- ID:
- ivo://CDS.VizieR/J/ApJ/749/15
- Title:
- The Kepler-20 planetary system
- Short Name:
- J/ApJ/749/15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the discovery of the Kepler-20 planetary system, which we initially identified through the detection of five distinct periodic transit signals in the Kepler light curve of the host star 2MASS J19104752+4220194. From high-resolution spectroscopy of the star, we find a stellar effective temperature T_eff_= 5455+/-100 K, a metallicity of [Fe/H] = 0.01+/-0.04, and a surface gravity of log g = 4.4+/-0.1. We combine these estimates with an estimate of the stellar density derived from the transit light curves to deduce a stellar mass of M_*_ = 0.912+/-0.034 M_{sun}_and a stellar radius of R_*_ = 0.944^+0.060^_-0.095_R_{sun}_. For three of the transit signals, we demonstrate that our results strongly disfavor the possibility that these result from astrophysical false positives. We determine the orbital periods and physical radii of the three confirmed planets to be 3.70 days and 1.91^+0.12^_-0.21_R_{earth}_ for Kepler-20b, 10.85 days and 3.07^+0.20^_-0.31_R_{earth}_ for Kepler-20c, and 77.61 days and 2.75^+0.17^_-0.30_R_{earth}_ for Kepler-20d. From multi-epoch radial velocities, we determine the masses of Kepler-20b and Kepler-20c to be 8.7+/-2.2 M_{earth}_ and 16.1 +/-3.5 M_{earth}_, respectively, and we place an upper limit on the mass of Kepler-20d of 20.1 M_{earth}_(2{sigma}).
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Search Results
18932. The KepVIM catalog
- ID:
- ivo://CDS.VizieR/J/ApJS/224/19
- Title:
- The KepVIM catalog
- Short Name:
- J/ApJS/224/19
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Variability-induced motion (VIM) is an observable effect in simultaneous astrometric and photometric measurements caused by brightness variation in one of the components of a double source or blended image, which manifests itself as a strongly correlated shift of the optical photocenter. We have processed the entire collection of Kepler long-cadence light curve data, looking for correlated signals in astrometry and photometry on the time basis of a quarter-year. Limiting the VIM correlation coefficient to 0.3, VIM events are detected for 129525 Kepler stars in at least one quarter. Of 7305 Kepler objects of interest, 4440 are detected as VIM at least once. Known variable stars and resolved double stars have elevated rates of VIM detection. Confident VIM occurrences are found for stars with suggested superflare events, indicating possible signal contamination. We present a complete catalog of all quarterly VIM detections. This catalog should be checked for such astrophysically significant events as transits of exoplanets, new eclipsing stars, and superflares of solar-type stars.
- ID:
- ivo://CDS.VizieR/J/AJ/153/140
- Title:
- The kinematics of the C II {lambda}6578 line in PNe
- Short Name:
- J/AJ/153/140
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present spectroscopic observations of the C II {lambda}6578 permitted line for 83 lines of sight in 76 planetary nebulae at high spectral resolution, most of them obtained with the Manchester Echelle Spectrograph on the 2.1 m telescope at the Observatorio Astronomico Nacional on the Sierra San Pedro Martir. We study the kinematics of the C II {lambda}6578 permitted line with respect to other permitted and collisionally excited lines. Statistically, we find that the kinematics of the C II {lambda}6578 line are not those expected if this line arises from the recombination of C^2+^ ions or the fluorescence of C^+^ ions in ionization equilibrium in a chemically homogeneous nebular plasma, but instead its kinematics are those appropriate for a volume more internal than expected. The planetary nebulae in this sample have well-defined morphology and are restricted to a limited range in H{alpha} line widths (no large values) compared to their counterparts in the Milky Way bulge; both these features could be interpreted as the result of young nebular shells, an inference that is also supported by nebular modeling. Concerning the long-standing discrepancy between chemical abundances inferred from permitted and collisionally excited emission lines in photoionized nebulae, our results imply that multiple plasma components occur commonly in planetary nebulae.
