- ID:
- ivo://CDS.VizieR/J/A+A/513/L7
- Title:
- Post common envelope binaries from SDSS. VIII
- Short Name:
- J/A+A/513/L7
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a large survey of post common envelope binaries (PCEBs) among white dwarf/main sequence (WDMS) binaries from the SDSS that allows to determine the fraction of PCEBs as a function of secondary star mass and therewith to ultimately test the disrupted magnetic braking hypothesis. We obtained multiple spectroscopic observations spread over at least two nights of 589 WDMS binaries. Using mostly the NaI 8183.27,8194.81 absorption doublet we determined the corresponding radial velocities.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/796/48
- Title:
- Potential exoplanet targets with Palomar/TripleSpec
- Short Name:
- J/ApJ/796/48
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Here we explore the capabilities of NASA's 3.0 m Infrared Telescope Facility (IRTF) and SpeX spectrometer and the 5.08 m Hale telescope with the TripleSpec spectrometer with near-infrared H-, K-, and L-band measurements of HD 209458b's secondary eclipse. Our IRTF/SpeX data are the first absolute L-band spectroscopic emission measurements of any exoplanet other than the hot Jupiter HD 189733b. Previous measurements of HD 189733b's L band indicate bright emission hypothesized to result from non-LTE CH_4_{nu}_3_ fluorescence. We do not detect a similar bright 3.3 {mu}m feature to ~3{sigma}, suggesting that fluorescence does not need to be invoked to explain HD 209458b's L-band measurements. The validity of our observation and reduction techniques, which decrease the flux variance by up to 2.8 orders of magnitude, is reinforced by 1{sigma} agreement with existent Hubble/NICMOS and Spitzer/IRAC1 observations that overlap the H, K, and L bands, suggesting that both IRTF/SpeX and Palomar/TripleSpec can measure an exoplanet's emission with high precision.
- ID:
- ivo://CDS.VizieR/J/ApJ/807/45
- Title:
- Potentially habitable planets orbiting M dwarfs
- Short Name:
- J/ApJ/807/45
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an improved estimate of the occurrence rate of small planets orbiting small stars by searching the full four-year Kepler data set for transiting planets using our own planet detection pipeline and conducting transit injection and recovery simulations to empirically measure the search completeness of our pipeline. We identified 156 planet candidates, including one object that was not previously identified as a Kepler Object of Interest. We inspected all publicly available follow-up images, observing notes, and centroid analyses, and corrected for the likelihood of false positives. We evaluated the sensitivity of our detection pipeline on a star-by-star basis by injecting 2000 transit signals into the light curve of each target star. For periods shorter than 50 days, we find 0.56^+0.06^_-0.05_ Earth-size planets (1-1.5R_{Earth}_) and 0.46^+0.07^_-0.05_ super-Earths (1.5-2R_{Earth}_) per M dwarf. In total, we estimate a cumulative planet occurrence rate of 2.5+/-0.2 planets per M dwarf with radii 1-4R_{Earth}_ and periods shorter than 200 days. Within a conservatively defined habitable zone (HZ) based on the moist greenhouse inner limit and maximum greenhouse outer limit, we estimate an occurrence rate of 0.16^+0.17^_-0.07_ Earth-size planets and 0.12^+0.10^_-0.05_ super-Earths per M dwarf HZ. Adopting the broader insolation boundaries of the recent Venus and early Mars limits yields a higher estimate of 0.24^+0.18^_-0.08_ Earth-size planets and 0.21^+0.11^_-0.06_ super-Earths per M dwarf HZ. This suggests that the nearest potentially habitable non-transiting and transiting Earth-size planets are 2.6+/-0.4pc and 10.6^+1.6^_-1.8_pc away, respectively. If we include super-Earths, these distances diminish to 2.1+/-0.2pc and 8.6^+0.7^_-0.8_pc.
