When long term instrument stability is required, traditional alignment techniques based on bulky and/or flexible mountings can not be used due to their reduced stiffness. Mechanical alignment of optical systems is nowadays possible thanks to different 3D Coordinate Measuring Machines, as the Laser Tracker, the Articulated and Cartesian Arms. In this paper we describe the methods we considered for the integration and alignment of ESPRESSO, the very high resolution visible spectrograph for the ESO VLT, now under commissioning phase at Paranal Observatory. Different examples of the Front End (FE), the Anamorphic Pupil Slicer Unit (APSU), and the spectrograph itself will be provided, to demonstrate that it is possible to align an optical system with mechanical methods with minimal optical feedbacks, reaching in an almost ‘blind’ way the best optical performances.
We present a description of a new instrument development, HARPS3, planned to be installed on an upgraded and roboticized Isaac Newton Telescope by end-2018. HARPS3 will be a high resolution (R≃115,000) echelle spectrograph with a wavelength range from 380-690 nm. It is being built as part of the Terra Hunting Experiment - a future 10- year radial velocity measurement programme to discover Earth-like exoplanets. The instrument design is based on the successful HARPS spectrograph on the 3.6m ESO telescope and HARPS-N on the TNG telescope. The main changes to the design in HARPS3 will be: a customised fibre adapter at the Cassegrain focus providing a stabilised beam feed and on-sky fibre diameter ≈1:4 arcsec, the implementation of a new continuous ow cryostat to keep the CCD temperature very stable, detailed characterisation of the HARPS3 CCD to map the effective pixel positions and thus provide an improved accuracy wavelength solution, an optimised integrated polarimeter and the instrument integrated into a robotic operation. The robotic operation will optimise our programme which requires our target stars to be measured on a nightly basis. We present an overview of the entire project, including a description of our anticipated robotic operation.
ESPRESSO [1] is a high-resolution spectrograph under development for the VLT telescope. In general, the Optical Bench (OB) structure can be considered as a 3D one, conformed by welding thin plates of Structural Steel (St-52) with a nickelplated surface treatment, combined for getting maximum stiffness and minimum weight, that will be finally re-machined to get stringent geometrical and dimensional tolerances at I/Fs positions. TIG conventional welding procedure has been selected to minimize the cost and facilitate the own welding process. This solution follows the inheritance from HARPS [2] due to its success to achieve the required performance for the bench.
This paper contains an overview of the whole process of designing and manufacturing the Optical Bench of ESPRESSO, from the very first beginning with the specifications to the current status of the bench with its integration on the Spectrograph (including the Finite Element Models and the delivery of the final structure by the supplier) and lessons learned.
EMIR is the NIR imager and multiobject spectrograph being built as a common user instrument for the 10-m class GTC.
Big cryogenic instruments demand a reliable design and a specific hardware and software to increase its safety and
productivity.
EMIR vacuum, cooling and heating systems are monitored and partially controlled by a Programmable Logic Controller
(PLC) in industrial format with a touch screen. The PLC aids the instrument operator in the maintenance tasks
recovering autonomously vacuum if required or proposing preventive maintenance actions. The PLC and its associated
hardware improve EMIR safety having immediate reactions against eventual failure modes in the instrument or in
external supplies, including hardware failures during the heating procedure or failure in the PLC itself. EMIR PLC
provides detailed information periodically about status and alarms of vacuum and cooling components or external
supplies.
The High Optical Resolution Spectrograph (HORS) is a proposed high-resolution spectrograph for the
10-m Gran Telescopio Canarias (GTC) based on components from UES, a spectrograph which was in
use at the 4.2-m William Herschel Telescope (WHT) between 1992 and 2001.
HORS is designed as a cross-dispersed echelle spectrograph to observe in the range 380-800 nm with
a FWHM resolving power of about 50,000. HORS would operate on the GTC as a general-purpose
high-resolution spectrograph, and it would serve as a test-bed for some of the technologies proposed
for ESPRESSO – an ultra-high stability spectrograph planned for the Very Large Telescope (VLT) of
the European Southern Observatory.
The HORS spectrograph will be placed in the Coudé room, where it can enjoy excellent thermal and
mechanical stability, fiber fed from the Nasmyth focus, which is shared with OSIRIS. Inside the
spectrograph, incoming light will hit a small folder mirror before reaching the collimator. After a
second folder, the light will go through a set of three prisms and an Echelle grating before entering the
spectrograph camera and, finally, reaching the detector.
This manuscript contains a summary of the whole process that has transformed UES into HORS, with
all the mechanical and optical modifications that have been introduced to reach the final layout.
ESPRESSO is the next generation European exoplanet hunter, combining the efficiency of a modern echelle
spectrograph with extreme radial velocity and spectroscopic precision. The instrumental radial velocity precision will be
improved to reach 10 cm/s level, to achieve a gain of two magnitudes with respect to its predecessor HARPS.
The fiber-fed, non-rotating instrument will be installed in the Combined Coudé Laboratory of the VLT (Very Large
Telescope), which is situated in the Paranal Observatory (Chile).
The main challenge in the design of the optical mounts of the instrument has been the extreme long-term stability of big
rectangular optical components in a seismic environment.
