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- ID:
- ivo://CDS.VizieR/J/other/PSS/210.1
- Title:
- Astrometry of the 5 largest Uranian sat.
- Short Name:
- J/other/PSS/210.
- Date:
- 14 Dec 2021 08:12:44
- Publisher:
- CDS
- Description:
- We present the astrometry of the five largest satellites of Uranus from observations spread over almost three decades with photographic plates and CCDs (mainly), taken at the Pico dos Dias Observatory - Brazil. All positions presented here are obtained from the reanalysis of measurements and images used in previous publications. Reference stars are those from the Gaia Early Data Release 3 (Gaia EDR3) allowing, in addition to a higher accuracy, a larger number of positions of the largest satellites as compared to our previous works. From 1982 to 1987, positions were obtained from photographic plates. From 1989 to 2011, CCDs were used. On average, we obtained {Delta}{alpha}cos{delta}=-11(+/-52) milli-arcseconds and {delta}{delta}=-14 (+/-43) milli-arcseconds for the differences in the sense observation minus ephemerides (DE435+ura111). Comparisons with different ephemerides (DE440, INPOP21a, INPOP19a and NOE-7-2013-MAIN) and results from stellar occultations indicate a possible offset in the (Solar System) barycentric position of the Uranian system barycenter. Overall, our results are useful to improve dynamical models of the Uranian largest satellites as well as the orbit of Uranus.
- ID:
- ivo://CDS.VizieR/J/A+A/584/A72
- Title:
- A transiting rocky planet at 6.5pc from the Sun
- Short Name:
- J/A+A/584/A72
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We know now from radial velocity surveys and transit space missions that planets only a few times more massive than our Earth are frequent around solar-type stars. Fundamental questions about their formation history, physical properties, internal structure, and atmosphere composition are, however, still to be solved. We present here the detection of a system of four low-mass planets around the bright (V=5.5) and close-by (6.5pc) star HD 219134. This is the first result of the Rocky Planet Search programme with HARPS-N on the Telescopio Nazionale Galileo in La Palma. The inner planet orbits the star in 3.0935+/-0.0003-days, on a quasi-circular orbit with a semi-major axis of 0.0382+/-0.0003AU. Spitzer observations allowed us to detect the transit of the planet in front of the star making HD 219134 b the nearest known transiting planet to date.
- ID:
- ivo://CDS.VizieR/J/A+A/576/A66
- Title:
- BD+20 1790 radial velocities and photometry
- Short Name:
- J/A+A/576/A66
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In a previous paper we reported a planetary companion to the young and very active K5Ve star BD+20 1790. This paper aims to more rigorously assess the nature of the radial velocity measurements with an expanded data set and new methods of analysis. We have employed Bayesian methods to simultaneously analyse the radial velocity and activity measurements based on a combined data set that includes new and previously published observations.
- ID:
- ivo://CDS.VizieR/J/ApJ/767/64
- Title:
- Benchmark light curves for exoplanet eclipses
- Short Name:
- J/ApJ/767/64
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Ground-based observations of exoplanet eclipses provide important clues to the planets' atmospheric physics, yet systematics in light curve analyses are not fully understood. It is unknown if measurements suggesting near-infrared flux densities brighter than models predict are real, or artifacts of the analysis processes. We created a large suite of model light curves, using both synthetic and real noise, and tested the common process of light curve modeling and parameter optimization with a Markov Chain Monte Carlo algorithm. With synthetic white noise models, we find that input eclipse signals are generally recovered within 10% accuracy for eclipse depths greater than the noise amplitude, and to smaller depths for higher sampling rates and longer baselines. Red noise models see greater discrepancies between input and measured eclipse signals, often biased in one direction. Finally, we find that in real data, systematic biases result even with a complex model to account for trends, and significant false eclipse signals may appear in a non-Gaussian distribution. To quantify the bias and validate an eclipse measurement, we compare both the planet-hosting star and several of its neighbors to a separately chosen control sample of field stars. Re-examining the Rogers et al. (2009, J/ApJ/707/1707) Ks-band measurement of CoRoT-1b finds an eclipse 3190_-440_^+370^ppm deep centered at {phi}_me_=0.50418_-0.00203_^+0.00197^. Finally, we provide and recommend the use of selected data sets we generated as a benchmark test for eclipse modeling and analysis routines, and propose criteria to verify eclipse detections.
- ID:
- ivo://CDS.VizieR/J/A+A/543/A98
- Title:
- {beta} Gem radial velocity and photometric data
- Short Name:
- J/A+A/543/A98
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Our aim is to use precise radial velocity measurements and photometric data to derive the frequency spacing of the p-mode oscillation spectrum of the planet-hosting star beta Gem. This spacing along with the interferometric radius for this star can then be used to derive an accurate stellar mass.
