This web page was originally written by Eric Bloemhof several years ago (~1998). Many of the references are obsolete in some fashion. However, the general overview of the instrument contained in these references can still be of use to first time observers. Both updated and obsolete documents can be found in the 200" control room. The on-line manuals are constantly updated and supported, so go there first.

Most of what you need to prepare a proposal and make your instrument setup choices is in "Before_the_Run Overview"

Most of what you need to operate the instrument step-by-step at the telescope is in "At_the_Telescope Cookbook"

For all questions concerning Palomar instrumentation please contact P200 Instrument Support Last modified: 23 Dec 2010

NOTE; That there is a new IRAF script grating calculator availble when you get to Palomar (written by Rick Burruss). This calculator is more accurate for the blue side camera given the chip size vs vignetting And obscuration. Please ask Jeff to show you the calculator when you get to Palomar.

The grating curves and catalog of comparison-lamp spectra found in reference 4) below, give a nice overview of the gratings and arc lamps available. However, the blue camera curves are obsolete due to the fact that the blue side camera has changed. The most useful resource is the on line NOAO Spectral Atlas . This atlas is very useful for identifying arc lines in DBSP images given the parameters from the on line calculator and/or the IRAF script grating calculator on the mountain.

1) J.B. Oke & J.E. Gunn 1982, PASP, vol. 94, p. 586 ... a journal paper describing the instrument shortly after it was built. Very good for mechanical and optical descriptions, which tend to remain current, but the CCD and computer control information is of course totally obsolete. Note that both cameras have been replaced.

2) "The Double Spectrograph", May 1997, by mph (Martha Haynes, at Cornell)... a concise (13-page), cookbook-style guide with particular attention to the details of computer control syntax (obsolete) and procedures for obtaining calibration spectra. This document can be found in the DBSP notebook in the 200" control room.

3) DBSP Spectropolarimeter Installation ... If you are using the spectropolarimeter, see the section on polarimetry in the before the run overview section of this on-line manual

4) 200-Inch Hale Telescope Cassegrain Spectrograph... 1995, an update by Robert Brucato of Section V of the Palomar Observatory Manual; the original is cited immediately below. A 1/4"-thick document, most of which is totally out of date but there is a somewhat useful inclusion called...
APPENDIX 5-B Atlas of arc lines for the Double Spectrograph, 1990, by Helen Johnston, Caltech (revised August 1991). This is a large collection of spectra taken on the internal "comparison" or (wavelength) calibration lamps. The spectra can be useful for a quick look reference, but the NOAO atlas is much more exact.
APPENDIX 5-A Grating Angle vs. Wavelength is useful for a general overview of what's available while choosing a grating, but you should use the Grating Angle Calculator in the on-line manuals to find the grating angle that will give a desired central wavelength (don't just interpolate on the hardcopy plots...the other scientists will mock your technophobia, and you'll miss a lot of other useful numbers coughed up by the calculator). The grating curves here contain a conceptual error in failing to distinguish red and blue sides for all gratings: the two sides have different angles between collimator and camera beams, and so must have different grating curves...this will give errors of order 500 A on the 1200 lines/mm gratings. Most of the rest of the information in this manual has been absorbed into the supported on-line documentation.

5) Operation Instructions for the 5-Meter Hale Telescope Double Spectrograph... original (1983) version of Section V of the Palomar Observatory Manual, J. B. Oke (revised 7/29/85). Dated by now but of historical interest. Totally superceded by the supported on-line documentation.


1) IRAF Manual. See the IRAF home page for complete IRAF documentation. A very few basic IRAF commands are included in the on-line DBSP Cookbook.

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