scholarly journals Visible Light Adaptive Optics Imaging of the Orion 218-354 Silhouette Disk

2013 ◽  
Vol 8 (S299) ◽  
pp. 159-160
Author(s):  
Katherine B. Follette ◽  
Laird M. Close ◽  
Jared R. Males ◽  
Derek Kopon ◽  
Ya-Lin Wu ◽  
...  
Keyword(s):  
High Resolution ◽  
Visible Light ◽  
Adaptive Optics ◽  
Central Star ◽  
Full Detail ◽  
Imaging Analysis ◽  
Large Telescope ◽  
Disk Structure ◽  
Adaptive Optics Imaging ◽  
Differential Imaging

AbstractWe present the first ground-based adaptive optics images of a silhouette disk. This disk, Orion 218-354, is seen in silhouette against the bright nebular background of Orion, and was resolved using the new Magellan Adaptive Secondary AO system and its VisAO camera in Simultaneous Differential Imaging (SDI) mode. PSF subtraction of Orion 218-354 reveals a disk ~1″ (400 AU) in radius, with the degree of absorption increasing steadily towards the center of the disk. By virtue of the central star being unsaturated, these data probe inward to a much smaller radius than previous HST images. Our data present a different picture than previous observers had hypothesized, namely that the disk is likely optically thin at Hα at least as far inward as ~20AU. In addition to being among the first high-resolution AO images taken in the optical on a large telescope, these data reveal the power of SDI imaging to illuminate disk structure, and speak to a bright future for visible AO imaging. Analysis of the results described briefly here can be found in full detail in Follette et al. (2013).

scholarly journals Searching for Hα emitting sources around MWC 758

2018 ◽  
Vol 613 ◽  
pp. L5 ◽  
Author(s):  
N. Huélamo ◽  
G. Chauvin ◽  
H. M. Schmid ◽  
S. P. Quanz ◽  
E. Whelan ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Mass Range ◽  
Position Angle ◽  
Central Star ◽  
Young Star ◽  
Upper Limit ◽  
T Tauri ◽  
Very Large Telescope ◽  
Accretion Rates ◽  
Differential Imaging

Context. MWC 758 is a young star surrounded by a transitional disk. The disk shows an inner cavity and spiral arms that could be caused by the presence of protoplanets. Recently, a protoplanet candidate has been detected around MWC 758 through high-resolution L′-band observations. The candidate is located inside the disk cavity at a separation of ~111 mas from the central star, and at an average position angle of ~165.5°. Aims. We aim at detecting accreting protoplanet candidates within the disk of MWC 758 through angular spectral differential imaging (ASDI) observations in the optical regime. In particular, we explore the emission at the position of the detected planet candidate. Methods. We have performed simultaneous adaptive optics observations in the Hα line and the adjacent continuum using SPHERE/ZIMPOL at the Very Large Telescope (VLT). Results. The data analysis does not reveal any Hα signal around the target. The derived contrast curve in the B_Ha filter allows us to derive a 5σ upper limit of ~7.6 mag at 111 mas, the separation of the previously detected planet candidate. This contrast translates into a Hα line luminosity of LHα ≲ 5×10−5 L⊙ at 111 mas. Assuming that LHα scales with Lacc as in classical T Tauri stars (CTTSs) as a first approximation, we can estimate an accretion luminosity of Lacc < 3.7 × 10−4 L⊙ for the protoplanet candidate. For the predicted mass range of MWC 758b, 0.5–5 MJup, this implies accretion rates smaller than Ṁ < 3.4 × (10−8−10−9)M⊙ yr−1, for an average planet radius of 1.1 RJup. Therefore, our estimates are consistent with the predictions of accreting circumplanetary accretion models for Rin = 1RJup. The ZIMPOL line luminosity is consistent with the Hα upper limit predicted by these models for truncation radii ≲3.2 RJup. Conclusions. The non-detection of any Hα emitting source in the ZIMPOL images does not allow us to unveil the nature of the L′ detected source. Either it is a protoplanet candidate or a disk asymmetry.

scholarly journals Adaptive optics imaging system based on a high-resolution liquid crystal on silicon device

