High Accuracy Radial velocity Planet Searcher

High Accuracy Radial velocity Planet Searcher
Name	High Accuracy Radial velocity Planet Searcher
Organization	European Southern Observatory
Location	La Silla Observatory
Altitude	2400 m
Established	2003
Telescope type	Echelle spectrograph

Contents

High Accuracy Radial velocity Planet Searcher is a fiber-fed, cross-dispersed echelle spectrograph installed at the La Silla Observatory and operated by the European Southern Observatory. It was developed to measure sub-meter-per-second radial velocities for exoplanet detection and characterization, influencing work at facilities linked to the Very Large Telescope, Cerro Paranal Observatory, and collaborations involving institutions such as the Observatoire de Genève and the Max Planck Institute for Astronomy. The instrument’s precision and long-term stability have been pivotal in follow-up campaigns associated with surveys by teams from the California Institute of Technology, Harvard–Smithsonian Center for Astrophysics, and the Space Telescope Science Institute.

Overview and History

The project emerged from proposals by researchers at the Observatoire de Genève, Université de Genève, and the European Southern Observatory to achieve radial-velocity precision beyond that of predecessors at facilities like the Lick Observatory and the Keck Observatory. Construction and commissioning involved engineers and astronomers affiliated with the Max Planck Society, the University of Geneva, and instrument groups with links to the Institut d'Astrophysique de Paris and the University of Porto. Early operational milestones coincided with notable exoplanet announcements from teams including the California Planet Survey and observers associated with the Anglo-Australian Observatory. The instrument entered routine operations in the early 2000s and contributed to long-baseline programs coordinated with observatories such as Mount Wilson Observatory and the Palomar Observatory.

The spectrograph is a thermally stabilized, vacuum-enclosed, fiber-fed echelle instrument built with optical designs informed by groups at the European Southern Observatory, the Observatoire de Genève, and the Laboratoire d'Astrophysique de Marseille. Its optical train includes an R4 echelle grating, a cross-disperser, and a pupil slicer developed in collaboration with engineering teams from the Max Planck Institute for Astronomy and the University of Bern. Wavelength calibration strategies were derived from work at the National Institute of Standards and Technology and incorporate simultaneous reference techniques inspired by projects at the Royal Observatory Edinburgh and the National Astronomical Observatory of Japan. The detector system uses a high-stability charge-coupled device whose controllers were produced in cooperation with groups at the European Southern Observatory and the Astrophysics Research Institute.

Operations are coordinated through the La Silla Observatory scheduling office and integrate queue and visitor modes similar to protocols at the Very Large Telescope and the Cerro Tololo Inter-American Observatory. Observing programs range from long-term radial-velocity monitoring by teams at the Observatoire de Genève and the Max Planck Institute for Astronomy to rapid-response follow-up for transit surveys conducted by collaborations including SuperWASP, Kepler, K2, and TESS. Modes include simultaneous-reference calibration, sky-fiber subtraction developed parallel to techniques at the Anglo-Australian Observatory, and bright-target optimized exposures used by investigators from the California Institute of Technology and the Harvard–Smithsonian Center for Astrophysics.

Data pipelines incorporate algorithms and software developed with contributions from the Observatoire de Genève, the Max Planck Institute for Astronomy, and the European Southern Observatory. Techniques include cross-correlation function analysis established by groups at the Institut d'Astrophysique de Paris, barycentric correction standards following conventions from the International Astronomical Union, and instrumental profile modeling informed by calibration efforts at the National Institute of Standards and Technology. Advanced post-processing has been influenced by statistical methods used by teams at the University of Cambridge, the Princeton University, and the University of California, Berkeley to disentangle stellar activity signals studied by researchers at the Harvard–Smithsonian Center for Astrophysics and the Institute of Astronomy, Cambridge.

The instrument contributed to the confirmation and mass measurement of numerous exoplanets found by survey teams such as SuperWASP, HATNet, Kepler, and TESS, and supported characterization studies published by researchers affiliated with the Observatoire de Genève, the Max Planck Institute for Astronomy, and the Harvard–Smithsonian Center for Astrophysics. It enabled precision mass determinations for small planets in systems also observed by the Spitzer Space Telescope and the Hubble Space Telescope, and provided long-term datasets used in comparative planetology studies alongside work from the California Institute of Technology and the Space Telescope Science Institute. The instrument’s legacy includes contributions to topics explored at conferences organized by the American Astronomical Society and the European Astronomical Society.

Planned and executed upgrades involved partnerships with the European Southern Observatory, the Observatoire de Genève, and technical groups from the Max Planck Institute for Astronomy and the Universidade do Porto. Successor instruments and parallel projects at institutions such as the Harvard–Smithsonian Center for Astrophysics, the Carnegie Institution for Science, and the Swiss National Science Foundation include next-generation spectrographs designed for meter-per-second and sub-meter-per-second stability, influenced by lessons learned from this instrument’s operations. Collaborative networks span the European Southern Observatory, the Observatoire de Genève, the Max Planck Society, and survey teams like SuperWASP, HATNet, and TESS mission scientists, maintaining the instrument’s role in coordinated exoplanet discovery and follow-up programs.

Category:Spectrographs Category:Exoplanet search projects Category:European Southern Observatory instruments