- ID:
- ivo://CDS.VizieR/J/A+A/437/1147
- Title:
- Amalthea and Thebe CCD astrometric obs.
- Short Name:
- J/A+A/437/1147
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents the results of observations of Jupiter's satellites Amalthea and Thebe made in 1995, 1996 and 2001 at the Laboratorio Nacional de Astrofisica (LNA), Brazil. The observations were made in visible light wavelengths with a 1.6m reflector telescope and the light of Jupiter was covered by a mask placed near the CCD surface. The already published positions for 1995, whose astrometric reduction used the Galilean satellites, are now reduced using the stars in the CCD fields like the new positions of 1996 and 2001. The 2001 data are much better than those obtained in 1995, and that those from 1996 show large residuals. Considering the 310 frames observed, the mean residual is about 0.01" and the standard deviation is about 0.15".
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/143/39
- Title:
- Analysis of hot Jupiters in Kepler Q2
- Short Name:
- J/AJ/143/39
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper, we present the results of searching the Kepler Q2 public data set for the secondary eclipses of 76 hot Jupiter planet candidates from the list of 1235 candidates published by Borucki et al., 2011, Cat. J/ApJ/736/19. This search has been performed by modeling both the Kepler pre-search data conditioned light curves and new light curves produced via our own photometric pipeline. We derive new stellar and planetary parameters for each system, while calculating robust errors for both. We find 16 systems with 1{sigma}-2{sigma}, 14 systems with 2{sigma}-3{sigma}, and 6 systems with >3{sigma} confidence level secondary eclipse detections in at least one light curve produced via the Kepler pre-search data conditioned light curve or our own pipeline; however, results can vary depending on the light curve modeled and whether eccentricity is allowed to vary or not. We estimate false alarm probabilities of 31%, 10%, and 6% for the 1{sigma}-2{sigma}, 2{sigma}-3{sigma}, and >3{sigma} confidence intervals, respectively.
- ID:
- ivo://CDS.VizieR/J/ApJ/806/248
- Title:
- AO imaging of KOIs with gas giant planets
- Short Name:
- J/ApJ/806/248
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- As hundreds of gas giant planets have been discovered, we study how these planets form and evolve in different stellar environments, specifically in multiple stellar systems. In such systems, stellar companions may have a profound influence on gas giant planet formation and evolution via several dynamical effects such as truncation and perturbation. We select 84 Kepler Objects of Interest (KOIs) with gas giant planet candidates. We obtain high-angular resolution images using telescopes with adaptive optics (AO) systems. Together with the AO data, we use archival radial velocity data and dynamical analysis to constrain the presence of stellar companions. We detect 59 stellar companions around 40 KOIs for which we develop methods of testing their physical association. These methods are based on color information and galactic stellar population statistics. We find evidence of suppressive planet formation within 20 AU by comparing stellar multiplicity. The stellar multiplicity rate (MR) for planet host stars is 0_-0_^+5^% within 20 AU. In comparison, the stellar MR is 18%+/-2% for the control sample, i.e., field stars in the solar neighborhood. The stellar MR for planet host stars is 34%+/-8% for separations between 20 and 200 AU, which is higher than the control sample at 12%+/-2%. Beyond 200 AU, stellar MRs are comparable between planet host stars and the control sample. We discuss the implications of the results on gas giant planet formation and evolution.
