A SURVEY PROGRAM

The ability to automatically aim a telescope with a computer considerably increases the productivity of an astronomical installation. With the human factor removed, it is possible to perform operations that are extremely boring to do manually. These days, LX200 telescopes are a good example of instruments that could be used for automated observations. On the software side several solutions exist. The AUDACE software is specially adapted to read the Audine camera and command an LX200 at the same time.

In the following examples, our goal is much less ambitious as far as telescope piloting is concerned, but its realisation is possible for practically everyone. It involves replacing the hand paddle of the telescope by a software paddle. This replacement will be recognised by those who use auto guiding on their telescopes. In this case the mount is an NJP-160 (compatible with the EM-200 at the command level) on which a 190 mm F/D=4 flat-field camera is mounted. The pointing is handled by the PISCO software through a very simple interface (based on a serial port of the PC). The goal is to command the paddle by "pushing the buttons electronically" and in this way realizing images in adjacent fields. It is also possible to go back to a previous field by pushing the opposite pushbutton. In this manner it is possible to periodically record adjacent fields which is ideal for survey programs where we want to find asteroids by their movement or variable stars by their changing brightness.

Example of a strip of sky explored in automatic mode with an Audine camera and the Pisco software. These two joined images cover a 4° long strip across the sky. For each position the system made 5 exposures of 2 minutes, before going on to the next field and so forth. To do this we used the Survey acquisition mode of the Pisco software. The vertical displacement between the fields is caused by an insufficiently accurate east-west alignment of the rows of the CCD.
Comparison of a part of a recorded field and an electronic star chart, in this case generated by the Megastar software. The comparison of many sweeps of the same part of the sky makes it possible to detect, for example, moving objects. Nowadays image-processing software automatizes this comparison.
The eye of the telescope. The KAF-0400 CCD is visible as a small rectangle at the bottom of the optical tube of the 190 mm telescope.