- ID:
- ivo://CDS.VizieR/J/A+A/542/A18
- Title:
- {beta}Pic Harps radial velocity data
- Short Name:
- J/A+A/542/A18
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The {beta} Pictoris system with its debris disk and a massive giant planet orbiting at ~=9AU represents an ideal laboratory for studying giant planet formation and evolution as well as planet-disk interactions. {beta} Pic b can also help in testing brightness-mass relations at young ages. Other planets, yet undetected, may of course be present in the system. We aim at directly constraining the mass of {beta} Pic b and at searching for additional jovian planets on orbits closer than typically 2AU.
- ID:
- ivo://CDS.VizieR/J/A+A/607/A25
- Title:
- beta Pic HARPS spectrum
- Short Name:
- J/A+A/607/A25
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The young planetary system beta Pictoris is surrounded by a circumstellar disk of dust and gas. Because both dust and gas have a lifetime shorter than the system age, they need to be replenished continuously. The gas composition is partly known, but its location and its origin are still a puzzle. The gas source could be the exocomets (or so-called falling and evaporating bodies, FEBs), which are observed as transient features in absorption lines of refractory elements (Mg, Ca, and Fe) when they transit in front of the star at several tens of stellar radii. Nearly 1700 high-resolution spectra of beta Pictoris have been obtained from 2003 to 2015 using the HARPS spectrograph. In these spectra, the circumstellar disk is always detected as a stable component among the numerous variable absorption signatures of transiting exocomets. Summing all the 1700 spectra allowed us to reach a signal-to-noise ratio higher than 1000, which is an unprecedentedly high number for a beta Pictoris spectrum. It revealed many weak Fe I absorption lines of the circumstellar gas in more than ten excited states. These weak lines bring new information on the physical properties of the neutral iron gas in the circumstellar disk. The population of the first excited levels follows a Boltzmann distribution with a slope consistent with a gas temperature of about 1300K; this temperature corresponds to a distance to the star of ~38 R_star_ and implies a turbulence of ksi~0.8km/s.
- ID:
- ivo://CDS.VizieR/J/ApJ/745/19
- Title:
- Binary systems in Taurus-Auriga
- Short Name:
- J/ApJ/745/19
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The past decade has seen a revolution in our understanding of protoplanetary disk evolution and planet formation in single-star systems. However, the majority of solar-type stars form in binary systems, so the impact of binary companions on protoplanetary disks is an important element in our understanding of planet formation. We have compiled a combined multiplicity/disk census of Taurus-Auriga, plus a restricted sample of close binaries in other regions, in order to explore the role of multiplicity in disk evolution. Our results imply that the tidal influence of a close (<=40AU) binary companion significantly hastens the process of protoplanetary disk dispersal, as ~2/3 of all close binaries promptly disperse their disks within <~1Myr after formation. However, prompt disk dispersal only occurs for a small fraction of wide binaries and single stars, with ~80%-90% retaining their disks for at least ~2-3Myr (but rarely for more than ~5Myr). Our new constraints on the disk clearing timescale have significant implications for giant planet formation; most single stars have 3-5Myr within which to form giant planets, whereas most close binary systems would have to form giant planets within <~1Myr. If core accretion is the primary mode for giant planet formation, then gas giants in close binaries should be rare. Conversely, since almost all single stars have a similar period of time within which to form gas giants, their relative rarity in radial velocity (RV) surveys indicates either that the giant planet formation timescale is very well matched to the disk dispersal timescale or that features beyond the disk lifetime set the likelihood of giant planet formation.
- ID:
- ivo://CDS.VizieR/J/AJ/156/207
- Title:
- Brightness of active Ionian volcanoes
- Short Name:
- J/AJ/156/207
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Tidal heating is the major source of heat in the outer solar system. Because of its strong tidal interaction with Jupiter and the other Galilean satellites, Io is incredibly volcanically active. We use the directly measured volcanic activity level of Io's volcanoes as a proxy for surface heat flow and compare it to tidal heating model predictions. Volcanic activity is a better proxy for heat flow than simply the locations of volcanic constructs. We determine the volcanic activity level using three data sets: the Galileo Photopolarimeter Radiometer (PPR), Galileo Near-Infrared Mapping Spectrometer (NIMS), and New Horizons LEISA. We also present a systematic reanalysis of the Galileo NIMS observations to determine the 3.5 {mu}m brightness of 51 active volcanoes. We find that potential differences in volcanic style between high and low latitudes make high-latitude observations unreliable for distinguishing between tidal heating models. Observations of Io's polar areas, such as those by Juno, are necessary to unambiguously understand Io's heat flow. However, all three of the data sets examined show a relative dearth of volcanic brightness near 180 W (anti-Jovian point) and the equator, and the only data set with good observations of the sub-Jovian point (LEISA) also shows a lack of volcanic brightness in that region. These observations are more consistent with the mantle-heating model than the asthenospheric-heating model. Furthermore, all three of the data sets are consistent with fourfold symmetry in longitude and peak heat flow at mid-latitudes, which best matches with the combined heating case of Tackley et al. (2001Icar..149...79T).
