- ID:
- ivo://CDS.VizieR/J/AJ/135/2496
- Title:
- Near-IR survey of Class I protostars
- Short Name:
- J/AJ/135/2496
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the observational results of a near-infrared survey of a large sample of Class I protostars designed to determine the Class I binary separation distribution from ~100AU to ~5000AU. We have selected targets from a new sample of 267 nearby candidate Class I objects. This sample is well understood, consists of mostly Class I young stellar objects (YSOs) within 1kpc, has targets selected from the whole sky, and is not biased by previous studies of star formation.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/466/1868
- Title:
- Neptune-like planets low-density overabundance
- Short Name:
- J/MNRAS/466/1868
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a uniform analysis of the atmospheric escape rate of Neptune-like planets with estimated radius and mass (restricted to M_p_<30M_{Earth}_). For each planet, we compute the restricted Jeans escape parameter, {Lambda}, for a hydrogen atom evaluated at the planetary mass, radius, and equilibrium temperature. Values of {Lambda}<=20 suggest extremely high mass-loss rates. We identify 27 planets (out of 167) that are simultaneously consistent with hydrogen-dominated atmospheres and are expected to exhibit extreme mass-loss rates. We further estimate the mass-loss rates (L_hy_) of these planets with tailored atmospheric hydrodynamic models. We compare L_hy_ to the energy-limited (maximum-possible high-energy driven) mass-loss rates. We confirm that 25 planets (15 per cent of the sample) exhibit extremely high mass-loss rates (L_hy_>0.1M_{Earth}_/Gyr), well in excess of the energy-limited mass-loss rates. This constitutes a contradiction, since the hydrogen envelopes cannot be retained given the high mass-loss rates. We hypothesize that these planets are not truly under such high mass-loss rates. Instead, either hydrodynamic models overestimate the mass-loss rates, transit-timing-variation measurements underestimate the planetary masses, optical transit observations overestimate the planetary radii (due to high-altitude clouds), or Neptunes have consistently higher albedos than Jupiter planets. We conclude that at least one of these established estimations/techniques is consistently producing biased values for Neptune planets. Such an important fraction of exoplanets with misinterpreted parameters can significantly bias our view of populations studies, like the observed mass-radius distribution of exoplanets for example.
- ID:
- ivo://CDS.VizieR/J/AJ/154/195
- Title:
- New binaries in the {epsilon} Cha association
- Short Name:
- J/AJ/154/195
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Adaptive Optics-aided speckle observations of 47 young stars in the {epsilon} Cha association made at the 4 m Southern Astrophysical Research Telescope in the I-band. We resolved 10 new binary pairs, 5 previously known binaries, and 2 triple systems, also previously known. In the separation range between 4 and 300 au, the 30 association members of spectral types G0 and later host 6 binary companions, leading to the raw companion frequency of 0.010+/-0.04 per decade of separation, comparable to the main sequence dwarfs in the field. On the other hand, all five massive association members of spectral types A and B have companions in this range. We discuss the newly resolved and known binaries in our sample. Observed motions in the triple system {epsilon} Cha, composed of three similar B9V stars, can be described by tentative orbits with periods 13 and ~900 years and a large mutual inclination.
- ID:
- ivo://CDS.VizieR/J/other/JDSO/15.434
- Title:
- New Binary Systems from Data of Gaia DR2
- Short Name:
- J/other/JDSO/15.
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- The author describes the discovery of 4 new pairs of stars with almost identical proper motions and parallaxes (from Gaia DR2 data).
- ID:
- ivo://CDS.VizieR/J/AJ/134/741
- Title:
- New close binary systems from the SDSS DR5
- Short Name:
- J/AJ/134/741
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the latest catalog of more than 1200 spectroscopically selected close binary systems observed with the Sloan Digital Sky Survey through Data Release Five. We use the catalog to search for magnetic white dwarfs in cataclysmic variable progenitor systems. Given that approximately 25% of cataclysmic variables contain a magnetic white dwarf, and that our large sample of close binary systems should contain many progenitors of cataclysmic variables, it is quite surprising that we find only two potential magnetic white dwarfs in this sample.
- ID:
- ivo://CDS.VizieR/J/MNRAS/429/859
- Title:
- New companions to nearby low-mass stars
- Short Name:
- J/MNRAS/429/859
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present high-angular-resolution optical I-band imaging of 451 late K to mid-M nearby stars. These observations have been performed with Astralux and FastCam using the lucky imaging technique. We found 70 companions with separations between 0.1 and 3.5-arcsec, out of which 28 are new discoveries. We derive a total binary fraction of 20.3^+6.9^_-5.2_ per cent. Follow-up observations have been carried out for 16 of these new binaries and all of them were confirmed as physically associated systems. Parallaxes are available for 70 per cent of the binary sample, providing reliable estimates of physical separations. We have measured separations and position angles as an initial stage for a systematic follow-up aimed to determine orbital parameters.
