CIRPASS test observations - 15th Jan 2002

This was the first night the 8-inch Celestron (affectionately dubbed the "Jiminy Telescope" due to its small size) was operated on the night sky. The weather was good most of the night but we had problems with background light from a high-intensity IR flood light (for the security camera system) and dew forming on the front of the telescope. We successfully demonstrated that we could acquire and track objects and beam-switch them on the IFU. A key part of this process is the software to generate an IFU image from the spectral data. This worked beautifully and images of how the light was falling on the IfU were displayed within seconds of the data being taken.

Data obtained

Initially relatively bright objects were used for aligning the telescope with the instrument: an image of Jupiter on the IFU is shown below

Exposures were taken of the same star at various positions on the IFU, allowing us to "beam switch" the data. A beam switch of two 30 second exposures on Pollux is shown below:

 The following spectrum is a combination of six of these 30 second exposures on Pollux

 Similarly for Arcturus:

 And for Jupiter. The strong absorption longward of 16200A is due to methane.


Andrew J Dean <ajd@ast.cam.ac.uk>
Ian Parry  <irp@ast.cam.ac.uk>

Last modified: Wed Jan 23 15:13:55 2002