相关论文: Ground-based Spectroscopy of the Exoplanet XO-2b u…
Spectroscopy during planetary transits is a powerful tool to probe exoplanet atmospheres. We present the near-infrared transit spectroscopy of XO-2b obtained with HST NICMOS. Uniquely for NICMOS transit spectroscopy, a companion star of…
We present two transits of the hot-Jupiter exoplanet XO-2b using the Gran Telescopio Canarias (GTC). The time series observations were performed using long-slit spectroscopy of XO-2 and a nearby reference star with the OSIRIS instrument,…
The transiting hot Jupiter XO-2b is an ideal target for multi-object photometry and spectroscopy as it has a relatively bright ($V$-mag = 11.25) K0V host star (XO-2N) and a large planet-to-star contrast ratio (R$_{p}$/R$_{s}\approx0.015$).…
With the aim of connecting the compositions of stars and planets, we present the abundances of carbon and oxygen, as well as iron and nickel, for the transiting exoplanet host star XO-2N and its wide-separation binary companion XO-2S.…
XO-2 is the first confirmed wide stellar binary system where the almost twin components XO-2N and XO-2S have planets. This stimulated a detailed characterization study of the stellar and planetary components based on new observations. We…
We present Gran Telescopio Canarias (GTC) optical transit narrow-band photometry of the hot-Jupiter exoplanet XO-2b using the OSIRIS instrument. This unique instrument has the capabilities to deliver high cadence narrow-band photometric…
In the past few years, the study of exoplanets has evolved from being pure discovery, then being more exploratory in nature and finally becoming very quantitative. In particular, transmission spectroscopy now allows the study of…
Till date, only a handful exo-atmospheres have been well characterized, mostly by means of the transit method. Data show exoplanet atmospheres to be diverse. However, this is based on a small number of cases. Here we focus our study on the…
The XO project aims at detecting transiting exoplanets around bright stars from the ground using small telescopes. The original configuration of XO (McCullough et al. 2005) has been changed and extended as described here. The instrumental…
The chemical abundances of exoplanet atmospheres may provide valuable information about the bulk compositions, formation pathways, and evolutionary histories of planets. Exoplanets with large, relatively cloud-free atmospheres, and which…
Hydrostatic equilibrium is an excellent approximation for the dense layers of planetary atmospheres where it has been canonically used to interpret transmission spectra of exoplanets. Here we exploit the ability of high-resolution…
Studies of exoplanetary atmospheres have found no definite correlations between observed high altitude aerosols and other system parameters. This could be, in part, because of the lack of homogeneous exoplanet samples for which specific…
We present ten high-precision light curves of four transits in the XO-1 planetary system, obtained using $u$, $g$, $r$, redshifted H$\alpha$, $I$ and $z$ filters. We use these to measure the physical properties, orbital ephemeris, and a…
We obtained over 90 hours of spectroscopic observations of four exoplanetary systems with the Hobby-Eberly Telescope (HET). Observations were taken in transit and out of transit, and we analyzed the differenced spectra---i.e., the…
The Apache Point Survey of Transit Lightcurves of Exoplanets (APOSTLE) observed 10 transits of XO-2b over a period of three years. We present measurements which confirm previous estimates of system parameters like the normalized semi-major…
We estimate flux ratios of the extrasolar planet XO-2b to its host star XO-2 at 3.6, 4.5, 5.8 and 8.0 micron with IRAC on the Spitzer Space Telescope to be 0.00081 +- 0.00017, 0.00098 +- 0.00020, 0.00167 +- 0.00036 and 0.00133 +- 0.00049,…
Recent progress in high-resolution transmission spectroscopy has offered new avenues in which to characterise the atmospheres of transiting exoplanets. High-resolution cross-correlation spectroscopy allows for the unambiguous detection of…
With the rapid developments in the exoplanet field, more and more terrestrial exoplanets are being detected. Characterising their atmospheres using transit observations will become a key datum in the quest for detecting an Earth-like…
Using forward models for representative exoplanet atmospheres and a radiometric instrument model, we have generated synthetic observational data to explore how well the major C- and O-bearing chemical species (CO, CO2, CH4, and H2O),…
Exoplanetary transmission spectroscopy in the near-infrared using Hubble/NICMOS is currently ambiguous because different observational groups claim different results from the same data, depending on their analysis methodologies. Spatial…