- ID:
- ivo://CDS.VizieR/J/A+A/646/A157
- Title:
- HD 108236 CHEOPS light curves
- Short Name:
- J/A+A/646/A157
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The detection of a super-Earth and three mini-Neptunes transiting the bright (V=9.2mag) star HD108236 (also known as TOI-1233) was recently reported on the basis of TESS and ground-based light curves. We perform a first characterisation of the HD108236 planetary system through high-precision CHEOPS photometry and improve the transit ephemerides and system parameters. We characterise the host star through spectroscopic analysis and derive the radius with the infrared flux method.We constrain the stellar mass and age by combining the results obtained from two sets of stellar evolutionary tracks. We analyse the available TESS light curves and one CHEOPS transit light curve for each known planet in the system. We find that HD108236 is a Sun-like star with R*=0.877+/-0.008R_{sun}_, M*=0.869^+0.050^_0.048_M_{sun}_, and an age of 6.7^+4.0^_5.1_Gyr. We report the serendipitous detection of an additional planet, HD108236 f, in one of the CHEOPS light curves. For this planet, the combined analysis of the TESS and CHEOPS light curves leads to a tentative orbital period of about 29.5days. From the light curve analysis, we obtain radii of 1.615+/-0.051, 2.071+/-0.052, 2.539^+0.062^_0.065_, 3.083+/-0.052, and 2.017^+0.052^+0.057_R_{Earth}_ for planets HD108236 b to HD108236 f, respectively. These values are in agreement with previous TESS-based estimates, but with an improved precision of about a factor of two. We perform a stability analysis of the system, concluding that the planetary orbits most likely have eccentricities smaller than 0.1. We also employ a planetary atmospheric evolution framework to constrain the masses of the five planets, concluding that HD108236 b and HD108236 c should have an Earth-like density, while the outer planets should host a low mean molecular weight envelope. The detection of the fifth planet makes HD108236 the third system brighter than V=10mag to host more than four transiting planets. The longer time span enables us to significantly improve the orbital ephemerides such that the uncertainty on the transit times will be of the order of minutes for the years to come. A comparison of the results obtained from the TESS and CHEOPS light curves indicates that for a V~9mag solar-like star and a transit signal of 500ppm, one CHEOPS transit light curve ensures the same level of photometric precision as eight TESS transits combined, although this conclusion depends on the length and position of the gaps in the light curve.
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- ID:
- ivo://CDS.VizieR/J/A+A/606/A125
- Title:
- HD163296 DCO+, DCN and N_2_D+ data cubes
- Short Name:
- J/A+A/606/A125
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Deuterium fractionation has been used to study the thermal history of prestellar environments. Their formation pathways trace different regions of the disk and may shed light into the physical structure of the disk, including locations of important features for planetary formation. We aim to constrain the radial extent of the main deuterated species; we are particularly interested in spatially characterizing the high and low temperature pathways for enhancing deuteration of these species. We observed the disk surrounding the Herbig Ae star HD 163296 using ALMA in Band 6 and obtained resolved spectral imaging data of DCO^+^ (J=3-2), DCN (J=3-2) and N_2_D^+^ (J=3-2) with synthesized beam sizes of 0.53"x0.42", 0.53"x0.42", and 0.50"x0.39", respectively. We adopted a physical model of the disk from the literature and use the 3D radiative transfer code LIME to estimate an excitation temperature profile for our detected lines. We modeled the radial emission profiles of DCO^+^, DCN, and N_2_D^+^, assuming their emission is optically thin, using a parametric model of their abundances and our excitation temperature estimates.
