ADONIS/ESO in 1994 and 1995 respectively. The data show the bright
equatorial feature on the leading hemisphere (right) and structure
with brightness at high latitudes in the darker hemisphere (left).
From Combes et al. (1997).
List of
all the documentations available on this web site about ADONIS.
Some interesting
links on AO systems all over the world.
Few images
to show you the recent results obtained with ADONIS.
Titan observed with SHARP (Coustenis et al., 1998)
Io, satellite of Jupiter, observed with COMIC (Marchis
et al., 1999)
AG Carinaeobserved with SHARP II+ and coronograph
(D. Le Mignant et al, 1999)
Eta Carinae observed with SHARPII+/Coronograph/Fabry-Perot
Etalon (D. Le Mignant et al, 1999)
Dark Speckle observation with SHARP II+ (Boccaletti
et al., 1999)
HD 100546 dust disk observed with SHARP II+/Coronagraph
(Pantin et al., 1999)
Adaptive optics systems and projects -
Recent results
obtained with ADONIS AO system.
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| Titan's leading and
trailing sides observed with
ADONIS/ESO in 1994 and 1995 respectively. The data show the bright equatorial feature on the leading hemisphere (right) and structure with brightness at high latitudes in the darker hemisphere (left). From Combes et al. (1997). |
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| Titan's leading side taken with ADONIS in 1994
at 2 micron. During the
same year, the Hubble Space Telescope observed Titan near 1 micron at the same longitude. The two images are compared here. The same bright features are observed. The ADONIS data afford a contrast of about 30%, 3 times higher than the HST. Two or three distinct sub-units can be observed within the equatorial bright region. These are compatible with the presence of some relief covered with fresh ice. The surrounding dark areas are attributed to water ice and tholin deposits (Coustenis et al. 1995). |
Io's Leading and Trailing sides observed with COMIC camera
in October 96 .
The bright and famous hot spot called Loki is clearly
visible on the sub-jovian hemisphere (left image). The anti-jovian one
looks completely different with several fainter hot spots which form the
so-called "ring of fire". Before Galileo observations, only a few hot spots
have been detected by groundbased observations (Loki) or with during the
Voyager flyby (86). The majority of the hot spots indicated here, have
been observed by Galileo/NIMS in 1996 (Lopes-Gautier et al. 1997).
These images has been processed using the IDAC deconvolution
method (J. Christou et al. 1998).
References:
Marchis, F., Prange,R., Christou, J.C., First images of Io by Adaptive
Optics, Icarus, to be submitted, 1999
Lopez-Gautier et al., Geophysical Research Letters, vol 24, no. 20,
p. 2439-2442, 1997.
J.C. Christou, F. Marchis, N. Ageorges, D. Bonaccini, F.J. Rigaut (ESO),
Deconvolution of ADONIS adaptive optics images, Astronomical telescopes
and instrumentation (SPIE conference) - Kona, Hawaii USA 20-28 March 1998
AG Carinae nebula observed with and without coronographic device
Click on the images for magnification.
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AG carinae nebula was observed by D.
Le Mignant and A. Chalabaev in March 99 using the SHARPII+ camera and
the coronograph device (mask radius of 1.00'') in J band (left image).
After sky subtraction, a reference star has been substracted to AGCar to
get rid of the wings of the PSF. The intensity betwen the faintest
dust structures and the star maximum is of about 10^5 (total integration
time of 800sec). The light reflected by the dust component around this
star is clearly visible. Fine structures are revealed in the close environnement
of AGCar down to 3arcsec from the star. These ring-like dusty structures
are in agreement with HST/WPC2 observations (ApJ, 448, 788). Thanks to
the high dynamical range achieved by making use of the coronograph, the
dusty structures and the nebula appear with a higher intensity in our image.
As a comparison, we present a SHARPII+ mosaic image (on the right)
in the SW part of the AGCarinae nebula without any coronograph device.
The star was put outside of the camera field-of-view (integration time
of 60sec).In that case, even if adaptive optic technics improves by a factor
5 the FWHM, the observations close to the star are limited by the blinding
wings of the PSF. Note that we did not subtract for the PSF wings. Still,
dusty structures appear in the circumstellar environment down to about
8arcsec.
Eta Carinae nebula started to expand and fom after the giant outbursts of the central star in 1841 and 1890. I observed this object in April 98 with ADONIS. This image is a "true color image", a composite image of 3 images taken at different velocity shift through the Helium 2.0581µm emission line. To detect the faintest features in the nebula, I made use of the ADONIS coronographic mount and a Fabry-Perot etalon (R=1000). The use of the latter allowed to get kinematic informations on the nebula. The former device permitts to get longer integration time, thus increasing the signal to noise ratio over the entire nebula. The size of the nebula is 12"x18". Note that they are wonderful images on the eta car nebula taken with HST on the STScI/NASA image server
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| Fig 1. Long exposure on a binary star (HD 222493)
and after subtraction by a closed reference star.
\Delta(m_k)=4, \rho=0.9'', 600 frames (60 ms/frame), filtre SK. |
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| Fig 2. Same cube of data but processed by an algorithme
of Dark Speckles. The companion appears clearly on the subtracting image.
Dark-speckle improve the detection of faint companion.
See Labeyrie 1995, A & A 298, 544 Boccaletti et al. 1998b A&A SS 133, 395; and his web page for more explanations on this method. |
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The HD 100546 pre-main-sequence star was observed from the 23-24th night
of June 1999.
We used the adaptive optics system ADONIS combined with Sharp camera
to detect the disk in K' band. The seeing had a value of 1.2" in average.
The field of view is 9x9 arcsec. We used the reference stars HD 97218 and
HD 101713 to remove the starlight contribution and reveal the disk. IRAS
and ISO/SWS observations had shown that this star is surrounded by a relatively
dense disk which is likely to be a precusor to Beta Pic-like disks.
The disk extends on a projected size of 3.2 arcsec (corresponding to 320
AU since HD 100546 is located at a distance of 100 pc from the earth) and
is seen with a tilt angle around 45 degrees.
Before the ADONIS system, there was the COMEON+ system
which has a gallery here.