scholarly journals Keck Adaptive Optics Imaging of Nearby Young Stars: Detection of Close Multiple Systems

2003 ◽  
Vol 126 (4) ◽  
pp. 2009-2014 ◽  
Author(s):  
Alexis Brandeker ◽  
Ray Jayawardhana ◽  
Joan Najita
Keyword(s):  
Adaptive Optics ◽  
Young Stars ◽  
Multiple Systems ◽  
Adaptive Optics Imaging

scholarly journals Close Companions to Nearby Young Stars from Adaptive Optics Imaging on VLT and Keck

2005 ◽  
pp. 177-182 ◽  
Author(s):  
Karl E. Haisch ◽  
Ray Jayawardhana ◽  
Alexis Brandeker ◽  
Diego Mardones
Keyword(s):  
Adaptive Optics ◽  
Young Stars ◽  
Adaptive Optics Imaging

scholarly journals The effect of stellar multiplicity on protoplanetary discs: a near-infrared survey of the Lupus star-forming region

2020 ◽  
Vol 501 (2) ◽  
pp. 2305-2315
Author(s):  
Alice Zurlo ◽  
Lucas A Cieza ◽  
Megan Ansdell ◽  
Valentin Christiaens ◽  
Sebastián Pérez ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Molecular Cloud ◽  
Near Infrared ◽  
Main Sequence Stars ◽  
Multiple Systems ◽  
Star Forming ◽  
Very Large Telescope ◽  
Pms Stars ◽  
First Time ◽  
Infrared Survey

ABSTRACT We present results from a near-infrared (NIR) adaptive optics (AO) survey of pre-main-sequence stars in the Lupus molecular cloud with NACO at the Very Large Telescope (VLT) to identify (sub)stellar companions down to ∼20-au separation and investigate the effects of multiplicity on circumstellar disc properties. We observe for the first time in the NIR with AO a total of 47 targets and complement our observations with archival data for another 58 objects previously observed with the same instrument. All 105 targets have millimetre Atacama Large Millimetre/sub-millimetre Array (ALMA) data available, which provide constraints on disc masses and sizes. We identify a total of 13 multiple systems, including 11 doubles and 2 triples. In agreement with previous studies, we find that the most massive (Mdust > 50 M⊕) and largest (Rdust > 70 au) discs are only seen around stars lacking visual companions (with separations of 20–4800 au) and that primaries tend to host more massive discs than secondaries. However, as recently shown in a very similar study of >200 PMS stars in the Ophiuchus molecular cloud, the distributions of disc masses and sizes are similar for single and multiple systems for Mdust < 50 M⊕ and radii Rdust < 70 au. Such discs correspond to ∼80–90 per cent of the sample. This result can be seen in the combined sample of Lupus and Ophiuchus objects, which now includes more than 300 targets with ALMA imaging and NIR AO data, and implies that stellar companions with separations >20 au mostly affect discs in the upper 10${{\ \rm per\ cent}}$ of the disc mass and size distributions.

scholarly journals A method for space-variant deblurring with application to adaptive optics imaging in astronomy

2015 ◽  
Vol 579 ◽  
pp. A1 ◽  
Author(s):  
A. La Camera ◽  
L. Schreiber ◽  
E. Diolaiti ◽  
P. Boccacci ◽  
M. Bertero ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Adaptive Optics Imaging ◽  
Space Variant

scholarly journals Multi-conjugated adaptive optics imaging of distant galaxies –  a comparison of Gemini/GSAOI and VLT/HAWK-I data

2017 ◽  
Vol 472 (1) ◽  
pp. 217-223 ◽  
Author(s):  
Mischa Schirmer ◽  
Vincent Garrel ◽  
Gaetano Sivo ◽  
Eduardo Marin ◽  
Eleazar R. Carrasco
Keyword(s):  
Adaptive Optics ◽  
Distant Galaxies ◽  
Adaptive Optics Imaging

scholarly journals Laser-Guide-Star Satellite for Ground-Based Adaptive Optics Imaging of Geosynchronous Satellites

2017 ◽  
Vol 54 (3) ◽  
pp. 621-639 ◽  
Author(s):  
Weston A. Marlow ◽  
Ashley K. Carlton ◽  
Hyosang Yoon ◽  
James R. Clark ◽  
Christian A. Haughwout ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Laser Guide Star ◽  
Adaptive Optics Imaging ◽  
Guide Star ◽  
Laser Guide ◽  
Geosynchronous Satellites

scholarly journals Probing post-AGB metamorphosis with NIR Adaptive Optics Imaging