- ID:
- ivo://CDS.VizieR/J/A+A/635/A19
- Title:
- HD 117214 debris disk polarization images
- Short Name:
- J/A+A/635/A19
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Young stars with debris disks are the most promising targets for an exoplanet search because debris indicate a successful formation of planetary bodies. Debris disks can be shaped by planets into ring structures that give valuable indications on the presence and location of planets in the disk. We performed observations of the Sco-Cen F star HD 117214 to search for planetary companions and to characterize the debris disk structure. HD 117214 was observed with the SPHERE subsystems IRDIS, IFS, and ZIMPOL at optical and near-IR wavelengths using angular and polarimetric differential imaging techniques. This provided the first images of scattered light from the debris disk with the highest spatial resolution of 25mas and an inner working angle <0.1". With the observations with IRDIS and IFS we derived detection limits for substellar companions. The geometrical parameters of the detected disk were constrained by fitting 3D models for the scattering of an optically thin dust disk. Investigating the possible origin of the disk gap, we introduced putative planets therein and modeled the planet-disk and planet-planet dynamical interactions. The obtained planetary architectures were compared with the detection limit curves. The debris disk has an axisymmetric ring structure with a radius of 0.42(+/-0.01)" or ~45au and an inclination of 71(+/-2.5){deg} and exhibits a 0.4" (~40au) wide inner cavity. From the polarimetric data, we derive a polarized flux contrast for the disk of (Fpol)_disk_/F*=(3.1+/-1.2)x10^-4^ in the RI band. The fractional scattered polarized flux of the disk is eight times lower than the fractional IR flux excess. This ratio is similar to the one obtained for the debris disk HIP 79977, indicating that dust radiation properties are similar for these two disks. Inside the disk cavity we achieve high-sensitivity limits on planetary companions with a mass down to ~4M_J_ at projected radial separations between 0.2" and 0.4". We can exclude stellar companions at a radial separation larger than 75mas from the star.
- ID:
- ivo://CDS.VizieR/J/A+A/650/A59
- Title:
- HD 142527 disk 13CO and C18O images
- Short Name:
- J/A+A/650/A59
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- Vortices are one of the most promising mechanisms to locally concentrate millimeter dust grains and allow the formation of planetesimals through gravitational collapse. The outer disk around the binary system HD 142527 is known for its large horseshoe structure with azimuthal contrasts of ~3-5 in the gas surface density and of ~50 in the dust. Using ^13^CO and C^18^O J=3-2 transition lines, we detect kinematic deviations to the Keplerian rotation, which are consistent with the presence of a large vortex around the dust crescent, as well as a few spirals in the outer regions of the disk. Comparisons with a vortex model suggest velocity deviations up to 350m/s after deprojection compared to the background Keplerian rotation, as well as an extension of +/-40au radially and ~200{deg} azimuthally, yielding an azimuthal-to-radial aspect ratio of ~5. Another alternative for explaining the vortex-like signal implies artificial velocity deviations generated by beam smearing in association with variations of the gas velocity due to gas pressure gradients at the inner and outer edges of the circumbinary disk. The two scenarios are currently difficult to differentiate and, for this purpose, would probably require the use of multiple lines at a higher spatial resolution. The beam smearing effect, due to the finite spatial resolution of the observations and gradients in the line emission, should be common in observations of protoplanetary disks and may lead to misinterpretations of the gas velocity, in particular around ring-like structures.
- ID:
- ivo://CDS.VizieR/IV/27A
- Title:
- HD-DM-GC-HR-HIP-Bayer-Flamsteed Cross Index
- Short Name:
- IV/27A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New Cross Index is constructed on the basis of data analyse of basic catalogs: BSC5 (<V/50>), Hipparcos (<I/196>) and CSI (<IV/9>).The full list of the stars with HD-number and Bayer-Flamsteed designations with later extension of various authors was edited according to printed atlases [1,2,3,4]. Some names of variable stars from these atlases was added to the list. The resulting list was edited after the review and the analyses of star names in catalogue list 'refs.dat'. The DM, GC, HR and HIP numbers were added. The DM numbers were taken from the Henry Draper Catalogue (<III/135>),the GC numbers were taken from General Catalogue of 33342 stars (<I/113>),the HR numbers were taken from BSC5 (<V/50>). Finally the list of proper names of stars was made from information analyses of the atlases [1,2,3,4] and the catalogs BSC5, Hipparcos, CSI and <IV/22>. The right ascensions, declinations and visual magnitudes for all stars were taken from Hipparcos and CSI catalogue if the star has no number in Hipparcos.