2006 ◽  
Vol 14 (18) ◽  
pp. 8013 ◽  
Author(s):  
Quanquan Mu ◽  
Zhaoliang Cao ◽  
Lifa Hu ◽  
Dayu Li ◽  
Li Xuan
Keyword(s):  
Liquid Crystal ◽  
High Resolution ◽  
Adaptive Optics ◽  
Imaging System ◽  
Adaptive Optics Imaging ◽  
Liquid Crystal On Silicon ◽  
Silicon Device

scholarly journals CFHT Adaptive Optics Imaging of Active Galaxies

1999 ◽  
Vol 186 ◽  
pp. 345-347
Author(s):  
J.B. Hutchings
Keyword(s):  
Visible Light ◽  
Adaptive Optics ◽  
Light Guide ◽  
Diffraction Limit ◽  
Angular Distance ◽  
Active Galaxies ◽  
Adaptive Optics Imaging ◽  
Guide Star

The CFHT adaptive optics camera uses a visible light guide signal from a star to operate a bimorph mirror. The system is a unit that is operated by the observer and can be used with CCD or HgCdTe detectors. Pixel sizes are of order 0.04″. The amount of correction varies as the guide star brightness, the angular distance from it, and the natural seeing at the time. With good CFHT conditions, a guide star of 13 mag will give JHK images of FWHM near to the diffraction limit (0.1 to 0.15″) up to 20″ away. Correction is worse in the optical, but images of 0.2″ or better can be obtained in R and I-band. The camera performance is described by Rigaut et al (1998).

scholarly journals Detection and characterization of two VLM binaries: LP 1033-31 and LP 877-72

2020 ◽  
Vol 498 (1) ◽  
pp. 737-749
Author(s):  
Subhajeet Karmakar ◽  
A S Rajpurohit ◽  
F Allard ◽  
D Homeier
Keyword(s):  
Adaptive Optics ◽  
Spectral Type ◽  
Near Infrared ◽  
Binding Energies ◽  
Secondary Component ◽  
Large Telescope ◽  
Very Large Telescope ◽  
Adaptive Optics Imaging ◽  
M Dwarf

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 &gt;1043 erg, which signifies that both systems are stable.

scholarly journals High-Resolution, Adaptive Optics Imaging of the Human Trabecular Meshwork In Vivo

2019 ◽  
Vol 8 (5) ◽  
pp. 5 ◽  
Author(s):  
Brett J. King ◽  
Stephen A. Burns ◽  
Kaitlyn A. Sapoznik ◽  
Ting Luo ◽  
Thomas J. Gast
Keyword(s):  
High Resolution ◽  
Adaptive Optics ◽  
Trabecular Meshwork ◽  
Adaptive Optics Imaging

scholarly journals The Surface of Titan from Adaptive Optics Observations

2002 ◽  
Vol 12 ◽  
pp. 629
Author(s):  
Seran G. Gibbard ◽  
Bruce A. Macintosh ◽  
Claire E. Max ◽  
Henry Roe ◽  
Imke de Pater ◽  
...  
Keyword(s):  
High Resolution ◽  
Solar System ◽  
Visible Light ◽  
Adaptive Optics ◽  
Surface Albedo ◽  
Near Infrared ◽  
High Resolution Spectroscopy ◽  
Surface Features ◽  
Infrared Wavelengths ◽  
Adaptive Optics System

AbstractSaturn’s largest moon Titan is the only satellite in the Solar System with a substantial atmosphere. Photolysis of methane creates a hydrocarbon haze in Titan’s atmosphere that is opaque to visible light. The new adaptive optics system on the 10–meter W. M. Keck Telescope enables us to observe Titan with a resolution of 0.04 arcseconds, or 20 resolution elements across the disk. By observing at near-infrared wavelengths that are methane band windows we can see through Titan’s hydrocarbon haze to the surface beneath. Recent adaptive optics images of Titan both in broadband (J, H, and K) filters and in narrowband filters that selectively probe Titan’s surface and atmosphere allow us to determine surface albedo and properties of the hydrocarbon haze layer. Future observations will include high-resolution spectroscopy coupled with adaptive optics to obtain spectra of individual surface features.

scholarly journals VERY LARGE TELESCOPE/NACO POLARIMETRIC DIFFERENTIAL IMAGING OF HD100546—DISK STRUCTURE AND DUST GRAIN PROPERTIES BETWEEN 10 AND 140 AU

2011 ◽  
Vol 738 (1) ◽  
pp. 23 ◽  
Author(s):  
Sascha P. Quanz ◽  
Hans Martin Schmid ◽  
Kerstin Geissler ◽  
Michael R. Meyer ◽  
Thomas Henning ◽  
...  
Keyword(s):  
Large Telescope ◽  
Disk Structure ◽  
Very Large Telescope ◽  
Dust Grain ◽  
Grain Properties ◽  
Differential Imaging
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