The Fabra-ROA Baker-Nunn Camera at Observatori Astronòmic del Montsec: a wide-field imaging facility for exoplanet transit detection
O. Fors, J. Núñez, J. L. Muiños, F. J. Montojo, R. Baena, M. Merino, R. Morcillo, V. Blanco
aa r X i v : . [ a s t r o - ph . E P ] D ec **FULL TITLE**ASP Conference Series, Vol. **VOLUME**, **YEAR OF PUBLICATION****NAMES OF EDITORS** The Fabra-ROA Baker-Nunn Camera at ObservatoriAstron`omic del Montsec: a wide-field imaging facility forexoplanet transit detection
O. Fors , , J. N´u˜nez , , J. L. Mui˜nos , F. J. Montojo , R. Baena , M.Merino , , R. Morcillo and V. Blanco Abstract.
A number of Baker-Nunn Camera (BNC) were manufactured by Smithso-nian Institution during the 60s as optical tracking systems for artificial satelliteswith optimal optical and mechanical specifications. One of them was installedat the Real Instituto y Observatorio de la Armada (ROA).We have conducted a profound refurbishment project of the telescope tobe installed at Observatori Astron`omic del Montsec (OAdM) (Fors 2009). Asa result, the BNC offers the largest combination of a huge FOV (4.4 ◦ x4.4 ◦ ) andaperture (leading to a limiting magnitude of V ∼ Refurbishment project
The BNC was designed as a f/1 0.5m photographic wide field (5 ◦ x30 ◦ ) telescopewith a spot size smaller than 20 µ m throughout the FOV.Among some others, the BNC has been refurbished following these phases:mechanical modification of the mount into equatorial and motorization of thetwo axes, optical refiguring of the originally photographic curved FOV to enablethe use of a 4kx4k 9- µ m custom-designed FLI ProLine CCD camera (see Fig. 1)and to comply the Baker’s original design spot size diagram, manufacture of atip-tilt adjustable spider vanes assembly and athermal CCD focus system (seeFig. 2), mirror realuminization and outermost 50cm lens repolishing to increasethe throughput of the system, construction of a reinforced glass-fiber enclosurewith sliding roof which will host the BNC at OAdM (see Fig. 3), development ofan XML-based messaging protocol and Java GUIs software, named Instrument-Neutral Distributed Interface (INDI), to control every device of the observatoryand schedule its operation both in remote and robotic modes (Downey 2009).On 23 Sep 2008, the BNC successfully saw first technical light at ROAtesting site (see Fig. 4). Note this image was still taken with unpolished 50cmlens and non-realuminizated mirror. The definitive commissioning at OAdM isexpected by early spring 2010. Observatori Fabra, Reial Acad`emia de Ci`encies i Arts de Barcelona, E-08002 Barcelona, Spain Departament d’Astronomia i Meteorologia and Institut de Ci`encies del Cosmos (ICC), Univer-sitat de Barcelona (UB/IEEC), E-08028 Barcelona, Spain Real Instituto y Observatorio de la Armada, E-11110 San Fernando, Spain Fors et al.
Figure 1. Custom-designedFLI CCD with field flattener. Figure 2. Spider vanes assem-bly and focus system for the CCD.Figure 3. Reinforced glass-fiberenclosure at OAdM. Figure 4. First technical lightof M31 at ROA on 23 Sep 2008.
Transit exoplanet detection
The robotic nature of the BNC, its huge FOV and its considerable aperture,enables the telescope to succesfully detect transits of exoplanets. This expec-tation is supported by the fact that the Automatic Patrol Telescope (APT),originally a BNC twin of ours and, which after a similar refurfishment (al-though with an smaller FOV and less sensitive CCD), has succesfully compiledthe UNSW Extrasolar Planet Search 2004-2007 catalogue of exoplanets candi-dates (Christiansen et al. 2008). This catalogue shows that BNC-based camerascan accomplish millimagnitude photometry at least up to V ∼
14 magnitude.
Acknowledgments.
This work was supported by the Ministerio de Cienciae Innovaci´on of Spain and by Departament d’Universitats, Recerca i Societat dela Informaci´o of the Catalan Goverment.