revised 04/09/98

TAURUS is a wide-field imaging Fabry-Perot interferometer designed to obtain spectra over a field of up to 9 arcmin with a resolving power anywhere between 2,000 and 100,000. Its main use is in measuring velocity fields of extended emission line objects - HII regions, planetary nebulae, supernova remnants and galaxies.
A TAURUS spectral scan normally consists of a large number (typically 100) of separate 2-dimensional images taken sequentially at different gap settings of the Fabry-Perot etalon, each giving a two-dimensional image in a different wavelength bin. By stacking these together it is possible to build up a 3-dimensional spectral line datacube.


TAURUS has successfully been used with the ALPHA TCS. The focal setup must still, however, be typed in by hand AUTOGUIDER:
Autoguiding is done using the CASS autoguider. GSS for finding guidestars, ICL>prag x y for moving the guideprobe to the required position. (Remember to configure GSS as gss>con wht taurus)

Use Direct mode (AGCOMP) to acquire objects as slitviewing is not possible.


Telescope focus:
The best telescope focus is determined by taking short exposures on the CCD. Last focus value: 96.9mm (04/09/98)

Calibrate procedure:
The best (only) way to determine the rotator center and performing the calibrate procedure is by using the TV Direct Viewing mode (acquisition mirror in by typing ICL>AGCOMP). Proceed as usual. Last RotCen:263, 275 (scanswitches up,up 04/09/98))


You might have to offset the telescope to get the object to where the observers want it on the (windowed) CCD. Example: Offsets in RA +25arcs and +60 in DEC to get the object near the centre of a 300x300 window with xstart=365, ystart=556 (TEK2). Although you can enter an aperture offset to take this into account, it's probably better to offset 'by hand', as the actual telescope position is needed for finding guidestars in GSS.
Once on the object, you'll stay very long as a typical 3D cube consist of 55x60sec exposures.
*** Remember to remove the agmirror (AGMIRROR OUT) before starting the exposure ***


Observing logs:
Because no script has been developed yet to extract all the necessary TAURUS header information, you will need to create two logs per night: One for the archive (normal nightlog, from lplogs account), and one special TAURUS log for the observer. Better yet, this log has to be done by hand!.

A template log (taurus.log) is stored in the logdata directory. (A special TAURUS account also exists on lpss1). AT the end of the night, print the log using a2ps -1 -nd -F6 -nL -l <logfile> | lpr -Pwht_laser and store it together with the normal nightlog in the observinglogs folder.