The High Speed Photometer (HSP) is a

scientific instrument A scientific instrument is a device or tool used for scientific purposes, including the study of both natural phenomena and theoretical research. History Historically, the definition of a scientific instrument has varied, based on usage, laws, a ...

formerly installed on the

Hubble Space Telescope The Hubble Space Telescope (often referred to as HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most ver ...

. The HSP was designed to measure the brightness and polarity of rapidly varying celestial objects. It could observe in

ultraviolet Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30 PHz) to 400 nm (750 THz), shorter than that of visible light, but longer than X-rays. UV radiati ...

visible light Light or visible light is electromagnetic radiation that can be perceived by the human eye. Visible light is usually defined as having wavelengths in the range of 400–700 nanometres (nm), corresponding to frequencies of 750–420 tera ...

, and near

infrared Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from aroun ...

at a rate of one measurement per 10

microseconds A microsecond is a unit of time in the International System of Units (SI) equal to one millionth (0.000001 or 10−6 or ) of a second. Its symbol is μs, sometimes simplified to us when Unicode is not available. A microsecond is equal to 100 ...

. The design was novel in that despite being able to view through a variety of filters and apertures, it had no moving parts "except for electrons" as principal investigator Prof. Robert Bless was fond of saying. Filter and aperture selection was accomplished using image dissector tubes and the HST pointing system. It was functional from launch in 1990 until it was removed at the end of 1993, and it helped diagnose an issue with the Hubble's primary mirror. The HSP was one of the instruments on Hubble at launch. Its primary mission was compromised by the optical problems with the telescope, although some projects were still successful. During the first servicing mission, in December 1993, it was replaced by the Corrective Optics Space Telescope Axial Replacement (COSTAR), which corrected the optical problem for the remaining instruments. The principal investigator for the instrument was Dr. Robert C. Bless. Dr. Bless died in 2015, and his contributions to the Hubble Space Telescope and the HSP instrument were noted in news media. He worked at the

University of Wisconsin–Madison A university () is an institution of higher (or tertiary) education and research which awards academic degrees in several academic disciplines. ''University'' is derived from the Latin phrase ''universitas magistrorum et scholarium'', which ...

, and the HSP was the lightest and least expensive of the launch instruments. The HSP instrument is located as of 2015 at the University of Wisconsin-Madison's

Space Place Space is the boundless three-dimensional extent in which objects and events have relative position and direction. In classical physics, physical space is often conceived in three linear dimensions, although modern physicists usually consider ...

. It was scientifically active during its period of use, an example of observations taken with the instrument is ultraviolet photometry of Nova Cygni 1992.''Ultraviolet Photometry of Nova Cygni 1992 Obtained with the High Speed Photometer'' 1994
/ref>

Purpose, objectives

Specifications

* Wavelengths of light detected 115 nm to 870 nm * Mass : 300 kg or 273 kg * Fields of view 0.4, 1.0, and 10.8 arc-seconds''High-Speed Photometer (HSP)''
/ref> (arc-seconds are unit of

degree Degree may refer to: As a unit of measurement * Degree (angle), a unit of angle measurement ** Degree of geographical latitude ** Degree of geographical longitude * Degree symbol (°), a notation used in science, engineering, and mathemati ...

)

History

Operations

Results

Notes

External links

HSP Information at STSCI

HSP Instrument Handbook v3
blank figures
HSP at the University of Wisconsin's Space Astronomy Laboratory
{{Hubble Space Telescope Hubble Space Telescope instruments Space science experiments Space hardware returned to Earth intact