The HPOL Spectropolarimeter

The HPOL spectropolarimeter is a modified Boller and Chivens small telescope spectrograph. The system provides simultaneous spectrophotometry and spectropolarimetry over the range of 3200A to 10500A (prior to 1995, the spectral range was 3200A to 7750A), with a spectral resolution of 10A (25A prior to 1995). The halfwave plate is a super-achromatic half-wave retarder. The wave plate is rotated by a stepper motor and rack and pinion drive, with stops every 11.25 degrees. A Wollaston prism produces two orthogonally polarized beams (ordinary and extraordinary) separated perpendicular to the dispersion. The ultraviolet achromatic camera is specifically designed for this instrument. The camera is all-refractive, which eliminates vignetting and thus enhances the polarimetric stability. The image is focused on a 400 X 1200 pixel CCD. Through 2004, the instrument was primarily installed as a dedicated intrument 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. HPOL has been down since October 2004 due to hardware problems.

HPOL no longer resides on the 36" telescope at Pine Bluff Observatory. An effort is being made to refurbish and relocate HPOL to Ritter Observatory, a 1-meter telescope at the University of Toledo run by the Ritter Astrophysical Research Center. This project is being led by Dr. Karen Bjorkman (University of Toledo), Dr. Jennifer Hoffman (University of Denver) and James Davidson (University of Toledo).

HPOL has been in operation at the University of Toledo's Ritter Observatory, with 'first' light on March 11th, 2012. Observations for testing and calibration purposes have been the focus up to this point. HPOL is currently operational in 'medium mode'. Examination of calibration observations at Ritter are comparable to PBO. 'faint mode' operations are planned to be up and running in the future. Normal hit-list observing will begin soon.

Fits files and ASCII files for HPOL data taken from February 1989 through July 14, 1998 can be obtained from the Mikulski Archive for Space Telescopes (MAST) .
July 16, 1998 - October 10, 2004 data will be delivered to the MAST and archived in the future.

HPOL Programs

The HPOL target database was last updated Feb 21, 2013.

Poster presented at the 2011 STARPOL meeting:
HPOL: World's Largest Database of Optical Spectropolarimetry

This plot shows all HPOL observations in galactic longitude and latitude.

Primary contact people

• HPOL contact: Dr. Karen Bjorkman
• HPOL scientist: Dr. Jennifer Hoffman
• HPOL creator: Dr. Kenneth H. Nordsieck
• Data manager: Brian L. Babler
• Data manager: Marilyn R. Meade

UW Space Astronomy Laboratory
Sterling Hall
475 N. Charter St.
Madison, WI 53706
Telephone: 608-263-4680, Fax: 608-263-0361.

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