JAST/T80 progress report

The Javalambre Auxiliary Survey Telescope (JAST/T80) is an 80cm Ritchey Chrétien telescope with a large field of view of 2 deg diameter, particularly defined for carrying out large sky photometric surveys like J-PLUS. Click here for a detailed technical description of the JAST/T80.
February
 
 

An image of the Pinwheel Galaxy (M101) taken at OAJ with JST/T80 telescope and the T80Cam camera. The image consists of a composition of 19 different images in the Sloan g, r and i filters and uJAVA, J0515 and J0660 filters, with a total integration of 156s in filter g, 250s in filter r, 78s in filter i, 621s in filter uJAVA, 123s in filter J0515 and 810s in filter J0660 and less than 1.2" of average PSF. The images were taken on 4th February 2016.

The Observatorio Astrofísico de Javalambre (OAJ) has announced its first call for proposals for observing with T80Cam, the scientific, panoramic camera installed at JAST/T80 telescope.

 
November
 
 

J-PLUS survey observations with T80Cam@JAST/T80 have started after an intense period of fine tuning and optimization tasks developed by the OAJ/CEFCA Team. J-PLUS is the main project to be carried out for the next three years with the T80Cam panoramic camera installed at the JAST/T80 telescope at OAJ.

An image of the Triangulum Galaxy (M33) taken at OAJ with JST/T80 telescope and the T80Cam camera. The image consists of a composition of 46 different images in the Sloan g, r and i filters and J0660 filter, with a total integration of 440s in filter g, 410s in filter r, 460s in filter i and 3840s in filter J0660 and less than 1" of average PSF. The images were taken on 11th, 14th and 15th November 2015.

 
March
 
 

An image of the Hercules Globular Cluster (M13) taken at OAJ with JST/T80 telescope and the T80Cam camera. The image consists of a composition of different images in the Sloan g and r filters and white light, with a total integration of 40 min and 1.7" of average PSF. The images were taken on 7th March 2015.

An image of the Bode's Galaxy (M81) taken at OAJ with JST/T80 telescope and the T80Cam camera. The image consists of a composition of different images in the Sloan g and r filters and white light, with a total integration of 50 min and 1.07" of average PSF. The images were taken on 6th March 2015.

An image of the Cigar Galaxy (M82) taken at OAJ with JST/T80 telescope and the T80Cam camera. The image consists of a composition of different images in the Sloan g and r filters and white light, with a total integration of 50 min and 1.07" of average PSF. The images were taken on 6th March 2015.

 
February
 
 

JAST/T80 telescope handover to CEFCA

In 2015, February 20th, after a complete process of verification and final acceptance tests, the handover of the JAST/T80 telescope by CEFCA has been made effective. The telescope is complete and operative according to the requirements, hosting already T80Cam, which is undergoing characterization, commissioning and fine tuning tests.

 
December
 
 

High resolution image taken by JAST/T80 telescope.

 
August
 
 

An image of the Dumbbell Nebula taken at OAJ with JAST/T80 telescope and the FLC80 verification camera. The image consists of a composition of different images in the Sloan g and r filters, with a total integration of 1 hour and 30 min and 1" of average PSF. The images were taken in July 2014.

 
July
 
 

An image of the moon taken at OAJ with JAST/T80 telescope and the FLC80 verification camera. The image consists of a composition of 200 different images with 0.04 s of exposition in the Sloan u filter, taken during the night between 13rd and 14th of June 2014.

An image of the M106 galaxy taken at OAJ with JAST/T80 telescope and the FLC80 verification camera. The image consists of a color composition of different images in the Sloan r, i and z filters, with a total integration of 30 min in every filter. The images were taken during the night between 6th and 7th of June 2014.

 
June
 
 

Development and implementation of active optic solutions for JAST/T80.

Once the field corrector of lenses and the verification camera FLC80 are installed at the telescope, the main tasks concentrate on implementing the procedure for the fine alignment and automatic focussing of the JAST/T80. Due to its large field of view, 2deg in diameter, the secondary mirror of the JAST/T80 is active by means of an hexapod that allows corrections in focus, decentering X-Y and tip/tilt X-Y, to guarantee the image quality of the telescope all over the field of view and at any position and temperature of the system. CEFCA has developed a specific software to correct in real time the image quality of the JAST/T80. The basis of the code is wavefront curvature sensing. It works as it follows. The telescope takes two consecutive defocused (intra/extra) images of a field of stars; the resulting donuts for each star are identified, and are decomposed as a function of a Zernike basis. With this information, and having calibrated previously the sensitivity of the hexapod movements in terms of these Zernike terms (the so called inversion matrix), the code computes the required hexapod corrections to be applied to M2 to obtain homogeneous and high quality images all over the focal plane. The attached figures illustrate two examples of the outputs of the code: a snapshot of the donut selection for a given defocused star in the field, and the wavefront solution for this configuration in the space of Zernike coefficients.

 
May
 
 

Field corrector installed at JAST/T80. After the mount acceptance and accurate alignment of M1 and M2, the three lenses field corrector of the telescope has been installed. The image shows the field corrector in the central hole of M1, just above the instrumentation anchorage level in the cassegrain focus.

 
April
 
 

FLC80 integration at JAST/T80.

 
March
 
 

Integration of the FLC80 filter wheel.

 
December
 
 

Design and manufacture of FLC80, the First Light Camera of JAST/T80. CEFCA has designed and has manufactured a First Light Camera, FLC80, for the commisioning and scientific verification of JAST/T80. The camera is a Proline 16803, with a Kodak KAF-16803 4096-by-4096 9?m pixel CCD detector, which provides a 34-by-34 arcmin field in the cassegrain focus of the telescope. The camera has a focuser (green) and a filter wheel with the capacity to 7 square filters of 50x50 mm (red). The entrance window above the detector has been replaced by a new one with optical power in one of its faces, designed by CEFCA in order to optimize the image quality in the entire JAST/T80 focal plane. Also, CEFCA has designed and has manufactured a Serrurier type mechanical support in order to anchor the FLC80 to the telescope. It includes the required counterweights in order to simulate the expected mass and center of gravity of the T80Cam. The image shows several views of FLC80, its anchorage serrurier structure and the counterweights (grey) together.

 
August
 
 

Integration of the mirrors onto the T80 structure at OAJ.

 
June
 
 

T80 optics acceptance after final mirror polishing and aluminization.

 
May
 
 

T80's arrival at OAJ and mechanical structure assembly works at the dome.

 
January
 
 

T80 during AIV phase. Main mechanical parts are fully assembled at ASTELCO’s headquarters.

 
December
 
 

The optical tube assembly, the Serrurier truss, the front ring, the 4 spider vanes and the M2 unit are assembled together.

 
November
 
 

The optical tube assembly and the Serrurier structure of the T80 are manufactrured in parallel for the T80-North (Observatorio Astrofísico de Javalambre) and T80-South (Cerro Tololo Interamerican Observatory).

 
October
 
 

The T80 mount and the main RA and DEC axes.

 
September
 
 

The field corrector of three spherical lenses of fused silica.

 
November
 
 

The M1 blank (Zerodur by SCHOTT; Germany) in polishing process at AMOS headquarters in Liege (Belgium).