An Adaptive Optics Search for Binaries in the Orion Nebula Cluster

ADAPTIVE OPTICS OBSERVATIONS OF 3 μm WATER ICE IN SILHOUETTE DISKS IN THE ORION NEBULA CLUSTER AND M43

The Astronomical Journal ◽

10.1088/0004-6256/144/6/175 ◽

2012 ◽

Vol 144 (6) ◽

pp. 175 ◽

Cited By ~ 4

Author(s):

Hiroshi Terada ◽

Alan T. Tokunaga ◽

Tae-Soo Pyo ◽

Yosuke Minowa ◽

Yutaka Hayano ◽

...

Keyword(s):

Adaptive Optics ◽

Orion Nebula ◽

Water Ice

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Binary Stars in the Orion Nebula Cluster

Proceedings of the International Astronomical Union ◽

10.1017/s1743921307003912 ◽

2006 ◽

Vol 2 (S240) ◽

pp. 114-116

Author(s):

Rainer Köhler ◽

Monika G. Petr-Gotzens ◽

Mark J. McCaughrean ◽

Jerome Bouvier ◽

Gaspard Duchêne ◽

...

Keyword(s):

Adaptive Optics ◽

Binary Stars ◽

Main Sequence ◽

Cluster Center ◽

Orion Nebula ◽

Low Mass Stars ◽

Star Forming ◽

Star Forming Regions ◽

Low Mass ◽

Guide Star

AbstractWe report on a high-spatial-resolution survey for binary stars in the periphery of the Orion Nebula Cluster, at 5–15 arcmin (0.65 – 2 pc) from the cluster center. We observed 228 stars with adaptive optics systems, in order to find companions at separations of 0.13 – 1.12 arcsec (60 – 500 AU), and detected 13 new binaries. Combined with the results of Petr (1998), we have a sample of 275 objects, about half of which have masses from the literature and high probabilities to be cluster members. We used an improved method to derive the completeness limits of the observations, which takes into account the elongated point spread function of stars at relatively large distances from the adaptive optics guide star. The multiplicity of stars with masses >2 M⊙ is found to be significantly larger than that of low-mass stars. The companion star frequency of low-mass stars is comparable to that of main-sequence M-dwarfs, less than half that of solar-type main-sequence stars, and 3.5 to 5 times lower than in the Taurus-Auriga and Scorpius-Centaurus star-forming regions. We find the binary frequency of low-mass stars in the periphery of the cluster to be the same or only slightly higher than for stars in the cluster core (< 3′ from θ1C Ori). This is in contrast to the prediction of the theory that the low binary frequency in the cluster is caused by the disruption of binaries due to dynamical interactions. There are two ways out of this dilemma: Either the initial binary frequency in the Orion Nebula Cluster was lower than in Taurus-Auriga, or the Orion Nebula Cluster was originally much denser and dynamically more active. A detailed report of this work has been published in Astronomy & Astrophysics (Köhler et al. 2006).

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Adaptive optics (astronomy)

AccessScience ◽

10.1036/1097-8542.yb990105 ◽

2015 ◽

Keyword(s):

Adaptive Optics

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Adaptive optics with adaptive filtering and control

Proceedings of the 2004 American Control Conference ◽

10.23919/acc.2004.1384398 ◽

2004 ◽

Author(s):

Yu-Tai Liu ◽

S. Gibson

Keyword(s):

Adaptive Optics ◽

Adaptive Filtering ◽

And Control

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Accounting for mirror dynamics in optimal Adaptive Optics control

2009 European Control Conference (ECC) ◽

10.23919/ecc.2009.7074944 ◽

2009 ◽

Cited By ~ 1

Author(s):

Carlos Correia ◽

Henri-Francois Raynaud ◽

Caroline Kulcsar ◽

Jean-Marc Conan

Keyword(s):

Adaptive Optics

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The Condition for Absolute Stability of an Electroelastic Actuator Control System for Nanomechatronics

Elektrichestvo ◽

10.24160/0013-5380-2020-10-52-58 ◽

2020 ◽

Vol 10 (10) ◽

pp. 52-58

Author(s):

Sergey M. AFONIN ◽

Keyword(s):

Control System ◽

Adaptive Optics ◽

Absolute Stability ◽

Deformation Characteristic ◽

Straight Line Segment ◽

Control Mechanisms ◽

Relative Width ◽

Random Inputs ◽

Deformation Control ◽

Actuator Control

An electroelastic actuator for nanomechatronics is used in nanotechnology, adaptive optics, microsurgery, microelectronics, and biomedicine to actuate or control mechanisms, systems based on the electroelastic effect, and to convert electrical signals into mechanical displacements and forces. In nanomechatronic systems, a piezoactuator is used in scanning microscopy, laser systems, in astronomy for precision alignment, for compensation of temperature, gravitational deformations and atmospheric turbulence, focusing, and stabilizing the image. In this study, a condition for absolute stability of an electroelastic actuator control system for nanomechatronics under deterministic and random inputs is obtained. A number of equilibrium positions in an electroelastic actuator mechatronic control system are found, the totality of which is represented by a straight line segment. The electroelastic actuator’s deformation control system dead band relative width is determined for the actuator’s symmetric and asymmetric hysteresis characteristics. Under deterministic inputs and with fulfilling the condition for the derivative of the nonlinear hysteresis actuator deformation characteristic, the set of equilibrium positions of the electroelastic actuator control system for nanomechatronics is absolutely stable. Under random inputs, the system absolute stability with respect to the mathematical expectations of the electroelastic actuator mechatronic control system equilibrium positions has been determined subject to fulfilling the condition on the derivative of the actuator hysteresis characteristic.

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