- ID:
- ivo://CDS.VizieR/J/AJ/155/136
- Title:
- Planets orbiting bright stars in K2 campaigns 0-10
- Short Name:
- J/AJ/155/136
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Since 2014, NASA's K2 mission has observed large portions of the ecliptic plane in search of transiting planets and has detected hundreds of planet candidates. With observations planned until at least early 2018, K2 will continue to identify more planet candidates. We present here 275 planet candidates observed during Campaigns 0-10 of the K2 mission that are orbiting stars brighter than 13 mag (in Kepler band) and for which we have obtained high-resolution spectra (R=44000). These candidates are analyzed using the vespa package in order to calculate their false-positive probabilities (FPP). We find that 149 candidates are validated with an FPP lower than 0.1%, 39 of which were previously only candidates and 56 of which were previously undetected. The processes of data reduction, candidate identification, and statistical validation are described, and the demographics of the candidates and newly validated planets are explored. We show tentative evidence of a gap in the planet radius distribution of our candidate sample. Comparing our sample to the Kepler candidate sample investigated by Fulton et al. (2017, J/AJ/154/109), we conclude that more planets are required to quantitatively confirm the gap with K2 candidates or validated planets. This work, in addition to increasing the population of validated K2 planets by nearly 50% and providing new targets for follow-up observations, will also serve as a framework for validating candidates from upcoming K2 campaigns and the Transiting Exoplanet Survey Satellite, expected to launch in 2018.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/552/A119
- Title:
- Planet-star and moon-planet interaction
- Short Name:
- J/A+A/552/A119
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Electromagnetic coupling of planetary moons with their host planets is well observed in our solar system. Similar couplings of extrasolar planets with their central stars have been studied observationally on an individual as well as on a statistical basis. We aim to model and to better understand the energetics of planet star and moon planet interactions on an individual and as well as on a statistical basis.
- ID:
- ivo://CDS.VizieR/J/AZh/79/738
- Title:
- Population model of binary stars in the Galaxy
- Short Name:
- J/AZh/79/738
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A comparative study of the population of the galactic binary stars is performed for two modes of star formation: star formation at a constant rate over 10^+10^yrs, and a burst of star formation that reprocesses the same mass of gas into stars over 10^+9^yrs. Estimates are presented for the star formation rates and populations of about 100 types of binaries and the products of their evolution.
- ID:
- ivo://CDS.VizieR/J/MNRAS/441/3543
- Title:
- Possible planets around A stars
- Short Name:
- J/MNRAS/441/3543
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Kepler photometry of A stars shows that a considerable fraction (about 19 per cent) have a peculiar feature in the periodogram. This feature consists of a broad peak, thought to be due to differential rotation in a spotted star, and a sharp peak at slightly higher frequency. The pattern clearly involves some widespread stellar property and the sharp peak implies a strictly coherent periodicity. We investigate the possibility that the periodicity is due to rotation, pulsation or an orbital effect. We argue that neither rotation nor pulsation can provide a suitable, testable, explanation. We suggest that the sharp feature could be due to a planet in synchronous orbit around the rapidly rotating, spotted A star, not necessarily in transit. Spectroscopic observations of sufficient precision are required to falsify this hypothesis.
- 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.
- 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/759/19
- Title:
- Precise radial velocities of {rho}^1^ Cancri
- Short Name:
- J/ApJ/759/19
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a mass determination for the transiting super-Earth {rho}^1^ Cancri e based on nearly 700 precise radial velocity (RV) measurements. This extensive RV data set consists of data collected by the McDonald Observatory planet search and published data from Lick and Keck observatories. We obtained 212 RV measurements with the Tull Coud\'e Spectrograph at the Harlan J. Smith 2.7m Telescope and combined them with a new Doppler reduction of the 131 spectra that we have taken in 2003-2004 with the High-Resolution Spectrograph (HRS) at the Hobby-Eberly Telescope for the original discovery of {rho}^1^ Cancri e. Using this large data set we obtain a five-planet Keplerian orbital solution for the system and measure an RV semi-amplitude of K=6.29+/-0.21m/s for {rho}^1^ Cnc e and determine a mass of 8.37+/-0.38M_{oplus}_. The uncertainty in mass is thus less than 5%. This planet was previously found to transit its parent star, which allowed them to estimate its radius. Combined with the latest radius estimate from Gillon et al. (Cat. J/A+A/539/A28), we obtain a mean density of {rho}=4.50+/-0.20g/cm3. The location of {rho}^1^ Cnc e in the mass-radius diagram suggests that the planet contains a significant amount of volatiles, possibly a water-rich envelope surrounding a rocky core.
