- ID:
- ivo://CDS.VizieR/J/AJ/161/21
- Title:
- 383 KOIs interferometry with WIYN
- Short Name:
- J/AJ/161/21
- Date:
- 09 Mar 2022 22:00:00
- Publisher:
- CDS
- Description:
- The Kepler mission and subsequent ground-based follow-up observations have revealed a number of exoplanet host stars with nearby stellar companions. This study presents speckle observations of 57 Kepler objects of interest (KOIs) that are also double stars, each observed over a 3-8yr period, which has allowed us to track their relative motions with high precision. Measuring the position angle and separation of the companion with respect to the primary can help determine if the pair exhibits common proper motion, indicating it is likely to be a bound binary system. We report on the motions of 34 KOIs that have close stellar companions, three of which are triple stars, for a total of 37 companions studied. Eighteen of the 34 systems are confirmed exoplanet hosts, including one triple star, while four other systems have been subsequently judged to be false positives and twelve are yet to be confirmed as planet hosts. We find that 21 are most likely to be common proper motion pairs, 4 are line-of-sight companions, and 12 are of an uncertain disposition at present. The fraction of the confirmed exoplanet host systems that are common proper motion pairs is approximately 86% in this sample. In this subsample, the planets are exclusively found with periods of less than 110 days, so that in all cases the stellar companion is found at a much larger separation from the planet host star than the planet itself. A preliminary period-radius relation for the confirmed planets in our sample suggests no obvious differences at this stage with the full sample of known exoplanets.
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- ID:
- ivo://CDS.VizieR/J/ApJ/821/47
- Title:
- KOI transit probabilities of multi-planet syst.
- Short Name:
- J/ApJ/821/47
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- NASA's Kepler Space Telescope has successfully discovered thousands of exoplanet candidates using the transit method, including hundreds of stars with multiple transiting planets. In order to estimate the frequency of these valuable systems, it is essential to account for the unique geometric probabilities of detecting multiple transiting extrasolar planets around the same parent star. In order to improve on previous studies that used numerical methods, we have constructed an efficient, semi-analytical algorithm called the Computed Occurrence of Revolving Bodies for the Investigation of Transiting Systems (CORBITS), which, given a collection of conjectured exoplanets orbiting a star, computes the probability that any particular group of exoplanets can be observed to transit. The algorithm applies theorems of elementary differential geometry to compute the areas bounded by circular curves on the surface of a sphere. The implemented algorithm is more accurate and orders of magnitude faster than previous algorithms, based on comparisons with Monte Carlo simulations. We use CORBITS to show that the present solar system would only show a maximum of three transiting planets, but that this varies over time due to dynamical evolution. We also used CORBITS to geometrically debias the period ratio and mutual Hill sphere distributions of Kepler's multi-transiting planet candidates, which results in shifting these distributions toward slightly larger values. In an Appendix, we present additional semi-analytical methods for determining the frequency of exoplanet mutual events, i.e., the geometric probability that two planets will transit each other (planet-planet occultation, relevant to transiting circumbinary planets) and the probability that this transit occurs simultaneously as they transit their star.
- ID:
- ivo://nasa.heasarc/kommersgrb
- Title:
- Kommers et al. (2001) BATSE Non-Triggered Gamma-Ray Burst Catalog
- Short Name:
- Kommers
- Date:
- 27 Sep 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This is the Kommers et al. (2001) Non-Triggered Burst Supplement to the BATSE Gamma-Ray Burst (GRB) Catalog. It contains 873 "non-triggered" GRBs that were detected in a search of the BATSE Archival continuous data recorded between 1991 December 9 and 1997 December 17 for which the BATSE on-board burst trigger was not activated, for example because the burst was too faint to exceed the on-board detection threshold or it occurred while the on-board trigger was disabled for technical reasons. For each burst, the catalog gives an estimated source direction, duration, peak flux, and fluence. This catalog increases the number of GRBs detected using BATSE by 48% during the time period covered by the search. This database table was created at the HEASARC in September 2001 using the authors' file <a href="http://space.mit.edu/BATSE/ntgrb-ascii.html">http://space.mit.edu/BATSE/ntgrb-ascii.html</a> This is a service provided by NASA HEASARC .
- ID:
- ivo://CDS.VizieR/J/ApJ/850/161
- Title:
- Konus-Wind cat. of GRBs with redshifts. I.
