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Mission Overview

Map of Observations

HPOL observations

Wavelength Coverage

HPOL wavelength coverage plot

The Halfwave spectropolarimeter (HPOL) is a modified Boller and Chivens small telescope spectrograph. The system provides simultaneous spectrophotometry and spectropolarimetry over the range of 3200Å to 10500Å (prior to 1995, the spectral range was 3200Å to 7750Å), with a spectral resolution of 10Å (25Å prior to 1995). For more information about the instrument see the "About HPOL" page. The instrument is installed on one of three telescopes. Through 2004 it was installed as a dedicated instrument to the 36" telescope at the University of Wisconsin-Madison Pine Bluff Observatory (PBO). HPOL was also mounted on the 3.5 m WIYN telescope at Kitt Peak National Observatory for limited observational runs once a year or so. In 2012 it was moved to the Ritter Observatory at the University of Toledo. Only data through 2004 is currently archived at MAST. MAST archives HPOL data as a complement to the data obtained by the WUPPE instrument flown on the Space Shuttle as part of the ASTRO project that is also archived at MAST.

Active From

February 1993 - October 2004


R ~125 - 1050 (depending on wavelength and date)


  • Spectropolarimetry
  • Spectrophotometry


Search Tools

Featured Data Products

Extracted Spectral Files: Calibrated FITS files with spectrophotometry and spectropolarimetry for each object.

ASCII Spectral Files: ASCII text table versions of the spectropolarimetry files.

Supplemental Links

HPOL Images


HPOL Coverage Plot
HPOL Coverage Plot
HPOL Observations
HPOL Observations