The Telescopi Joan Oró (TJO) is a 1m-class telescope working in a completely unattended manner. The construction of this robotic telescope motivated the development of the Observatori Astronòmic del Montsec (OAdM), a site devoted to host astronomical research facilities. This is the largest telescope in Catalonia (0.8-m), named Joan Oró after the famous Catalan biochemist and pioneer of astrobiology.

The TJO is operated since 2007 by the Institut d'Estudis Espacials de Catalunya (IEEC).


The TJO is a 0.8 m telescope supplied by Optical Mechanics Inc. (OMI), equiped with a fully automatic 6.15-m dome manufactured by Baader Planetarium GmbH, and a photometric imaging camera (MEIA) as first light instrumentation.

Several instruments for environment monitoring are acquiring data continuously: two weather stations, a GPS antenna, a storm detector, etc. A fiber-optics connection with 100 Mbps bandwidth provides external communication necessary for remote access.

A complex software architecture manages all observatory operations. This architecture is mainly managed with OpenROCS, an open-source software developed to control robotic observatories. Low-level telescope and dome control is conducted through the TALON software.

Operation mode

The needs of the scientific cases and the isolation of the site, made of ??robotic operations a hard requirement for nominal operations of the observatory. Observers just need to send the proposals with the sources of study and retrieve the acquired data and images. The telescope is being prepared to ensure high quality astronomical observations using this mode.

Scientific cases

The TJO is a general purpose facility and, as such, it carries out a variety of observations related to various science cases. Given its size, the main scientific niche for TJO is the time-domain astronomy, where high-cadence, continuous observations are the primordial requisite. Its main advantage is a flexible operation mode allowing for the monitoring of sources for extended time periods and also the possibility of a rapid reaction time, potentially as short as a minute or less. Given such features, the possible science cases for TJO include:

  • Exoplanet research (possibly follow-up of known transiting planets or targeted searches of individual objects).
  • Eclipsing binaries (to understand stellar properties and structure).
  • Pulsating variables (probing the stellar interior).
  • Evolved variable stars (giants and supergiants).
  • Stellar activity (to understand the magnetic dynamo and to calibrate the time-decay of such activity).
  • Variability of active galaxy nuclei (related to the stochastic accretion process).
  • Solar System objects (follow-up of asteroids, near-Earth objects, comets).
  • Supernovae (with the added value of obtaining early photometry).
  • X-ray binaries (rotational variability and accretion phenomena).
  • Novae (also with possible early data).
  • Optical counterparts of Gamma Ray Bursts (GRBs).
  • Any transient phenomena in general.

The science cases above require important flexibility in the night scheduling, which allow the system to react rapidly to observational alerts related to GRBs, new supernovae, and similar time-critical events. The participation in the networks of robotic observatories would enable to carry out, for example, observations requiring continuous time coverage. Similarly, the TJO can be used as a support facility for space missions to collect photometric and astrometric data. The TJO offers time to the astronomical community via competitive proposals peer-reviewed by an independent Time Allocation Committee (TAC).

Generalitat de CatalunyaUniversitat de BarcelonaUniversitat Autònoma de BarcelonaUniversitat Politècnica de CatalunyaConsejo Superior de Investigaciones CientíficasCentres de Recerca de Catalunya