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Article
Two families of exocomets in the β Pictoris system
Statistical analysis of over a thousand spectra of the star β Pictoris reveals that it has two kinds of exocomets circling it: old exhausted comets trapped in mean-motion resonance with a massive planet, and f...
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Article
The origin of hydrogen around HD 209458b
Arising from: M. Holmström et al. Nature 451, 970–972 (2008)10.1038/nature06600; Holmström et al. reply
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Article
An extended upper atmosphere around the extrasolar planet HD209458b
The planet in the system HD209458 is the first one for which repeated transits across the stellar disk have been observed1,2. Together with radial velocity measurements3, this has led to a determination of the pl...
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Chapter
Lyman Gamma Satellites Due to H-H+ Collisions: Application to FUSE Observations of Hot White Dwarfs
New theoretical calculations of Lyman 7 profiles perturbed by protons allow us to identificate a large feature near 995 Å in FUSE observations of hot white dwarfs. This feature is due to quasi-molecular Lyman ...
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Chapter
Quasi-Molecular Lines in Lyman Wings of Cool DA White Dwarfs; Application to FUSE Observations of G 231–40
We present new theoretical calculations of Lyman β profiles which include perturbations by both neutral hydrogen and protons. They are used to improve theoretical modeling of synthetic spectra for cool DA white d...
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Article
Deficiency of molecular hydrogen in the disk of β Pictoris
Molecular hydrogen (H2) is by far the most abundant material from which stars, protoplanetary disks and giant planets form, but it is difficult to detect directly. Infrared emission lines from H2 have recently be...
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Article
New Observations of Galactic Deuterium
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Chapter and Conference Paper
New Observations of Galactic Deuterium
Observations made with the Interstellar Medium Absorption Profile Spectrograph (IMAPS) on the US-German ORFEUS-SPAS II mission in late 1996 provide the first new measurements of Galactic interstellar atomic de...
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Article
Deuterium Observations in the Galaxy
An accurate measurement of the primordial value of D/H would provide one of the best tests of nucleosynthesis models for the early Universe and the baryon density. Such evaluations have been traditionally made...
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Chapter and Conference Paper
The Two EROS 4k x 8k CCD Mosaic Cameras
We present our new astronomical wide field imager, which consists of two 4k x 8k CCD mosaic cameras allowing simultaneous imaging in two focal planes with different color passbands. Each mosaic is maintained a...
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Chapter and Conference Paper
Deuterium Observations in the Galaxy
An accurate measurement of the primordial value of D/H would provide one of the best tests of nucleosynthesis models for the early Universe and the baryon density. Such evaluations have been traditionally made...
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Article
A high deuterium abundance at redshift z = 0.7
Of the light elements, the primordial abundance of deuterium relative to hydrogen, (D/H)p, provides the most sensitive diagnostic1 for the cosmological mass density parameter, ΩB. Recent high-redshift D/H measure...
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Chapter and Conference Paper
The Interstellar Gas in the Line of Sight to ε Canis Majoris
We analyse Hubble Space Telescope GHRS observations of the interstellar medium in the direction to ε CMa, the strongest EUV source in the sky located 200 pc away in a region deficient in neutral gas. We show that...
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Article
A 20 cm2 CCD mosaic camera for a dark matter search part I : Mechanics, optics and cryogeny
A 20cm 2 CCD mosaic camera has been especially built to search for dark galactic halo objects by the gravitational microlensing effect. The sensitive area is made of 16 edge-bu...
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Article
A 20cm 2 CCD mosaic camera for a dark matter search part II : Electronics, data acquisition and performance
To summarize, the readout and the control system of the CCD mosaic camera are running since December 1991 at the La Silla Observatory (ESO). The overall performance of the camera has been good. About 12000 pic...
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Article
Cometary-like bodies in the protoplanetary disk aroundβ pictoris
Repeated spectroscopic observations ofβ Pictoris have been performed since 1985 and revealed the presence, in many metallic lines likeCa II, Mg II, Fe II, ..., of strong sporadic circumstellar absorption, redshif...
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Article
Inner part observation of theβ pictoris disk
The inner regions of the circumstellar disk aroundβ Pictoris might be dust-free due to a possible planet which may have cleared up dust particles. We present a new observational technique based on the use of an a...
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Chapter and Conference Paper
Cometary-Like Bodies in the Protoplanetary Disk Around β Pictoris
Repeated spectroscopic observations of β Pictoris have been performed since 1985 and revealed the presence, in many metallic lines like Ca II, Mg II, Fe II, …, of strong sporadic circumstellar absorption, reds...
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Chapter and Conference Paper
Inner Part Observation of the β Pictoris Disk
The inner regions of the circumstellar disk around β Pictoris might be dust-free due to a possible planet which may have cleared up dust particles. We present a new observational technique based on the use of ...
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Article
Evidence for gravitational microlensing by dark objects in the Galactic halo
THE flat rotation curves of spiral galaxies, including our own, indicate that