- ID:
- ivo://CDS.VizieR/J/ApJS/217/18
- Title:
- Potential transit signals in Kepler Q1-Q17
- Short Name:
- J/ApJS/217/18
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a search for potential transit signals in the full 17-quarter data set collected during Kepler's primary mission that ended on 2013 May 11, due to the on board failure of a second reaction wheel needed to maintain high precision, fixed, pointing. The search includes a total of 198646 targets, of which 112001 were observed in every quarter and 86645 were observed in a subset of the 17 quarters. For the first time, this multi-quarter search is performed on data that have been fully and uniformly reprocessed through the newly released version of the Data Processing Pipeline. We find a total of 12669 targets that contain at least one signal that meets our detection criteria: periodicity of the signal, a minimum of three transit events, an acceptable signal-to-noise ratio, and four consistency tests that suppress many false positives. Each target containing at least one transit-like pulse sequence is searched repeatedly for other signals that meet the detection criteria, indicating a multiple planet system. This multiple planet search adds an additional 7698 transit-like signatures for a total of 20367. Comparison of this set of detected signals with a set of known and vetted transiting planet signatures in the Kepler field of view shows that the recovery rate of the search is 90.3%. We review ensemble properties of the detected signals and present various metrics useful in validating these potential planetary signals. We highlight previously undetected transit-like signatures, including several that may represent small objects in the habitable zone of their host stars.
- ID:
- ivo://CDS.VizieR/J/ApJ/842/83
- Title:
- Praesepe members rotational periods from K2 LCs
- Short Name:
- J/ApJ/842/83
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyze K2 light curves for 794 low-mass (1>~M_*_>~0.1M_{sun}_) members of the ~650Myr old open cluster Praesepe and measure rotation periods (P_rot_) for 677 of these stars. We find that half of the rapidly rotating >~0.3M_{sun}_ stars are confirmed or candidate binary systems. The remaining >~0.3M_{sun}_ fast rotators have not been searched for companions, and are therefore not confirmed single stars. We previously found that nearly all rapidly rotating 0.3M_{sun}_ stars in the Hyades are binaries, but we require deeper binary searches in Praesepe to confirm whether binaries in these two co-eval clusters have different P_rot_ distributions. We also compare the observed P_rot_ distribution in Praesepe to that predicted by models of angular-momentum evolution. We do not observe the clear bimodal P_rot_ distribution predicted by Brown (2014ApJ...789..101B) for >0.5M_{sun}_ stars at the age of Praesepe, but 0.25-0.5M_{sun}_ stars do show stronger bimodality. In addition, we find that >60% of early M dwarfs in Praesepe rotate more slowly than predicted at 650Myr by Matt+ (2015ApJ...799L..23M), which suggests an increase in braking efficiency for these stars relative to solar-type stars and fully convective stars. The incompleteness of surveys for binaries in open clusters likely impacts our comparison with these models since the models only attempt to describe the evolution of isolated single stars.
- ID:
- ivo://CDS.VizieR/J/ApJ/715/1050
- Title:
- Predicted abundances for extrasolar planets. I.
- Short Name:
- J/ApJ/715/1050
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Extrasolar planet host stars have been found to be enriched in key planet-building elements. These enrichments have the potential to drastically alter the composition of material available for terrestrial planet formation. Here, we report on the combination of dynamical models of late-stage terrestrial planet formation within known extrasolar planetary systems with chemical equilibrium models of the composition of solid material within the disk. This allows us to determine the bulk elemental composition of simulated extrasolar terrestrial planets. A wide variety of resulting planetary compositions are found, ranging from those that are essentially "Earth like", containing metallic Fe and Mg silicates, to those that are dominated by graphite and SiC. This shows that a diverse range of terrestrial planets may exist within extrasolar planetary systems.
- ID:
- ivo://CDS.VizieR/J/MNRAS/475/3090
- Title:
- Predicted properties for 468 RV planets
- Short Name:
- J/MNRAS/475/3090
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The CHaracterizing ExOPlanets Satellite (CHEOPS) mission is planned for launch next year with a major objective being to search for transits of known radial velocity (RV) planets, particularly those orbiting bright stars. Since the RV method is only sensitive to planetary mass, the radii, transit depths and transit signal-to-noise values of each RV planet are, a priori, unknown. Using an empirically calibrated probabilistic mass-radius relation, forecaster, we address this by predicting a catalogue of homogeneous credible intervals for these three keys terms for 468 planets discovered via RVs. Of these, we find that the vast majority should be detectable with CHEOPS, including terrestrial bodies, if they have the correct geometric alignment. In particular, we predict that 22 mini-Neptunes and 82 Neptune-sized planets would be suitable for detection and that more than 80 per cent of these will have apparent magnitude of V<10, making them highly suitable for follow-up characterization work. Our work aims to assist the CHEOPS team in scheduling efforts and highlights the great value of quantifiable, statistically robust estimates for upcoming exoplanetary missions.
