Adaptive optics for the European very large telescope

Author(s):  
Fritz Merkle ◽  
Norbert N. Hubin
2019 ◽  
Vol 629 ◽  
pp. A41 ◽  
Author(s):  
J. Woillez ◽  
J. A. Abad ◽  
R. Abuter ◽  
E. Aller Carpentier ◽  
J. Alonso ◽  
...  

Context. The tip-tilt stabilisation system of the 1.8 m Auxiliary Telescopes of the Very Large Telescope Interferometer was never dimensioned for robust fringe tracking, except when atmospheric seeing conditions are excellent. Aims. Increasing the level of wavefront correction at the telescopes is expected to improve the coupling into the single-mode fibres of the instruments, and enable robust fringe tracking even in degraded conditions. Methods. We deployed a new adaptive optics module for interferometry (NAOMI) on the Auxiliary Telescopes. Results. We present its design, performance, and effect on the observations that are carried out with the interferometric instruments.


2011 ◽  
Vol 737 (1) ◽  
pp. 31 ◽  
Author(s):  
Sergio Ortolani ◽  
Beatriz Barbuy ◽  
Yazan Momany ◽  
Ivo Saviane ◽  
Eduardo Bica ◽  
...  

1994 ◽  
Author(s):  
Norbert N. Hubin ◽  
Bertrand Theodore ◽  
Patrick Petitjean ◽  
Bernard Delabre

2020 ◽  
Vol 498 (1) ◽  
pp. 737-749
Author(s):  
Subhajeet Karmakar ◽  
A S Rajpurohit ◽  
F Allard ◽  
D Homeier

ABSTRACT Using the high-resolution near-infrared adaptive optics imaging from the NaCo instrument at the Very Large Telescope, we report the discovery of a new binary companion to the M-dwarf LP 1033-31 and also confirm the binarity of LP 877-72. We have characterized both the stellar systems and estimated the properties of their individual components. We have found that LP 1033-31 AB with the spectral type of M4.5+M4.5 has a projected separation of 6.7 ± 1.3 AU. Whereas with the spectral type of M1+M4, the projected separation of LP 877-72 AB is estimated to be 45.8 ± 0.3 AU. The binary companions of LP 1033-31 AB are found to have similar masses, radii, effective temperatures, and log g with the estimated values of 0.20 ± 0.04 $\rm {M}_{\odot }$, 0.22 ± 0.03 $\rm {R}_{\odot }$, and 3200 K, 5.06 ± 0.04. However, the primary of LP 877-72 AB is found to be twice as massive as the secondary with the derived mass of 0.520 ± 0.006 $\rm {M}_{\odot }$. The radius and log g for the primary of LP 877-72 AB are found to be 1.8 and 0.95 times that of the secondary component with the estimated values of 0.492 ± 0.011 $\rm {R}_{\odot }$ and 4.768 ± 0.005, respectively. With an effective temperature of 3750 ± 15 K, the primary of LP 877-72 AB is also estimated to be ∼400 K hotter than the secondary component. We have also estimated the orbital period of LP 1033-31 and LP 877-72 to be ∼28 and ∼349 yr, respectively. The binding energies for both systems are found to be >1043 erg, which signifies that both systems are stable.


1994 ◽  
Vol 158 ◽  
pp. 143-150
Author(s):  
T. R. Bedding ◽  
J. M. Beckers ◽  
M. Faucherre ◽  
N. Hubin ◽  
B. Koehler ◽  
...  

One of the observing modes available with the ESO Very Large Telescope will be coherent combination of the light received by up to four 8 m unit telescopes and several 1.8 m auxiliary telescopes. The location of the main telescopes is fixed, while auxiliary telescopes can be moved among some 30 observing stations. The locations of these stations were chosen to augment the (u, v) coverage of the unit telescopes as well as to function as an independent interferometric array.The 8 m telescopes will be equipped with adaptive optics to correct for seeing-induced wavefront aberrations. This wavefront correction will be complete at near-infrared wavelengths, giving the interferometer very high sensitivity in this spectral regime. This paper gives a brief description of the VLT Interferometer and an update on its status.


