35 cm Telescope


The T35 is a small telescope (14", 35cm) equipped with a large format CCD camera being a useful tool for detecting and studing variable stars, mainly in the environment of open clusters. Due to its characteristics, this telescope can also be used to the discovery and analysis of extarsolar planets as well as of minor bodys of the Solar System.



The instrumentation has been supported by the project Marie Curie Reintegration Grant MERG-CT-2004-513610 funded  under the European Commission's Sixth Framework and by the CoRoT project (ESP2004-03855-C03-01) of the Ministerio de Educación y Ciencia.

Telescope and detector characteristics

Type celestron CGE1400
Mount Ecuatorial alemana
Configuration Schmidt-Cassegrain
Aperture 14 in (35.56 cm)
f/# 11
Focal distance 3912 mm
Array SBIG STL-11000M
Sensor Kodak KAI-11000M
Pixel size 9 µm
Scale 0.248"/pixel
FoV 31.70' x 21.14'
Binning modes 1 x 1, 2 x 2, 3 x 3
Read-out time 26 sec (binning 1 x 1)
Gain 0.8 e¯/ADU
Read noise 11 e¯ rms
Dark current 1.5 e¯/pixel/sec (0° C)
Orientation North-Up, East-Lleft

The cooling system is standard using two-stage thermoelectric. Tthe CCD camera has additional cooling with circulating water in warm climates if need. Cooling to -50° C below ambient can be achieved with this system.

More detailed technical characteristics of the telescope and the CCD camera are in CGE1400 manual and SBIG STL11000M manual, respectivamente.


The camera has a internal filter carousel with five positions for 50 mm round filters. The available filter set is the Bessell (Johnson-Cousins) UBVRI system.


The telescope and the dome can be controlled locally from a conventional PC installed inside the dome. However, the control of the system in usual operation is performed from one of the user computers in the main building of the observatory. The telescope and CCD camera controls are carry out using commercial  softwares, TheSky Astronomy Software v6 and the MaxImDL v5. With MaxImDL, we can also focus the telescope with the digital focuser DF-2 Finger Lake Instruments. The Dome Control Software System is a  in-house developed software based ASCOM drivers allowing us to control the dome using the TheSky and MaxImDL.

Working team

This project has been able thanks to:

Francisco J. Aceituno, José Luis de la Rosa, Miguel Abril, Isabel Bustamante, Luis Costillo, Antonio García, José Luis Ramos y Tomás Pérez. And with the support of: José Luis Ortiz, Victor Costa, Rafael Garrido y Lourdes Verdes-Montenegro.

For more information, contact to F.J. Aceituno (fja [at] iaa.es) and Susana Martín-Ruiz (I.P. project) (susana [at] iaa.es).