DBSP - The Double Spectrograph for the Palomar 200-inch Telescope

There is a new Blue Camera, and the operating system for both cameras is now an ArcVIEW graphical user interface. All VAX/VMS and FIGARO commands are obsolete. The "At_The_Telescope_Cookbook" section of the manual is most affected by this change. All the other sections are still valid especially the "Before_The_Run_Overview" which deals with the instrument basics. J. Hickey March 3, 2007

a two-channel (Red/Blue), low- to medium-resolution grating spectrograph

a) DBSP; b) Raw spectra...vertical slit images in telluric lines, with bright knots from HH objects; c) Raytrace of DBSP Red, click-on to enlarge


The Double Spectrograph is a low-to-medium resolution (R ~ 1,000 to 10,000) grating instrument for the Palomar 200-inch telescope Cassegrain focus that uses a dichroic (at, e.g., 5200 Å) to split light into separate red and blue channels ("sides"), observed simultaneously. In addition to 128"-long slits of various widths, a multislit mechanism permits the deployment of 8 separate 15" slit segments that may be moved spatially by +/- 26". The DBSP may optionally be configured with a rotating-waveplate polarimeter (either 1/2- or 1/4-wave plates), with which all Stokes parameters may be measured.

Click below to seek info or return to the Palomar homepage. The "DBSP Overview" describes the instrument, with some theory of operation, and presents some detailed information needed while planning a run (e.g., choice of dichroic and gratings; calculation of grating angles). The "DBSP Cookbook" describes, in a step-by-step fashion, how the instrument is operated during a run...particularly the requisite computer commands.

Download DBSP Log Sheet

DBSP Specifications

Needed Documentation

Before_the_Run Overview

Palomar Homepage

DBSP Experts

At_the_Telescope Cookbook

For further info please contact: P200 Instrument Support Last modified: 21 Dec 2014