java, it can run on any computer with a recent version of Java installed (includes most computers - see requirements below).

## Night Vision on the Internet

Night Vision has a home page on the Internet at:

        http://www.nvastro.com/nvj.html

Currently you can contact the author at:

        bsimpson@nvastro.com

It is a good idea to prefix your Email subject line with [NV], as in

        Subject: [NV] Like your program!

so that it is easily distinguishable from SPAM and is less likely to get inadvertently deleted.

## License

Night Vision is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

Night Vision is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

This license is included here and is also available at http://www.gnu.org/licenses/gpl-3.0-standalone.html.

## Requirements

Night Vision should run on any computer that contains a recent Java Runtime Environment (Java 1.4 or later). Most computers sold in recent years meet this requirement. (In the unlikely event that yours does not, the Java software can be downloaded online.)

## Starting Night Vision

If Night Vision is installed by downloading and executing a self-installing package (i.e. clicking on an install link from a web page), an icon should be installed on your computer which, depending on the operating system and install options, is typically accessible through the start menu. Clicking on this icon will start the program.

Otherwise if Night Vision is installed by downloading the manual zip file, extract the files into a directory on your hard drive and issue the following command from a command window in that directory:

        java -jar nvj.jar

Java is case sensitive, so type the command exactly as shown.

On some systems (e.g. Windows) users can double click the left mouse button on the nvj.jar file icon to start the program.

## Your first view

Night Vision opens (when in the default Alt-Az mode) with a view of the heavens looking straight up (the zenith) from the user's preferred location. (Or, until a preferred location has been selected, a default location of Niwot, Colorado, a small town where this program started.)

Within the main star window the mouse can be used to manipulate the view. Simply click and hold the left mouse button, then drag it where desired. (Tip: It is best to click on the bottom half of the window when at the zenith to avoid a rapid change in azimuth.) To zoom in or out use the mouse wheel. Objects can be identified by clicking with the right mouse button.

Four Scrollbars can be added if desired by clicking "Set" on the menubar, then "Window..." to bring up the "Window preferences" window. The scrollbars can be used to control the azimuth and altitude (or right ascension and declination if in RA-Dec mode), the zoom, and rotation around the center of the window.

Additionally the view can be manipulated via the keyboard, e.g. pressing 'z' to zoom in, or 'Shift-z' to zoom out. See "Keys help" in the online help for further details.

Zooming in can also be accomplished by drawing a rectangle on the screen. This is done by holding down the 'Shift' key, then pressing the left mouse button and dragging the mouse. When the button is released the center of the rectangle is moved to the center of the window at a zoom level based on the area of the rectangle. (Press 'p' to return to the previous view.)

An entire 180° view can be seen (i.e. 90° in all directions from the center of the window) by zooming out and/or enlarging the window.

The toolbar allows for easy manipulation of viewable items and other program functions. Hovering the mouse over each button will trigger a popup that provides a brief description of its function.

Star charts may be printed by clicking on the toolbar's print button (or via the "File" pull down menu).

## Setup

Night Vision can be set up for any location on earth. Begin by going to the "Set location" window (via the "Set" pull down menu). Select the location closest to your location and press "OK Location". Or enter your longitude, latitude, and time zone values and press "OK Coordinates". If your new location is in a different time zone, then your local time (as displayed in the information bar above the star window) will have changed, and you must reset the time. To do so, go to the "Set local date/time" window (via the "Time" pull down menu), and then press "Set to computer date/time". You are now re-sync'd to your computer time.

Be sure to save this location information if you would like Night Vision to always start at this position. Go to the "File" pull down menu and select "Save location".

You may also save your viewing preferences (objects, fonts, colors, star parameters, ...) by selecting "Save preferences" from the "File" pull down menu.

Note: The location database used in the "Set location" window may be edited to add new locations. See "User editable files" in the online help.

## Translating Night Vision

Night Vision has been designed to be readily translable into other languages. See the online help for information.

## Misc. notes

The star database is derived from the "SKYMAP SKY2000 Master Catalog, Version 2". It contains over 140,000 stars (through 9th magnitude).

Various sources were used for the algorithms employed by Night Vision. Among them are Practical Astronomy with your Calculator (3rd edition) by Peter Duffett-Smith, and Astronomical Algorithms (2nd edition) by Jean Meeus.

## Future updates

Night Vision may be updated in the future. Future updates may include:

- Telescope interface
- User modifiable information bar
- Comets
- ...

## History

4.0 | Added view manipulation via mouse drag and mouse wheel. Larger and continuously variable star sizes. Find stars via their designation. Find deep sky objects via their category and name. Zoom-based limiting magnitude for stars and deep sky objects. Added deep sky name button to toolbar.
3.1 | Added "Apply" button to various windows. Using BitRock InstallBuilder to create Mac and Linux installable packages.
3.0 | Added a solar system window. Program now "open source" (with source code available) and licensed under GNU General Public License version 3. 3.0.1: Adjusted for Mac java issue.
2.2 | Increased number of stars to 9th magnitude. Angular size added for (most) deep sky objects. 2.2.1: Updated for new website and Email.
2.1 | Added RA-Dec mode. Enhanced the "Computer time" icon on the toolbar so that it indicates if the local time is out of sync with the computer's time.
2.0 | Added a toolbar, which facilitates program operation and adds new time change functionality.
1.3 | Added labels for grids. Enhanced accuracy and added angular size and distance for solar system objects. Added planet magnitude. 1.3.1: Fixed bug where "Select object" window did not show when running on Java 1.3. Also adjusted how time restarts when "thawed".
1.2 | Added precession and nutation. Expanded range of time to 1000AD - 3000AD. Added phases of the moon. Corrected a problem displaying the preview area in the "Set colors" window that occurs with some versions of Java. Added a web-based self-installing version for Windows users.
1.1 | Corrected "Star database file nvj.db is corrupted" problem on Mac OS X JVM 1.4.1_01. Mercury & Venus can now appear in front of sun.
1.0 | Initial Release