This paper describes the requirements and the adopted solution for the opto-mechanical design of the collimator mirrors,
dichroic lens, field lens and cross dispersers of the instrument.
ESPRESSO is the next generation ground based European exoplanets hunter. It will combine the efficiency of modern
echelle spectrograph with extreme radial-velocity and spectroscopic precision. It will be installed at Paranal's VLT in
order to achieve two magnitudes gain with respect to its predecessor HARPS, and the instrumental radial-velocity
precision will be improved to reach 10 cm/s level. We have constituted a Consortium of astronomical research institutes
to fund, design and build ESPRESSO on behalf of and in collaboration with ESO, the European Southern Observatory.
The spectrograph will be installed at the Combined Coudé Laboratory (CCL) of the VLT, it will be linked to the four 8.2
meters Unit Telescopes through four optical "Coudé trains" and will be operated either with a single telescope or with up
to four UTs, enabling an additional 1.5 magnitude gain. Thanks to its characteristics and ability of combining
incoherently the light of 4 large telescopes, ESPRESSO will offer new possibilities in many fields of astronomy. Our
main scientific objectives are, however, the search and characterization of rocky exoplanets in the habitable zone of
quiet, near-by G to M-dwarfs, and the analysis of the variability of fundamental physical constants. The project is, for
most of its workpackages, in the procurement or development phases, and the CCL infrastructure is presently under
adaptation work. In this paper, we present the scientific objectives, the capabilities of ESPRESSO, the technical solutions
for the system and its subsystems. The project aspects of this facility are also described, from the consortium and
partnership structure to the planning phases and milestones.
ESPRESSO is the next European exoplanets hunter. It will combine the efficiency of modern echelle spectrograph with extreme radial-velocity precision. It will be installed at Paranal's VLT in order to achieve two magnitudes gain with respect to its predecessor HARPS, and the instrumental radial-velocity precision will be improved to reach 10 cm/s level. We have constituted a Consortium of astronomical research institutes to fund, design and build ESPRESSO on behalf of and in collaboration with ESO, the European Southern Observatory. The project has passed the final design review in May 2013. The spectrograph will be installed at the Combined Coudé Laboratory of the VLT, it will be linked to the four 8.2 meters Unit Telescopes through four optical "Coudé trains" and will be operated either with a single telescope or with up to four UTs, enabling an additional 1.5 magnitude gain. Thanks to its characteristics and ability of combining incoherently the light of 4 large telescopes, ESPRESSO will offer new possibilities in many fields of astronomy. Our main scientific objectives are, however, the search and characterization of rocky exoplanets in the habitable zone of quiet, near-by G to M-dwarfs, and the analysis of the variability of fundamental physical constants. In this paper, we will present the scientific objectives, the capabilities of ESPRESSO, the technical solutions for the system and its subsystems, enlightening the main differences between ESPRESSO and its predecessors. The project aspects of this facility are also described, from the consortium and partnership structure to the planning phases and milestones.
ESPRESSO, the VLT rocky exoplanets hunter, will combine the efficiency of modern echelle spectrograph with extreme
radial-velocity precision. It will be installed at Paranal on ESO's VLT in order to achieve a gain of two magnitudes with
respect to its predecessor HARPS, and the instrumental radial-velocity precision will be improved to reach 10 cm/s level.
We have constituted a Consortium of astronomical research institutes to fund, design and build ESPRESSO on behalf of
and in collaboration with ESO, the European Southern Observatory. The project has passed the preliminary design
review in November 2011. The spectrograph will be installed at the so-called "Combined Coudé Laboratory" of the
VLT, it will be linked to the four 8.2 meters Unit Telescopes (UT) through four optical "Coudé trains" and will be
operated either with a single telescope or with up to four UTs. In exchange of the major financial and human effort the
building Consortium will be awarded with guaranteed observing time (GTO), which will be invested in a common
scientific program. Thanks to its characteristics and the ability of combining incoherently the light of 4 large telescopes,
ESPRESSO will offer new possibilities in many fields of astronomy. Our main scientific objectives are, however, the search and characterization of rocky exoplanets in the habitable zone of quiet, near-by G to M-dwarfs, and the analysis
of the variability of fundamental physical constants. In this paper, we present the ambitious scientific objectives, the
capabilities of ESPRESSO, the technical solutions for the system and its subsystems, enlightening the main differences
between ESPRESSO and its predecessors. The project aspects of this facility are also described, from the consortium and
partnership structure to the planning phases and milestones.
ESPRESSO, the Echelle SPectrograph for Rocky Exoplanets and Stable Spectroscopic Observations, will combine the
efficiency of modern echelle spectrograph design with extreme radial-velocity precision. It will be installed on ESO's
VLT in order to achieve a gain of two magnitudes with respect to its predecessor HARPS, and the instrumental radialvelocity
precision will be improved to reach cm/s level. Thanks to its characteristics and the ability of combining
incoherently the light of 4 large telescopes, ESPRESSO will offer new possibilities in various fields of astronomy. The
main scientific objectives will be the search and characterization of rocky exoplanets in the habitable zone of quiet, nearby
G to M-dwarfs, and the analysis of the variability of fundamental physical constants. We will present the ambitious
scientific objectives, the capabilities of ESPRESSO, and the technical solutions of this challenging project.
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