- ID:
- ivo://CDS.VizieR/J/PASP/110/1012
- Title:
- New double stars from HST
- Short Name:
- J/PASP/110/1012
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Data from the Hubble Space Telescope (HST) Fine Guidance Sensor (FGS) interferometers, covering 22 months of guide-star acquisition operations, have been analyzed for evidence of stellar duplicity. The data comprise a survey of observed guide stars, all of which are taken from the HST Guide Star Catalog, ranging in magnitude from 9 to 14. The survey results cover a parameter space for the newly found doubles, for the fainter stars, which are of smaller limiting angular separations than in any previous surveys. The normal HST engineering telemetry data from 13,979 acquisitions on 4882 stars have been processed. The FGS guidance data can reveal duplicity with separations ranging from approximately 30mas, for the brighter stars, with small magnitude differences, up to the neighborhood of 500mas, and in some cases to 1000mas. The fraction of guide stars indicating duplicity is a function of the statistical criteria used but is over 5% at a very high level of confidence. It is possible that if some of the brighter and closer pairs could be identified as nearby, then their orbital motions would be rapid enough to allow a mass and distance determination on a timescale of a decade if followed with ground-based interferometric and spectroscopic instruments. A brief catalog of doubles is given, nearly all of which are of certain duplicity. Information for accessing on-line catalogs of large numbers of stars with lesser, but nevertheless strong, probabilities of duplicity and also for the solutions for duplicity from all acquisitions is provided.
- ID:
- ivo://CDS.VizieR/J/A+A/555/A58
- Title:
- New Kepler planetary candidates
- Short Name:
- J/A+A/555/A58
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present first results of our efforts to re-analyze the Kepler photometric dataset, searching for planetary transits using an alternative processing pipeline to the one used by the Kepler mission The SARS pipeline was tried and tested extensively by processing all available CoRoT mission data. For this first paper of the series we used this pipeline to search for (additional) planetary transits only in a small subset of stars - the Kepler objects of interest (KOIs), which are already known to include at least one promising planet candidate.
- ID:
- ivo://CDS.VizieR/J/AJ/153/36
- Title:
- New minima timings and RVs for 3 eclipsing binaries
- Short Name:
- J/AJ/153/36
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Eclipsing binaries remain crucial objects for our understanding of the universe. In particular, those that are components of multiple systems can help us solve the problem of the formation of these systems. Analysis of the radial velocities together with the light curve produced for the first time precise physical parameters of the components of the multiple systems V773 Cas, QS Aql, and BR Ind. Their visual orbits were also analyzed, which resulted in slightly improved orbital elements. What is typical for all these systems is that their most dominant source is the third distant component. The system V773 Cas consists of two similar G1-2V stars revolving in a circular orbit and a more distant component of the A3V type. Additionally, the improved value of parallax was calculated to be 17.6 mas. Analysis of QS Aql resulted in the following: the inner eclipsing pair is composed of B6V and F1V stars, and the third component is of about the B6 spectral type. The outer orbit has high eccentricity of about 0.95, and observations near its upcoming periastron passage between the years 2038 and 2040 are of high importance. Also, the parallax of the system was derived to be about 2.89 mas, moving the star much closer to the Sun than originally assumed. The system BR Ind was found to be a quadruple star consisting of two eclipsing K dwarfs orbiting each other with a period of 1.786 days; the distant component is a single-lined spectroscopic binary with an orbital period of about 6 days. Both pairs are moving around each other on their 148 year orbit.
- ID:
- ivo://CDS.VizieR/J/MNRAS/355/585
- Title:
- New Northern common proper-motion pairs
- Short Name:
- J/MNRAS/355/585
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A list of 705 new Northern Celestial Hemisphere common proper motion pairs between 18 hours and 6 hours Right Ascension and 0 degrees and roughly 45 degrees Declination as derived from the Second U.S. Naval Observatory CCD Astrograph Catalog is presented, along with details of separation, motion, brightness and colour. This list is supplemented by a further 267 such pairs, derived in exactly the same way as the above 705 within the same Declination range, but for the region between 6 hours and 18 hours Right Ascension that was not included in the printed paper.