- ID:
- ivo://CDS.VizieR/J/AJ/155/186
- Title:
- The KMTNet/K2-C9 (Kepler) Data Release
- Short Name:
- J/AJ/155/186
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Korea Microlensing Telescope Network (KMTNet) light curves for microlensing-event candidates in the Kepler K2 C9 field having peaks within three effective timescales of the Kepler observations. These include 181 "clear microlensing" and 84 "possible microlensing" events found by the KMTNet event finder, plus 56 other events found by OGLE and/or MOA that were not found by KMTNet. All data for the first two classes are immediately available for public use without restriction.
18935. The 2LAC catalog
- ID:
- ivo://CDS.VizieR/J/ApJ/743/171
- Title:
- The 2LAC catalog
- Short Name:
- J/ApJ/743/171
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The second catalog of active galactic nuclei (AGNs) detected by the Fermi Large Area Telescope (LAT) in two years of scientific operation is presented. The second LAT AGN catalog (2LAC) includes 1017 {gamma}-ray sources located at high Galactic latitudes (|b|>10{deg}) that are detected with a test statistic (TS) greater than 25 and associated statistically with AGNs. However, some of these are affected by analysis issues and some are associated with multiple AGNs. Consequently, we define a Clean Sample which includes 886 AGNs, comprising 395 BL Lacertae objects (BL Lac objects), 310 flat-spectrum radio quasars (FSRQs), 157 candidate blazars of unknown type (i.e., with broadband blazar characteristics but with no optical spectral measurement yet), 8 misaligned AGNs, 4 narrow-line Seyfert 1 (NLS1s), 10 AGNs of other types, and 2 starburst galaxies. Where possible, the blazars have been further classified based on their spectral energy distributions (SEDs) as archival radio, optical, and X-ray data permit. While almost all FSRQs have a synchrotron-peak frequency <10^14^Hz, about half of the BL Lac objects have a synchrotron-peak frequency >10^15^Hz. The 2LAC represents a significant improvement relative to the first LAT AGN catalog (1LAC), with 52% more associated sources. The full characterization of the newly detected sources will require more broadband data. Various properties, such as {gamma}-ray fluxes and photon power-law spectral indices, redshifts, {gamma}-ray luminosities, variability, and archival radio luminosities and their correlations are presented and discussed for the different blazar classes. The general trends observed in 1LAC are confirmed.
- ID:
- ivo://CDS.VizieR/J/A+A/357/1001
- Title:
- The {lambda}-Orionis ring in CO
- Short Name:
- J/A+A/357/1001
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The table shows clump parameters for 130 peaks in CO(J=1->0) emission detected in the Lambda-Orionis ring in the survey of Lang et al. (1998PASA...15...70L). The clumps were isolated using the Clumpfind algorithm of Williams et al. (1994, Cat. <J/ApJ/428/693>). They are ordered and labelled according to the relative brightness of the peak temperatures within them, so clump 1 contains the emission maximum, but not necessarily the maximum W(CO) or largest mass.
18937. The large TNO 2002 TC302
- ID:
- ivo://CDS.VizieR/J/A+A/639/A134
- Title:
- The large TNO 2002 TC302
- Short Name:
- J/A+A/639/A134
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- On 28th January 2018, the large Trans-Neptunian Object 2002 TC_302_ occulted a m_v_~15.3 star with designation 593-005847 in the UCAC4 stellar catalog, corresponding to Gaia source 130957813463146112. Twelve positive occultation chords were obtained from Italy, France, Slovenia and Switzerland. Also, four negative detections were obtained near the north and south limbs. This represents the best observed stellar occultation by a TNO other than Pluto in terms of the number of chords published thus far. From the twelve chords, an accurate elliptical fit to the instantaneous projection of the body can be obtained, compatible with the near misses. The resulting ellipse has major and minor axes of 543+/-18km and 460+/-11km, respectively, with a position angle of 3+/-1 degrees for the minor axis. This information, combined with rotational light curves obtained with the 1.5-m telescope at Sierra Nevada Observatory and the 1.23-m telescope at Calar Alto observatory, allows us to derive possible three-dimensional shapes and density estimations for the body based on hydrostatic equilibrium assumptions. The effective diameter in equivalent area is around 84km smaller than the radiometrically derived diameter using thermal data from Herschel and Spitzer Space Telescopes. This might indicate the existence of an unresolved satellite of up to ~300km in diameter, to account for all the thermal flux, although the occultation and thermal diameters are compatible within their error bars given the considerable uncertainty of the thermal results. The existence of a potential satellite also appears to be consistent with other ground-based data presented here. From the effective occultation diameter combined with absolute magnitude measurements we derive a geometric albedo of 0.147+/-0.005, which would be somewhat smaller if 2002 TC_302_ has a satellite. The best occultation light curves do not show any signs of ring features or any signatures of a global atmosphere.