- Short Name:
- J/ApJ/850/161
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this catalog, we present the results of a systematic study of gamma-ray bursts (GRBs) with reliable redshift estimates detected in the triggered mode of the Konus-Wind (KW) experiment during the period from 1997 February to 2016 June. The sample consists of 150 GRBs (including 12 short/hard bursts) and represents the largest set of cosmological GRBs studied to date over a broad energy band. From the temporal and spectral analyses of the sample, we provide the burst durations, the spectral lags, the results of spectral fits with two model functions, the total energy fluences, and the peak energy fluxes. Based on the GRB redshifts, which span the range 0.1<=z<=5, we estimate the rest-frame, isotropic-equivalent energy, and peak luminosity. For 32 GRBs with reasonably constrained jet breaks, we provide the collimation- corrected values of the energetics. We consider the behavior of the rest-frame GRB parameters in the hardness-duration and hardness-intensity planes, and confirm the "Amati" and "Yonetoku" relations for Type II GRBs. The correction for the jet collimation does not improve these correlations for the KW sample. We discuss the influence of instrumental selection effects on the GRB parameter distributions and estimate the KW GRB detection horizon, which extends to z~16.6, stressing the importance of GRBs as probes of the early universe. Accounting for the instrumental bias, we estimate the KW GRB luminosity evolution, luminosity and isotropic-energy functions, and the evolution of the GRB formation rate, which are in general agreement with those obtained in previous studies.
- ID:
- ivo://CDS.VizieR/J/ApJS/228/22
- Title:
- Korean VLBI Network Calibrator Survey (KVNCS). I.
- Short Name:
- J/ApJS/228/22
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the catalog of the KVN Calibrator Survey (KVNCS). This first part of the KVNCS is a single-dish radio survey simultaneously conducted at 22 (K band) and 43GHz (Q band) using the Korean VLBI Network (KVN) from 2009 to 2011. A total of 2045 sources are selected from the VLBA Calibrator Survey with an extrapolated flux density limit of 100mJy at the K band. The KVNCS contains 1533 sources in the K band with a flux density limit of 70mJy and 553 sources in the Q band with a flux density limit of 120mJy; it covers the whole sky down to -32.5{deg} in decl. We detected 513 sources simultaneously in the K and Q bands; ~76% of them are flat-spectrum sources (-0.5<={alpha}<=0.5). From the flux-flux relationship, we anticipated that most of the radiation of many of the sources comes from the compact components. The sources listed in the KVNCS therefore are strong candidates for high-frequency VLBI calibrators.
7706. KPD UV-excess objects
- ID:
- ivo://CDS.VizieR/J/ApJS/61/569
- Title:
- KPD UV-excess objects
- Short Name:
- J/ApJS/61/569
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A survey for ultraviolet-excess objects has been performed for over about 1000sq.deg of the Galactic plane. Photographic blue and ultraviolet plates were obtained to select ultraviolet-excess candidates, and spectroscopic observations were used to determine the nature of those objects. Over 70 white dwarfs and subdwarfs were identified from the survey plates, and these objects were analyzed statistically to determine scale heights and space densities. The sample was complete to B=15.3mag, with the space density of white dwarfs for Mv<12.25 equal to 0.72+/-0.25 per 1000pc^3^, slightly higher than that from the Palomar-Green survey. The average absolute magnitude determined for both the subdwarf O and the subdwarf B stars was considerably fainter than previous determinations, while the scale height for the subdwarfs was lower than earlier suggested values. The space density for the subdwarf O stars is about 7x10^-7^pc^-3^, while the value for the subdwarf B stars is about 2x10^-6^pc^-3, both values considerably higher than previous estimates. The space densities can be used to place evolutionary constraints on these objects.
- ID:
- ivo://CDS.VizieR/J/ApJS/246/15
- Title:
- K2 periodic variables in M35 & NGC2158
- Short Name:
- J/ApJS/246/15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of 1143 periodic variables, compiled from our image-subtracted photometric analysis of the K2 Campaign-0 super stamp. This super stamp is centered on the open clusters M35 and NGC2158. Approximately 46% of our periodic variables were previously unreported. Of the catalog variables, we find that 331 are members of M35 and 56 are members of NGC 2158 (P_m_>0.5). Our catalog contains two new transiting exoplanet candidates, both of which orbit field stars. The smaller planet candidate has a radius of 0.35+/-0.04R_J_ and orbits a K dwarf (Kp=15.4mag) with a transit depth of 2.9mmag. The larger planet candidate has a radius of 0.72+/-0.02R_J_ and orbits a late G-type star (Kp=15.7mag) with a transit depth of 2.2mmag. The larger planet candidate may be an unresolved binary or a false alarm. Our catalog includes 44 eclipsing binaries (EBs), including ten new detections. Of the EBs, one is an M35 member and five are NGC 2158 members. Our catalog contains a total of 1097 nontransiting variable stars, including a field {delta} Cepheid exhibiting double mode pulsations, 561 rotational variables, and 251 pulsating variables (primarily {gamma} Doradus and {delta} Scuti types). The periods of our catalog sources range between 43 minutes to 24 days. The known ages of our reported cluster variables will facilitate investigations of a variety of stellar evolutionary processes.