2006 ◽  
Vol 2 (S234) ◽  
pp. 71 ◽  
Author(s):  
C. Sánchez Contreras ◽  
D. Le Mignant ◽  
R. Sahai ◽  
F. H. Chaffee ◽  
M. Morris
Keyword(s):  
Adaptive Optics ◽  
Adaptive Optics Imaging

scholarly journals Closing the gap between Earth-based and interplanetary mission observations: Vesta seen by VLT/SPHERE

2019 ◽  
Vol 623 ◽  
pp. A6 ◽  
Author(s):  
R. JL. Fétick ◽  
L. Jorda ◽  
P. Vernazza ◽  
M. Marsset ◽  
A. Drouard ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Spatial Resolution ◽  
Ground Truth ◽  
Space Mission ◽  
Contour Extraction ◽  
Dawn Mission ◽  
The North ◽  
Adaptive Optics Imaging ◽  
Interplanetary Missions

Context. Over the past decades, several interplanetary missions have studied small bodies in situ, leading to major advances in our understanding of their geological and geophysical properties. These missions, however, have had a limited number of targets. Among them, the NASA Dawn mission has characterised in detail the topography and albedo variegation across the surface of asteroid (4) Vesta down to a spatial resolution of ~20 m pixel−1 scale. Aims. Here our aim was to determine how much topographic and albedo information can be retrieved from the ground with VLT/SPHERE in the case of Vesta, having a former space mission (Dawn) providing us with the ground truth that can be used as a benchmark. Methods. We observed Vesta with VLT/SPHERE/ZIMPOL as part of our ESO large programme (ID 199.C-0074) at six different epochs, and deconvolved the collected images with a parametric point spread function (PSF). We then compared our images with synthetic views of Vesta generated from the 3D shape model of the Dawn mission, on which we projected Vesta’s albedo information. Results. We show that the deconvolution of the VLT/SPHERE images with a parametric PSF allows the retrieval of the main topographic and albedo features present across the surface of Vesta down to a spatial resolution of ~20–30 km. Contour extraction shows an accuracy of ~1 pixel (3.6 mas). The present study provides the very first quantitative estimate of the accuracy of ground-based adaptive-optics imaging observations of asteroid surfaces. Conclusions. In the case of Vesta, the upcoming generation of 30–40 m telescopes (ELT, TMT, GMT) should in principle be able to resolve all of the main features present across its surface, including the troughs and the north–south crater dichotomy, provided that they operate at the diffraction limit.

scholarly journals Kepler-411: a four-planet system with an active host star

2019 ◽  
Vol 624 ◽  
pp. A15 ◽  
Author(s):  
L. Sun ◽  
P. Ioannidis ◽  
S. Gu ◽  
J. H. M. M. Schmitt ◽  
X. Wang ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Detailed Characterization ◽  
Dynamical Interaction ◽  
Transiting Planets ◽  
Imaging Results ◽  
Adaptive Optics Imaging ◽  
Dynamical Simulations ◽  
Mutual Inclination ◽  
Rocky Planets

We present a detailed characterization of the Kepler-411 system (KOI 1781). This system was previously known to host two transiting planets: one with a period of 3 days (R = 2.4 R⊕; Kepler-411b) and one with a period of 7.8 days (R = 4.4 R⊕; Kepler-411c), as well as a transiting planetary candidate with a 58-day period (R = 3.3 R⊕; KOI 1781.03) from Kepler photometry. Here, we combine Kepler photometry data and new transit timing variation (TTV) measurements from all the Kepler quarters with previous adaptive-optics imaging results, and dynamical simulations, in order to constrain the properties of the Kepler-411 system. From our analysis, we obtain masses of 25.6 ± 2.6 M⊕ for Kepler-411b and 26.4 ± 5.9 M⊕ for Kepler-411c, and we confirm the planetary nature of KOI 1781.03 with a mass of 15.2 ± 5.1 M⊕, hence the name Kepler-411d. Furthermore, by assuming near-coplanarity of the system (mutual inclination below 30°), we discover a nontransiting planet, Kepler-411e, with a mass of 10.8 ± 1.1 M⊕ on a 31.5-day orbit, which has a strong dynamical interaction with Kepler-411d. With densities of 1.71 ± 0.39 g cm−3 and 2.32 ± 0.83 g cm−3, both Kepler-411c and Kepler-411d belong to the group of planets with a massive core and a significant fraction of volatiles. Although Kepler-411b has a sub-Neptune size, it belongs to the group of rocky planets.

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