- ID:
- ivo://CDS.VizieR/J/ApJ/880/49
- Title:
- Predictions of giant exoplanet host star's
- Short Name:
- J/ApJ/880/49
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The presence of certain elements within a star, and by extension its planet, strongly impacts the formation and evolution of the planetary system. The positive correlation between a host star's iron content and the presence of an orbiting giant exoplanet has been confirmed; however, the importance of other elements in predicting giant planet occurrence is less certain despite their central role in shaping internal planetary structure. We designed and applied a machine-learning algorithm to the Hypatia Catalog to analyze the stellar abundance patterns of known host stars to determine those elements important in identifying potential giant exoplanet host stars. We analyzed a variety of different elements ensembles-namely, volatiles, lithophiles, siderophiles, and Fe. We show that the relative abundances of oxygen, carbon, and sodium, in addition to iron, are influential indicators of the presence of a giant planet. We demonstrate the predictive power of our algorithm by analyzing stars with known giant planets and found that they had median 75% prediction score. We present a list of ~350 stars with no currently discovered planets that have a >=90% prediction probability likelihood of hosting a giant exoplanet. We investigated archival HARPS data and found significant trends that HIP 62345, HIP 71803, and HIP 10278 host long-period giant planet companions with estimated minimum M_p_sin(i) values of 3.7, 6.8, and 8.5M_J_, respectively. We anticipate that our findings will revolutionize future target selection, the role that elements play in giant planet formation, and the determination of giant planet interior structure models.
- ID:
- ivo://CDS.VizieR/J/ApJ/696/L84
- Title:
- Primordial circumstellar disks in binary systems
- Short Name:
- J/ApJ/696/L84
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We combine the results from several multiplicity surveys of pre-main-sequence stars located in four nearby star-forming regions with Spitzer data from three different Legacy Projects. This allows us to construct a sample of 349 targets, including 125 binaries, which we use to to investigate the effect of companions on the evolution of circumstellar disks. We find that the distribution of projected separations of systems with Spitzer excesses is significantly different (P~2.4e-5, according to the K-S test for binaries with separations less than 400AU) from that of systems lacking evidence for a disk. As expected, systems with projected separations less than 40AU are half as likely to retain at least one disk than are systems with projected separations in the 40-400AU range. These results represent the first statistically significant evidence for a correlation between binary separation and the presence of an inner disk (r~1AU). Several factors (e.g., the incompleteness of the census of close binaries, the use of unresolved disk indicators, and projection effects) have previously masked this correlation in smaller samples. We discuss the implications of our findings for circumstellar disk lifetimes and the formation of planets in multiple systems.
- ID:
- ivo://CDS.VizieR/J/ApJ/807/170
- Title:
- Prograde vs retrogade motions. II. KOIs
- Short Name:
- J/ApJ/807/170
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Mazeh et al. (Paper I: 2015ApJ...800..142M) have presented an approach that can, in principle, use the derived transit timing variation (TTV) of some transiting planets observed by the Kepler mission to distinguish between the prograde and retrograde motion of their orbits with respect to their parent stars' rotation. The approach utilizes TTVs induced by spot-crossing events that occur when the planet moves across a spot on the stellar surface, looking for a correlation between the derived TTVs and the stellar brightness derivatives at the corresponding transits. This can work even in data that cannot temporally resolve the spot-crossing events themselves. Here, we apply this approach to the Kepler KOIs, identifying nine systems where the photometric spot modulation is large enough and the transit timing accurate enough to allow detection of a TTV-brightness-derivatives correlation. Of those systems, five show highly significant prograde motion (Kepler-17b, Kepler-71b, KOI-883.01, KOI-895.01, and KOI-1074.01), while no system displays retrograde motion, consistent with the suggestion that planets orbiting cool stars have prograde motion. All five systems have impact parameter 0.2<~b<~0.5, and all systems within that impact parameter range show significant correlation, except HAT-P-11b where the lack of a correlation follows its large stellar obliquity. Our search suffers from an observational bias against detection of high impact parameter cases, and the detected sample is extremely small. Nevertheless, our findings may suggest that stellar spots, or at least the larger ones, tend to be located at low stellar latitude, but not along the stellar equator, similar to the Sun.