There are two spectrographs on the Rigel telescope. The FFS (fiber-fed spectrometer) and TGS (transmission grating spectrometer. Both were installed in April 2011 and are being tested during May - June for routing use starting September 2011.
FFS. The fiber-fed spectrometer consists of a commercial Ocean Optics Maya 2000 spectrometer, with 2048 channels, 65% peak QE, H2 grating (600 lines per mm blazed grating), a 50 micron slit, and a spectral range of 350 nm - 800 nm. The spectrometer has a resolution of 1 nm and uses the Ocean Optics Spectrasuite software.
TGS. The transmission grating spectrometer (TGS) is a 600 line per mm, 50 mm2 square transmission grating installed in the filter wheel (filter code T). The data reduction software, TGS-spec, was written in Python and will be made available after completion, probably September 2011.
The TGS resolution varies with wavelength, from 2.5 nm at 350 nm to nearly 10 nm at 750 nm. A plot of the resolution as a function of wavelength is shown at right. Note that the resolution can be improved at longer wavelengths by titling the grating 5o, which we have not yet done
Update May 13, 2011
WR 137
We are continuing to tweak the transmission grating spectrometer (TGS) that was installed in late April. In the sidebar are four spectra observed May 11 and calibrated using the very nice commercial program Rspec [http://www.rspec-astro.com], which does both polynomial wavelength-to-pixel calibration and amplitude normalization using a library of standard calibrated spectra. The spectra are not amplitude calibrated yet, but are wavelength calibrated.
The TGS doesn't have high spectral resolution (about 2 nm at best), but it is sufficient for many projects, as these spectra demonstrate. It is also ideal for robotic systems, since it is unnecessary to manually set a star on a narrow slit. We have ordered a new filter wheel, dispersion gratings, and slits to enhance the TGS.
A gallery of TGS spectra is available here. Some recent spectra include:
WR137, WR140. Two very luminous, very hot Wolf-Rayet stars with optically thick winds. The emission lines, mostly H, He, C, and O in excited states, arise from the winds. These are rare, short-lived stars well on the way to becoming Type II supernovae.
T Pyxidis. A recurrent nova whose last outburst was in 1966. In April 2011 it brightened from 14 to 7 (600x luminosity). This is a binary consisting of a main-sequence star and a white dwarf - the MS star accretes gas onto the WD, which undergoes sudden fusion reaction near the surface when the accreted mass reaches a critical level. The enormously bright H alpha line is from hydrogen in the expelled gas.
delta Scorpii - A B0 subgiant with a prominent H emission lines.