- ID:
- ivo://CDS.VizieR/J/AJ/156/286
- Title:
- The LEECH exoplanet imaging survey
- Short Name:
- J/AJ/156/286
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of the largest L' (3.8 {mu}m) direct imaging survey for exoplanets to date, the Large Binocular Telescope Interferometer Exozodi Exoplanet Common Hunt (LEECH). We observed 98 stars with spectral types from B to M. Cool planets emit a larger share of their flux in L' compared to shorter wavelengths, affording LEECH an advantage in detecting low-mass, old, and cold-start giant planets. We emphasize proximity over youth in our target selection, probing physical separations smaller than other direct imaging surveys. For FGK stars, LEECH outperforms many previous studies, placing tighter constraints on the hot-start planet occurrence frequency interior to ~20 au. For less luminous, cold-start planets, LEECH provides the best constraints on giant-planet frequency interior to ~20 au around FGK stars. Direct imaging survey results depend sensitively on both the choice of evolutionary model (e.g., hot- or cold-start) and assumptions (explicit or implicit) about the shape of the underlying planet distribution, in particular its radial extent. Artificially low limits on the planet occurrence frequency can be derived when the shape of the planet distribution is assumed to extend to very large separations, well beyond typical protoplanetary dust-disk radii (~<50 au), and when hot-start models are used exclusively. We place a conservative upper limit on the planet occurrence frequency using cold-start models and planetary population distributions that do not extend beyond typical protoplanetary dust-disk radii. We find that ~<90% of FGK systems can host a 7-10 M_Jup_ planet from 5 to 50 au. This limit leaves open the possibility that planets in this range are common.
18939. The LF Survey
- ID:
- ivo://CDS.VizieR/II/221A
- Title:
- The LF Survey
- Short Name:
- II/221A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The LF program was initiated at the Warner and Swasey Observatory by S.W. McCuskey for studies of the variations of the stellar luminosity function (LF) in the Milky Way. The program originally presented in a paper of July 1947 (1947ApJ...106....1M), proposes an observation of selected Milky Way regions with the 24-36-inch Schmidt telescope of the Warner and Swasey Observatory down to mpg=12.25; the observations result in spectral classification, photographic and photored magnitudes of a large number of stars. The original catalogues contain annotated charts of the studied regions, and tables with the spectral types and magnitudes. The catalog included here is a compilation of 13 publications of this program corresponding to the fields LF1 to LF9 (detailed references in the "References" section below). It was prepared by Brian Skiff (Lowell Observatory) over the period 1994-2003, and includes the original data (with the exception of the "red index" colors too noisy to be of use), with cross-identifications to modern catalogues like the GSC (I/254) that give accurate J2000 positions; he also added extensive notes.
- ID:
- ivo://CDS.VizieR/J/ApJS/185/156
- Title:
- The Lick AGN monitoring project
- Short Name:
- J/ApJS/185/156
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Lick AGN Monitoring Project targeted 13 nearby Seyfert 1 galaxies with the intent of measuring the masses of their central black holes using reverberation mapping. The sample includes 12 galaxies selected to have black holes with masses roughly in the range 10^6^-10^7^M_{sun}_, as well as the well-studied active galactic nucleus (AGN) NGC 5548. In conjunction with a spectroscopic monitoring campaign, we obtained broadband B and V images on most nights from 2008 February through 2008 May. The imaging observations were carried out by four telescopes: the 0.76m Katzman Automatic Imaging Telescope, the 2m Multicolor Active Galactic Nuclei Monitoring telescope, the Palomar 60 inch (1.5m) telescope, and the 0.80m Tenagra II telescope. Having well-sampled light curves over the course of a few months is useful for obtaining the broad-line reverberation lag and black hole mass, and also allows us to examine the characteristics of the continuum variability. In this paper, we discuss the observational methods and the photometric measurements, and present the AGN continuum light curves. We measure various variability characteristics of each of the light curves. We do not detect any evidence for a time lag between the B- and V-band variations, and we do not find significant color variations for the AGNs in our sample.