Direct detection of hot extrasolar planets with the VLTI using differential interferometry

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.

Download Full-text

High-order adaptive optics requirements for direct detection of extrasolar planets: Application to the SPHERE instrument

Optics Express ◽

10.1364/oe.14.007515 ◽

2006 ◽

Vol 14 (17) ◽

pp. 7515 ◽

Cited By ~ 95

Author(s):

T. Fusco ◽

G. Rousset ◽

J.-F. Sauvage ◽

C. Petit ◽

J.-L. Beuzit ◽

...

Keyword(s):

Adaptive Optics ◽

Extrasolar Planets ◽

Direct Detection ◽

High Order

Download Full-text

RefPlanets: Search for reflected light from extrasolar planets with SPHERE/ZIMPOL

Astronomy and Astrophysics ◽

10.1051/0004-6361/201936641 ◽

2020 ◽

Vol 634 ◽

pp. A69 ◽

Cited By ~ 1

Author(s):

S. Hunziker ◽

H. M. Schmid ◽

D. Mouillet ◽

J. Milli ◽

A. Zurlo ◽

...

Keyword(s):

Extrasolar Planets ◽

Direct Detection ◽

Speckle Noise ◽

Detection Methods ◽

Integration Time ◽

Light Sources ◽

Post Processing ◽

Photon Noise ◽

Reflected Light ◽

Blind Search

Aims. RefPlanets is a guaranteed time observation programme that uses the Zurich IMaging POLarimeter (ZIMPOL) of Spectro-Polarimetric High-contrast Exoplanet REsearch instrument at the Very Large Telescope to perform a blind search for exoplanets in wavelengths from 600 to 900 nm. The goals of this study are the characterisation of the unprecedented high polarimetic contrast and polarimetric precision capabilities of ZIMPOL for bright targets, the search for polarised reflected light around some of the closest bright stars to the Sun, and potentially the direct detection of an evolved cold exoplanet for the first time. Methods. For our observations of α Cen A and B, Sirius A, Altair, ɛ Eri and τ Ceti we used the polarimetricdifferential imaging (PDI) mode of ZIMPOL which removes the speckle noise down to the photon noise limit for angular separations ≿0.6′′. We describe some of the instrumental effects that dominate the noise for smaller separations and explain how to remove these additional noise effects in post-processing. We then combine PDI with angular differential imaging as a final layer of post-processing to further improve the contrast limits of our data at these separations. Results. For good observing conditions we achieve polarimetric contrast limits of 15.0–16.3 mag at the effective inner working angle of ~0.13′′, 16.3–18.3 mag at 0.5′′, and 18.8–20.4 mag at 1.5′′. The contrast limits closer in (≾0.6′′) display a significant dependence on observing conditions, while in the photon-noise-dominated regime (≿0.6′′) the limits mainly depend on the brightness of the star and the total integration time. We compare our results with contrast limits from other surveys and review the exoplanet detection limits obtained with different detection methods. For all our targets we achieve unprecedented contrast limits. Despite the high polarimetric contrasts we are not able to find any additional companions or extended polarised light sources in the data obtained so far.

Download Full-text