Coronal X-ray emission and planetary irradiation in HD 209458
نویسندگان
چکیده
منابع مشابه
HD 209458 planetary transits from Hipparcos photometry ?
During its 39-month mission, Hipparcos observed the star HD 209458 on 89 occasions. Five of these observations are shown to correspond to epochs of planetary transits, with a 2.3 ± 0.4% mean decrease of flux in the Hp band being observed during the transits. As a result of the long temporal baseline of more than 8 years between the Hipparcos and radial velocity measurements, an accurate orbital...
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We report a spectroscopic orbit with period P=3.52433+/-0.00027 days for the planetary companion that transits the solar-type star HD 209458. For the metallicity, mass, and radius of the star, we derive [Fe/H&sqbr0;=0.00+/-0.02, M*=1.1+/-0.1 M middle dot in circle, and R*=1.2+/-0.1 R middle dot in circle. This is based on a new analysis of the iron lines in our HIRES template spectrum and also ...
متن کاملMulticolor Observations of a Planetary Transit of Hd 209458
We present BV RIZ photometric observations of HD 209458 during the transit by its planetary companion on UT 1999 November 15 with the University of Hawaii 0.6m and 2.2m telescopes and the High Altitude Observatory STARE telescope. The detailed shape of the transit curve is predicted to vary with color due primarily to the color-dependent limb-darkening of the star, but potentially due as well t...
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We present the data, and modeling and analysis results from the photometric monitoring of five planetary transits of HD 209458 using the Fine Guidance Sensors (FGS) onboard the Hubble Space Telescope (HST). We have now included the output from all four FGS photometers in our data reduction and analysis increasing our S/N over our previous results. We have modeled the transits as an opaque spher...
متن کاملCoronal X-ray emission from an intermediate-age brown dwarf
We report the X-ray detection of the brown dwarf (BD) companion TWA 5B in a ≃ 12 Myr old pre-main sequence binary system. We clearly resolve the faint companion (35 photons) separated from the X-ray luminous primary by 2 arcsec in a Chandra ACIS image. TWA 5B shows a soft X-ray spectrum with a low plasma temperature of only 0.3 keV and a constant flux during the 3 hour observation, of which the...
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ژورنال
عنوان ژورنال: Astronomy & Astrophysics
سال: 2017
ISSN: 0004-6361,1432-0746
DOI: 10.1051/0004-6361/201731408