Medium-Resolution Spectrograph

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• PI: Larry Ramsey, Penn State
• Fiber-coupled, located and bench-mounted in spectrograph room in HET "basement"
• Dual-beam echelle and white pupil design
• R = 5,000 to 20,000
• Initial visible beam has 450 to 900 nm wavelength coverage in one exposure
• Second beam will cover 900 to 1300 nm in one exposure with capability to 1800 nm
• 9 multi-object fiber probes
• Fiber "long slit" and single object fibers
• Optical fiber integrated field unit
• High wavelength stability
• 22% throughput on the sky
• Funded by in by NSF and Penn State
• Commissioning in 2001

Recent Reference:
Horner, S.D., Engel, L. and Ramsey, L.W., "The Hobby-Eberly Telescope Medium-Resolution Spectrograph and Fiber Instrument Feed," SPIE Conf. 3355, Kona, March 1998, p.375

For the latest information, including currently available instrument configurations, please refer to the relevant page of the HET Resident Astronomers' Web Site at this link.

You may also check out this PDF document by Larry Ramsey with the latest sensitivity information: Direct_Feed_Sept04.pdf

But note that the latest measurements of the transmission efficiency of the red and blue fibers (Figure 4 in this report) show that the transmission of the red fiber is higher than that of the blue fiber at all wavelengths longward of 4500 Å (i.e., the red fiber curve should be scaled upwards somewhat so that it matches that of the blue fiber at 4500 Å).