- ID:
- ivo://CDS.VizieR/J/ApJ/767/127
- Title:
- Asteroseismic solutions for 77 Kepler stars
- Short Name:
- J/ApJ/767/127
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have used asteroseismology to determine fundamental properties for 66 Kepler planet-candidate host stars, with typical uncertainties of 3% and 7% in radius and mass, respectively. The results include new asteroseismic solutions for four host stars with confirmed planets (Kepler-4, Kepler-14, Kepler-23 and Kepler-25) and increase the total number of Kepler host stars with asteroseismic solutions to 77. A comparison with stellar properties in the planet-candidate catalog by Batalha et al. (2013, J/ApJS/204/24) shows that radii for subgiants and giants obtained from spectroscopic follow-up are systematically too low by up to a factor of 1.5, while the properties for unevolved stars are in good agreement. We furthermore apply asteroseismology to confirm that a large majority of cool main-sequence hosts are indeed dwarfs and not misclassified giants. Using the revised stellar properties, we recalculate the radii for 107 planet candidates in our sample, and comment on candidates for which the radii change from a previously giant-planet/brown-dwarf/stellar regime to a sub-Jupiter size or vice versa. A comparison of stellar densities from asteroseismology with densities derived from transit models in Batalha et al. assuming circular orbits shows significant disagreement for more than half of the sample due to systematics in the modeled impact parameters or due to planet candidates that may be in eccentric orbits. Finally, we investigate tentative correlations between host-star masses and planet-candidate radii, orbital periods, and multiplicity, but caution that these results may be influenced by the small sample size and detection biases.
- ID:
- ivo://CDS.VizieR/J/A+A/545/A144
- Title:
- Astrometric observations of Deimos
- Short Name:
- J/A+A/545/A144
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Between July 2005 and July 2011 Mars Express performed 50 Deimos approaches. 156 SRC images were acquired and used for astrometric (positional) measurements of the small Martian satellite. For this study, we have developed a new technique, where the center-of-figure of the odd-shaped Deimos was determined by fitting the predicted to the observed satellite limb. The prediction of the limb was made based on the moon's known shape model. The camera pointing was verified and corrected by means of background star observations. We obtained a set of spacecraft- centered Deimos coordinates with accuracies between 0.6 and 3.6km (1 sigma). Comparisons with current orbit models indicate that Deimos is ahead or falling behind its predicted position along its track by as much as +3.7km or -4.4km, respectively, depending on the chosen model. Our data may be used to improve the orbit models of the satellite.
- ID:
- ivo://CDS.VizieR/J/A+A/580/A28
- Title:
- Astrometric observations of Phobos
- Short Name:
- J/A+A/580/A28
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Mars Express (MEX) carried out 74 Phobos flybys at distances between 669 and 5579km from April 2008 to August 2011. Images taken with the Super Resolution Channel (SRC) were used to determine the Martian moon's spacecraft-centered right ascension and declination. Image positions of Phobos were measured using the control point and limb fit measurement techniques. Camera pointing and pointing drift were controlled by means of background star observations that were compared to the corresponding positions from the Tycho-2 catalog. Blurred and noisy images were restored by applying an image-based point spread function in a Richardson-Lucy deconvolution. Altogether, we provide 158 astrometric observations of Phobos with estimated uncertainties between 0.224 and 3.405km circular about the direction to the satellite. Control point measurements yield more accurate results than limb fit observations.
- ID:
- ivo://CDS.VizieR/J/A+A/572/A104
- Title:
- Astrometric obs. of Phobos and Deimos in 1971
- Short Name:
- J/A+A/572/A104
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Accurate positional measurements of planets and satellites are used to improve our knowledge of their dynamics and to infer the accuracy of planet and satellite ephemerides. In the framework of the FP7 ESPaCE project, we provide positions of Mars, Phobos and Deimos taken with the U.S. Naval Observatory 26-inch refractor during the 1971 opposition of the planet. These plates were measured with the digitizer of the Royal Observatory of Belgium and reduced through an optimal process that includes image, instrumental and spherical corrections to provide the most accurate data.
- ID:
- ivo://CDS.VizieR/J/A+A/383/1054
- Title:
- Astrometry of Pluto and Saturn in 1995-2001
- Short Name:
- J/A+A/383/1054
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this work, we publish astrometric positions of Pluto and satellites of Saturn obtained with the Bordeaux and Valinhos CCD meridian circles. These observations are used to test the DE403 and DE405 ephemerides.
- 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/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.
