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 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.

scholarly journals Direct characterization of young giant exoplanets at high spectral resolution by coupling SPHERE and CRIRES+

2021 ◽  
Vol 646 ◽  
pp. A150
Author(s):  
G. P. P. L. Otten ◽  
A. Vigan ◽  
E. Muslimov ◽  
M. N’Diaye ◽  
E. Choquet ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
Extrasolar Planets ◽  
Signal To Noise Ratio ◽  
Detection Limits ◽  
Spectral Lines ◽  
High Spectral Resolution ◽  
Contrast Imaging ◽  
High Contrast Imaging ◽  
The Impact

Studies of atmospheres of directly imaged extrasolar planets with high-resolution spectrographs have shown that their characterization is predominantly limited by noise on the stellar halo at the location of the studied exoplanet. An instrumental combination of high-contrast imaging and high spectral resolution that suppresses this noise and resolves the spectral lines can therefore yield higher quality spectra. We study the performance of the proposed HiRISE fiber coupling between the direct imager SPHERE and the spectrograph CRIRES+ at the Very Large Telescope for spectral characterization of directly imaged planets. Using end-to-end simulations of HiRISE we determine the signal-to-noise ratio (S/N) of the detection of molecular species for known extrasolar planets in H and K bands, and compare them to CRIRES+. We investigate the ultimate detection limits of HiRISE as a function of stellar magnitude, and we quantify the impact of different coronagraphs and of the system transmission. We find that HiRISE largely outperforms CRIRES+ for companions around bright hosts like β Pictoris or 51 Eridani. For an H = 3.5 host, we observe a gain of a factor of up to 16 in observing time with HiRISE to reach the same S/N on a companion at 200 mas. More generally, HiRISE provides better performance than CRIRES+ in 2 h integration times between 50 and 350 mas for hosts with H < 8.5 and between 50 and 700 mas for H < 7. For fainter hosts like PDS 70 and HIP 65426, no significant improvements are observed. We find that using no coronagraph yields the best S/N when characterizing known exoplanets due to higher transmission and fiber-based starlight suppression. We demonstrate that the overall transmission of the system is in fact the main driver of performance. Finally, we show that HiRISE outperforms the best detection limits of SPHERE for bright stars, opening major possibilities for the characterization of future planetary companions detected by other techniques.

scholarly journals Astrometric and photometric accuracies in high contrast imaging: The SPHERE speckle calibration tool (SpeCal)

2018 ◽  
Vol 615 ◽  
pp. A92 ◽  
Author(s):  
R. Galicher ◽  
A. Boccaletti ◽  
D. Mesa ◽  
P. Delorme ◽  
R. Gratton ◽  
...  
Keyword(s):  
Circumstellar Disks ◽  
Observation Time ◽  
High Contrast ◽  
Large Telescope ◽  
Contrast Imaging ◽  
High Contrast Imaging ◽  
Very Large Telescope ◽  
User Friendly ◽  
Calibration Tool

Context. The consortium of the Spectro-Polarimetric High-contrast Exoplanet REsearch installed at the Very Large Telescope (SPHERE/VLT) has been operating its guaranteed observation time (260 nights over five years) since February 2015. The main part of this time (200 nights) is dedicated to the detection and characterization of young and giant exoplanets on wide orbits. Aims. The large amount of data must be uniformly processed so that accurate and homogeneous measurements of photometry and astrometry can be obtained for any source in the field. Methods. To complement the European Southern Observatory pipeline, the SPHERE consortium developed a dedicated piece of software to process the data. First, the software corrects for instrumental artifacts. Then, it uses the speckle calibration tool (SpeCal) to minimize the stellar light halo that prevents us from detecting faint sources like exoplanets or circumstellar disks. SpeCal is meant to extract the astrometry and photometry of detected point-like sources (exoplanets, brown dwarfs, or background sources). SpeCal was intensively tested to ensure the consistency of all reduced images (cADI, Loci, TLoci, PCA, and others) for any SPHERE observing strategy (ADI, SDI, ASDI as well as the accuracy of the astrometry and photometry of detected point-like sources. Results. SpeCal is robust, user friendly, and efficient at detecting and characterizing point-like sources in high contrast images. It is used to process all SPHERE data systematically, and its outputs have been used for most of the SPHERE consortium papers to date. SpeCal is also a useful framework to compare different algorithms using various sets of data (different observing modes and conditions). Finally, our tests show that the extracted astrometry and photometry are accurate and not biased.

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