scholarly journals precision: a fast python pipeline for high-contrast imaging – application to SPHERE observations of the red supergiant VX Sagitariae

2020 ◽  
Vol 494 (3) ◽  
pp. 3200-3211
Author(s):  
P Scicluna ◽  
F Kemper ◽  
R Siebenmorgen ◽  
R Wesson ◽  
J A D L Blommaert ◽  
...  
Keyword(s):  
Near Infrared ◽  
Extrasolar Planets ◽  
Asymmetric Structure ◽  
High Contrast ◽  
Contrast Imaging ◽  
Near Ir ◽  
High Contrast Imaging ◽  
Infrared Imager ◽  
Imaging Application ◽  
Efficient Reduction

ABSTRACT The search for extrasolar planets has driven rapid advances in instrumentation, resulting in cameras such as SPHERE at the VLT, GPI at Gemini South and SCExAO at Subaru, capable of achieving very high contrast (∼106) around bright stars with small inner working angles (${\sim}0.1\,{\rm arcsec}$). The optimal exploitation of data from these instruments depends on the availability of easy-to-use software to process and analyse their data products. We present a pure-python pipeline, precision, which provides fast, memory-efficient reduction of data from the SPHERE/IRDIS near-infrared imager, and can be readily extended to other instruments. We apply precision to observations of the extreme red supergiant VX Sgr, the inner outflow of which is revealed to host complex, asymmetric structure in the near-IR. In addition, optical polarimetric imaging reveals clear extended polarized emission on ∼0.5 arcsec scales that varies significantly with azimuth, confirming the asymmetry. While not conclusive, this could suggest that the ejecta are confined to a disc or torus, which we are viewing nearly face on, although other non-spherical or clumpy configurations remain possible. VX Sgr has no known companions, making such a geometry difficult to explain, as there is no obvious source of angular momentum in the system.

scholarly journals Detecting and Characterizing Exoplanets with Direct Imaging: Past, Present, and Future

2013 ◽  
Vol 8 (S299) ◽  
pp. 1-11 ◽  
Author(s):  
Beth Biller
Keyword(s):  
Extrasolar Planets ◽  
Direct Detection ◽  
High Mass ◽  
High Contrast ◽  
Future Prospects ◽  
Contrast Imaging ◽  
Direct Imaging ◽  
Planet Detection ◽  
High Contrast Imaging ◽  
Imaging And Spectroscopy

AbstractThe last decade has yielded the first images of exoplanets, considerably advancing our understanding of the properties of young giant planets. In this talk I will discuss current results from ongoing direct imaging efforts as well as future prospects for detection and characterization of exoplanets via high contrast imaging. Direct detection, and direct spectroscopy in particular, have great potential for advancing our understanding of extrasolar planets. In combination with other methods of planet detection, direct imaging and spectroscopy will allow us to eventually: 1) study the physical properties of exoplanets (colors, temperatures, etc.) in depth and 2) fully map out the architecture of typical planetary systems. Direct imaging has offered us the first glimpse into the atmospheric properties of young high-mass (3-10 MJup) exoplanets. Deep direct imaging surveys for exoplanets have also yielded the strongest constraints to date on the statistical properties of wide giant exoplanets. A number of extremely high contrast exoplanet imaging instruments have recently come online or will come online within the next year (including Project 1640, SCExAO, SPHERE, GPI, among others). I will discuss future prospects with these instruments.

High contrast imaging with IRDIS near infrared polarimeter

2010 ◽  
Author(s):  
M. Langlois ◽  
K. Dohlen ◽  
J.-C. Augereau ◽  
D. Mouillet ◽  
A. Boccaletti ◽  
...  
Keyword(s):  
Near Infrared ◽  
High Contrast ◽  
Contrast Imaging ◽  
High Contrast Imaging

scholarly journals Characterization of a photon counting EMCCD for space-based high contrast imaging spectroscopy of extrasolar planets

2014 ◽  
Author(s):  
Ashlee N. Wilkins ◽  
Michael W. McElwain ◽  
Timothy J. Norton ◽  
Bernie J. Rauscher ◽  
Johannes F. Rothe ◽  
...  
Keyword(s):  
Extrasolar Planets ◽  
Imaging Spectroscopy ◽  
Photon Counting ◽  
High Contrast ◽  
Contrast Imaging ◽  
High Contrast Imaging

scholarly journals Origin of the asymmetry of the wind driven halo observed in high-contrast images

2018 ◽  
Vol 620 ◽  
pp. L10 ◽  
Author(s):  
F. Cantalloube ◽  
E. H. Por ◽  
K. Dohlen ◽  
J.-F. Sauvage ◽  
A. Vigan ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Predictive Control ◽  
Near Infrared ◽  
Control Algorithms ◽  
Circumstellar Disk ◽  
High Contrast ◽  
Contrast Imaging ◽  
High Contrast Imaging ◽  
The Asymmetry ◽  
Processing Techniques

The latest generation of high-contrast instruments dedicated to exoplanets and circumstellar disk imaging are equipped with extreme adaptive optics and coronagraphs to reach contrasts of up to 10−4 at a few tenths of arcseconds in the near-infrared. The resulting image shows faint features, only revealed with this combination, such as the wind driven halo. The wind driven halo is due to the lag between the adaptive optics correction and the turbulence speed over the telescope pupil. However, we observe an asymmetry of this wind driven halo that was not expected when the instrument was designed. In this letter, we describe and demonstrate the physical origin of this asymmetry and support our explanation by simulating the asymmetry with an end-to-end approach. From this work, we find that the observed asymmetry is explained by the interference between the AO-lag error and scintillation effects, mainly originating from the fast jet stream layer located at about 12 km in altitude. Now identified and interpreted, this effect can be taken into account for further design of high-contrast imaging simulators, next generation or upgrade of high-contrast instruments, predictive control algorithms for adaptive optics, or image post-processing techniques.

scholarly journals Adaptive Optics Imaging of Circumstellar Environments

2004 ◽  
Vol 221 ◽  
pp. 307-312
Author(s):  
Dániel Apai ◽  
Ilaria Pascucci ◽  
Hongchi Wang ◽  
Wolfgang Brandner ◽  
Thomas Henning ◽  
...  
Keyword(s):  
High Resolution ◽  
Adaptive Optics ◽  
Near Infrared ◽  
Infrared Imaging ◽  
Circumstellar Disks ◽  
Circumstellar Envelope ◽  
High Contrast ◽  
Contrast Imaging ◽  
High Contrast Imaging ◽  
Circumstellar Environments

We present results from our high-resolution, high-contrast imaging campaign targeting the circumstellar environments of young, nearby stars of different masses. The observations have been conducted using the ALFA/CA 3.5m and NACO UT4/VLT adaptive optics systems. In order to enhance the contrast we applied the methods PSF-subtraction and polarimetric differential imaging (PDI). The observations of young stars yielded the identification of numerous new companion candidates, the most interesting one being ∼ 0.5″ from FU Ori. We also obtained high-resolution near-infrared imaging of the circumstellar envelope of SU Aur and AB Aur. Our PDI of the TW Hya circumstellar disk traced back the disk emission as close as 0.1″ ≃ 6 AU from the star, the closest yet. Our results demonstrate the potential of the adaptive optics systems in achieving high-resolution and high-contrast imaging and thus in the study of circumstellar disks, envelopes and companions.

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