- ID:
- ivo://CDS.VizieR/III/182
- Title:
- HDE Charts: positions, proper motions
- Short Name:
- III/182
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- of Paper: The Henry Draper Extension Charts (Cannon et al., 1949), published in the form of finding charts, provide spectral classification for some 87000 stars mostly between 10th and 11th magnitude. This data, being highly valuable, as yet was practically unusable for modern computer-based astronomy. An earlier pilot project (Roeser et al. 1991) demonstrated a possibility to convert this into a star catalogue, using measurements of cartesian coordinates of stars on the charts and positions of the Astrographic Catalogue (AC) for subsequent identification. We present here a final HDEC catalogue comprising accurate positions, proper motions, magnitudes and spectral classes for 86933 stars of the Henry Draper Extension Charts.
- ID:
- ivo://CDS.VizieR/J/AJ/134/321
- Title:
- H{delta} line in globular clusters
- Short Name:
- J/AJ/134/321
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a cautionary study exploring the reliability of the H{delta} line in the integrated spectra of galaxies for determining galaxy ages. Our database consists of the observed integrated spectra of ~120 early-type galaxies, 7 metal-rich globular clusters in M31 and the Galactic globular cluster 47 Tuc, and the open cluster M67. We have measured H{delta} using index definitions designed to assess contamination from the CN molecule in and around H{delta} by choosing combinations of bandpasses that both avoid and include a region of CN molecular lines redward of H{delta}. We find systematic differences in the ages derived from H{delta} measurements among the various definitions when extracting ages from H{delta} in old stellar populations with enhanced CN bands due to nonsolar abundance ratios. We propose that neighboring CN lines have a strong effect on pseudocontinuum and central bandpass levels. For stellar populations that have nonsolar abundance ratios in C and/or N, population synthesis models that do not account for abundance ratio variations cannot accurately reproduce the CN 4216{AA} band, which leads to a corresponding inaccuracy in reproducing the various H{delta} indices. Hence, caution must be used when extracting galaxy ages from the H{delta} line in old stellar populations with significant nonsolar abundance ratios.
- ID:
- ivo://CDS.VizieR/J/ApJ/481/673
- Title:
- HDF flanking fields and related data
- Short Name:
- J/ApJ/481/673
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- File flanking.dat contains Unpublished Catalogue of Galaxies identified by the DEEP Team in the Flanking Fields. This is the source catalogue that Vogt et al. (1997ApJ...479L.121V), Phillips et al. (1997ApJ...489..543P), Guzman et al. (1997ApJ...489..559G), and Mendez & Guzman (1998A&A...333..106M) used to select objects. The photometry in this catalogue was carried out using circular apertures of 3 arcsec diameter, as described by Phillips et al. (1997ApJ...489..543P). These will present small differences (~0.12mag, rms) relative to published values for the sample of 51 compact galaxies that were analysed by Phillips et al. (1997ApJ...489..543P) and Guzman et al. (1997ApJ...489..559G). This is because for the papers, the I(814) magnitudes were recalculated using elliptical apertures to 8 arcsec. The differences should only be significant in the case of galaxies with larger apparent sizes or with elongated shapes.
- ID:
- ivo://CDS.VizieR/J/ApJ/538/29
- Title:
- HDF-N Caltech faint galaxy redshift survey. X.
- Short Name:
- J/ApJ/538/29
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A redshift survey has been carried out in the region of the Hubble Deep Field North using the Low Resolution Imaging Spectrograph (LRIS) at the Keck Observatory. The resulting redshift catalog, which contains 671 entries, is a compendium of our own data together with published LRIS/Keck data.
- ID:
- ivo://CDS.VizieR/J/AJ/121/2895
- Title:
- HDF-N Caltech faint galaxy redshift survey. XIII.
- Short Name:
- J/AJ/121/2895
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We introduce a new empirical function for modeling the spectral energy distributions (SEDs) of galaxies. We apply it to a sample of 590 galaxies in the region of the Hubble Deep Field (HDF) with z<1.5 using multicolor photometry with wide wavelength coverage combined with spectroscopic redshifts from our 93% complete R-selected redshift survey there.