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France's Haute-Provence Observatory


The Observatoire de Haute-Provence (OHP) was created in 1937 as a national facility for French astronomers although the first plans for a privately financed observatory date from as early as 1923. The first astronomical observations were made in 1943 with the 1.20m telescope and the first research paper dates from 1944. The facilities were made available for foreign visiting astronomers in 1949. The Observatory is owned by the Centre National de la Recherche Scientifique (CNRS) and is funded by the CNRS and the Institut National des Sciences de l'Univers (INSU). OHP is part the Marseille-Provence Astronomical Observatory (OAMP) federation.

OHP is situated in southeast France on a plateau at 650m altitude, near the village of St. Michel l'Observatoire, Alpes de Haute-Provence (southern French pre-Alps) at +44° latitude and 5.7° East longitude. It is located 90 km East of Avignon and 100 km North of Marseille and the nearest towns are Forcalquier (12 km) and Manosque (17 km). A schematic road map shows the main highways leading to OHP.

St.Michel l'Observatoire with OHP in the background

On the average, astronomical observations are possible 60% of the time (best seasons are Summer and Autumn). The yearly breakdown (based on 20 years of statistics) is : 170 nights are rated as excellent, 50 nights with occasional cloud and 70 nights partly cloudy. Image quality is usually around 2 arc-sec but can reach 1 arc-sec at times. Seeing degrades severely when the Mistral cold wind blows from the northwest (on the average 45 days/year, mostly in winter). However, Mistral winds usually clear up the sky and subsequent good weather spells follow. On the average, extinction at OHP is roughly twice that for ESO at La Silla.

Telescopes, Instrumentation and Detectors


This telescope, built by Grubb-Parsons and operating since 1958, originally had Newton, Cassegrain (f/15) and Coudé (f/30) foci. Only the Cassegrain focus currently exists. Available instruments are : a long-slit Cassegrain spectrograph (Carelec) with all-reflecting optics (dispersions of 260, 130, 33 and 17 Å/mm) and a new high-resolution (40000 and 75000), cross-dispersed échelle spectrograph (Sophie) in the first floor which is fed by a fiber-optic bundle from the Cassegrain focus. Offset auto-guiding is available for both spectrographs. All instruments are computer-controlled and use thin, back-illuminated CCD chips : an EEV 42-20 CCD (2048x1024) for Carelec and a EEV 4096x2048 for Sophie. On-line image display and pre-processing are available for Carelec using MIDAS software from ESO. Sophie has its own pipeline reduction from Geneva Observatory, derived from HARPS software. The telescope attitude is digitized, the coordinates are remotely displayed and a detailed pointing model exists, allowing accurate setting. New motors have been installed in both axes, on the secondary and on the dome to allow for direct computer control.

1.52 m

Built by REOSC, and operating since 1967, this telescope has only a Coudé focus. It is almost a twin of the 1.52m ESO telescope at La Silla (which in addition has a Cassegrain focus). Currently available is a high-resolution spectrograph (Aurélie). It features a 3" entrance aperture, an efficient Bowen-Walvaren image slicer, has resolutions from 34000 to 120000 and utilizes a thin back-illuminated EEV 42-20 CCD (2048x1024). The spectrograph is computer-controlled and pre-processing with MIDAS is available. The telescope and building were recently modified to accomodate a polychromatic laser star demonstrator (EL-POA).

1.20 m

This telescope, the first installed at St. Michel, operates since 1943. It only has a Newton focus (f/6) with two available ports. It is now used with a CCD camera system for direct imaging and photometry using UBVRI filters. A thinned back-illuminated AR-coated SITe 1024x1024 CCD chip was installed in January 1996. A remotely controlled auto-guider system allows long exposures to be made. Image display and reduction facilities using MIDAS are available.

0.80 m

This is the oldest telescope in use at OHP. It was first used at Forcalquier for site testing in 1932 and was later moved to St. Michel in 1945. The first foreign visiting astronomers ever to come to St. Michel used it in the summer of 1949 (Mr. and Mrs. Burbidge, to be exact). It features Newtonian and Cassegrain (f/15) foci. It now accommodates visitor or student equipment for special needs.

Other, specialized telescopes are also located at OHP but are not regularly used : a 60/90cm Schmidt telescope for wide-field direct imaging with plates or film, a 1-m telescope, owned by Geneva Observatory, with the historic Coravel radial-velocity spectrometer, and a 50-cm telescope belonging to the CNES French Space Agency which was used for satellite surveillance. Night assistants are few in number and are assigned to the 193cm telescope, but may be exceptionally available at the 152 and 120cm telescopes.


Two geophysical research stations are located on the observatory grounds. The Sun-Earth relations group study the mesosphere and thermosphere. The LIDAR group uses lasers to sound the troposphere and stratosphere and study, among other subjects, aerosol and ozone content.

Observing Time Requests and Financial Support

Observing time is scheduled on the semester system (March-August, September-February) with deadlines around Oct. 15 and April 15. Observing Time requests for the 1.93-m telescope should now be submitted throught the NORTHstar proposal system. Proposals for the other telescopes are to be submitted directly to OHP. Several national selection committees (PNPS, PNG, PNP, PMCI) rate proposals on scientific merit but the scheduling is done locally. Full financial support for travel and accommodation expenses is available for all French visiting astronomers through the selection committees. Foreign visitors can apply for observing time through the OPTICON Access program, funded by the European Union.

As of 1 August 1999, observing time at OHP is charged to all observers on a fee basis (not including VAT) of 280 Euros/night for the 1.93m, 230 Euros/night for the 1.52m, 120 Euros/night for the 1.20m and 60 Euros/night for the 0.80m telescope. Guest-house room and board charges are to be found in the Maison Jean-Perrin webpage. Foreign observers whose proposals are approved through the OPTICON Access program will have all their expenses paid by the program.

General Facilities

Workstations are used at the 1.93, 1.52 and 1.20m telescopes for data acquisition, instrument control and on-line pre-processing of data coming from the Sophie, Aurelie and Carelec spectrographs and the 1.20m direct imaging CCD camera. Off-line PC/Linux stations are available at the 1.93, 1.52 and 1.20-m domes for general use with the basic software tools, including the MIDAS and IRAF packages. The observatory has a optical fiber Ethernet network linking the main buildings and domes and is connected to the Internet by a dedicated 34 Mbit/s link through the regional high-speed network.

The observatory owns a complete astronomical library. There are also engineering, software, mechanical, optical and electronics laboratories equipped with modern workstations for mechanical, electronic and optical design as well as instrument tests and software development. Astronomical instruments are designed, built and serviced at the Observatory. A recently-built hall is available for the integration of large instruments.

A Guest House (Maison Jean Perrin) offers room and board facilities to visiting astronomers during their observing runs. A small resident staff carry out their own research programs and help in introducing visitors to the available facilities. The entire Observatory staff, including research, technical, administrative and Guest House personnel is about 60.

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Dernière mise à jour : 30 Nov 2017