- ID:
- ivo://CDS.VizieR/J/ApJ/836/167
- Title:
- K2 planetary syst. around low-mass stars. I.
- Short Name:
- J/ApJ/836/167
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present near-infrared spectra for 144 candidate planetary systems identified during Campaigns 1-7 of the NASA K2 Mission. The goal of the survey was to characterize planets orbiting low-mass stars, but our Infrared Telescope Facility/SpeX and Palomar/TripleSpec spectroscopic observations revealed that 49% of our targets were actually giant stars or hotter dwarfs reddened by interstellar extinction. For the 72 stars with spectra consistent with classification as cool dwarfs (spectral types K3-M4), we refined their stellar properties by applying empirical relations based on stars with interferometric radius measurements. Although our revised temperatures are generally consistent with those reported in the Ecliptic Plane Input Catalog (EPIC), our revised stellar radii are typically 0.13R_{sun}_ (39%) larger than the EPIC values, which were based on model isochrones that have been shown to underestimate the radii of cool dwarfs. Our improved stellar characterizations will enable more efficient prioritization of K2 targets for follow-up studies.
- ID:
- ivo://CDS.VizieR/J/AJ/154/207
- Title:
- K2 planetary systems orbiting low-mass stars
- Short Name:
- J/AJ/154/207
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We recently used near-infrared spectroscopy to improve the characterization of 76 low-mass stars around which K2 had detected 79 candidate transiting planets. 29 of these worlds were new discoveries that had not previously been published. We calculate the false positive probabilities that the transit-like signals are actually caused by non-planetary astrophysical phenomena and reject five new transit-like events and three previously reported events as false positives. We also statistically validate 17 planets (7 of which were previously unpublished), confirm the earlier validation of 22 planets, and announce 17 newly discovered planet candidates. Revising the properties of the associated planet candidates based on the updated host star characteristics and refitting the transit photometry, we find that our sample contains 21 planets or planet candidates with radii smaller than 1.25 R_{Earth}_, 18 super-Earths (1.25-2 R_{Earth}_), 21 small Neptunes (2-4 R_{Earth}_), three large Neptunes (4-6 R_{Earth}_), and eight giant planets (>6 R_{Earth}_). Most of these planets are highly irradiated, but EPIC 206209135.04 (K2-72e, 1.29_-0.13_^+0.14^ R_{Earth}_), EPIC 211988320.01 (R_p_=2.86_-0.15_^+0.16^ R_{Earth}_), and EPIC 212690867.01 (2.20_-0.18_^+0.19^ R_{Earth}_) orbit within optimistic habitable zone boundaries set by the "recent Venus" inner limit and the "early Mars" outer limit. In total, our planet sample includes eight moderately irradiated 1.5-3 R_{Earth}_ planet candidates (F_p_~<20 F_{Earth}_) orbiting brighter stars (Ks<11) that are well-suited for atmospheric investigations with the Hubble, Spitzer, and/or James Webb Space Telescopes. Five validated planets orbit relatively bright stars (Kp<12.5) and are expected to yield radial velocity semi-amplitudes of at least 2 m/s. Accordingly, they are possible targets for radial velocity mass measurement with current facilities or the upcoming generation of red optical and near-infrared high-precision RV spectrographs.
- ID:
- ivo://CDS.VizieR/J/ApJ/579/93
- Title:
- KPNO/Deeprange distant cluster survey
- Short Name:
- J/ApJ/579/93
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have conducted an automated search for galaxy clusters within a contiguous 16deg^2^ I-band survey in the north Galactic hemisphere. A matched filter detection algorithm identifies 444 cluster candidates in the range 0.2<~z<~1.2. The full catalog is presented along with the results from a follow-up spectroscopic survey.