1984 ◽  
Vol 79 ◽  
pp. 789-816
Author(s):  
Robert G. Tull

In late 1979 a plan to build a very large telescope was presented to University of Texas President Peter Flawn. A small startup budget was subsequently granted by the University administration, and we asked Aden and Marjorie Meinel to carry out a design concept study, which they completed in early 1980. Following their report, a study contract was awarded to the Western Development Laboratories Division of Ford Aerospace & Communications Corp., for a preliminary design and cost estimate.It is generally agreed that construction of monolithic mirrors up to 8-10 meters aperture is within current technology. The major concern that has prevented construction of telescopes larger than the Palomar 5-m telescope outside the Soviet Union has been cost; it has been shown (Meinel and Meinel, 1980a) that the single most important item in determining the cost of a large telescope is the weight of its primary mirror. We chose a monolithic, lightweight 7.6-m (300-inch) mirror as representing a significant advance from presently existing telescope apertures while also being well within the current state-of-the-art. Because a lightweight mirror cannot support its figure against gravity and other disturbances as well as can a conventional thick mirror, we have investigated methods of active control of the mirror's figure. The now maturing technology of adaptive optics (Hardy 1980, 1981, 1982) has been drawn upon extensively in planning this telescope. Results of finite element analyses of an ultra-lightweight monolithic 7.6-m mirror blank have been published (Ray et.al., 1982, 1983). A description of the proposed mirror figure monitoring system has been given (Tull and Young, 1983).


1984 ◽  
Vol 79 ◽  
pp. 767-787
Author(s):  
Daniel Enard

VLT preliminary studies were initiated at ESO as early as 1978 (1). After ESO's move from Geneva to Munich (1980) a study group chaired first by R. Wilson, then by J.P. Swings was set up and among a number of conceptual ideas that were analysed, the concept of a “limited array” emerged as the most attractive (2). A significant driver was then, interferometry; however after a theoretical analysis performed by F. Roddier and P. Lena (3), it became clear that interferometry with large telescopes would not be cost-effective in the visible range. In the IR, the situation would be more favorable but the overall efficiency would depend on factors that are not reliably known at present. The conclusion was that it might be difficult to justify a huge investment too exclusively oriented towards interferometry, such as an array of movable large telescopes, but on the other hand the possibility of a coherent coupling in the IR should be maintained as a prime requirement since new developments in detectors and in adaptive optics could make it effective and scientifically very rewarding.


2003 ◽  
Author(s):  
Nancy Ageorges ◽  
Rainer Lenzen ◽  
Markus Hartung ◽  
Wolfgang Brandner ◽  
Eric Gendron ◽  
...  

2019 ◽  
Vol 631 ◽  
pp. A155 ◽  
Author(s):  
J.-L. Beuzit ◽  
A. Vigan ◽  
D. Mouillet ◽  
K. Dohlen ◽  
R. Gratton ◽  
...  

Observations of circumstellar environments that look for the direct signal of exoplanets and the scattered light from disks have significant instrumental implications. In the past 15 years, major developments in adaptive optics, coronagraphy, optical manufacturing, wavefront sensing, and data processing, together with a consistent global system analysis have brought about a new generation of high-contrast imagers and spectrographs on large ground-based telescopes with much better performance. One of the most productive imagers is the Spectro-Polarimetic High contrast imager for Exoplanets REsearch (SPHERE), which was designed and built for the ESO Very Large Telescope (VLT) in Chile. SPHERE includes an extreme adaptive optics system, a highly stable common path interface, several types of coronagraphs, and three science instruments. Two of them, the Integral Field Spectrograph (IFS) and the Infra-Red Dual-band Imager and Spectrograph (IRDIS), were designed to efficiently cover the near-infrared range in a single observation for an efficient search of young planets. The third instrument, ZIMPOL, was designed for visible polarimetric observation to look for the reflected light of exoplanets and the light scattered by debris disks. These three scientific instruments enable the study of circumstellar environments at unprecedented angular resolution, both in the visible and the near-infrared. In this work, we thoroughly present SPHERE and its on-sky performance after four years of operations at the VLT.


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