NOTE: this project is going to be renamed to Asterope

OpenCoeli [ce:li] is astronomical planetarium, skycharting and observation planning tool. Main goal is to create easily extendable replacement for XEphem. First stable version should be around 2011.

Motivation

Main reason for new program is better code. It allows more features, better stability and more enjoyable codding. OpenCoeli is written in Java and Groovy. OpenCoeli is using standard Java libraries: Spring IOC, Java Persistence API, JUnit, Apache Commons, Jide, Picollo. It also uses some astronomy specific libraries: Skyview, Healpix, Pixy2...

Data

Data (stars, galaxies) are represented in data model (POJO) and persisted with JPA to embedded SQL database. This approach allows great flexibility. For example star can be linked with multiple catalogs, magnitudes and observations, but it still unique in data storage.

Data model is designed around professional catalogs from Astronomical Data Center. It can support all available fields: for example star can have multiple magnitudes in various wavelengths with errors and references to publication.

SQL is combined with Healpix spatial index. So it is possible to query data like:

SELECT star WHERE (position in Lyra) AND (magnitude < 3.0) 
    AND (distance from M57 < 2 degrees)

Maps and images

OpenCoeli produces maps in printable quality. It is inspired by PP3, but goes farer. For example label overlapping problem is solved by AI algorithm. Objects on map are represented in terms of layers, graphical nodes and events. So map is not static, but can be manipulated after creation.

Map generation is based on SkyView survey image generator. But it can be also used to generate background images for maps. Since it runs on your computer, you are not limited by online servers. DSS image 10000x10000 pixels in 30x30 degrees? No problem.

Pixy2 code is used to handle FITS images. It handles astrometry and photometry. It can also identify objects on image. And finally it can fine align image coordinates using stars.