- ID:
- ivo://CDS.VizieR/J/AJ/162/117
- Title:
- Radial velocity for 19 RR Lyrae
- Short Name:
- J/AJ/162/117
- Date:
- 21 Mar 2022 00:54:18
- Publisher:
- CDS
- Description:
- We report 272 radial velocities for 19 RR-Lyrae variables. For most of the stars we have radial velocities for the complete pulsation cycle. These data are used to determine robust center-of-mass radial velocities that have been compared to values from the literature in a search for evidence of binary systems. Center-of-mass velocities were determined for each star using Fourier Series and template fits to the radial velocities. Our center-of-mass velocities have uncertainties from {+/-}0.16km/s to {+/-}2.5km/s, with a mean uncertainty of {+/-}0.92km/s. We combined our center-of-mass velocities with values from the literature to look for deviations from the mean center-of-mass velocity of each star. Fifteen RR-Lyrae show no evidence of binary motion (BK And, CI And, Z CVn, DM Cyg, BK Dra, RR Gem, XX Hya, SZ Leo, BX Leo, TT Lyn, CN Lyr, TU Per, U Tri, RV UMa, and AV Vir). In most cases this conclusion is reached due to the sporadic sampling of the center-of-mass velocities over time. Three RR Lyrae show suspicious variation in the center-of-mass velocities that may indicate binary motion but do not prove it (SS Leo, ST Leo, and AO Peg). TU UMa was observed by us near a predicted periastron passage (at 0.14 in orbital phase) but the absence of additional center-of-mass velocities near periastron makes the binary detection, based on radial velocities alone, uncertain. Two stars in our sample show H{gamma} emission in phases 0.9-1.0: SS Leo and TU UMa.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/374/227
- Title:
- Radial velocity in multiple systems
- Short Name:
- J/A+A/374/227
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New close sub-systems are reported and studied in eight visual multiple systems. Elements of one double-lined and eight single-lined spectroscopic orbits are given. Magnitudes, colors, spectral types, masses of individual components are estimated by combining all available data. The visual secondary component of the young binary HD 27638 is a double-lined pair of G-type dwarfs on a 17-day orbit with an unseen but massive (>1.2M_{sun}_) spectroscopic tertiary on an 8-year orbit. The invisible secondary of HD 28271A is also massive, but it is not seen probably owing to a high luminosity of the primary - an F7 star with fast axial rotation and active chromosphere which evolves off the Main Sequence. Two additional companions are found in the visual triple system HD 179484.
- ID:
- ivo://CDS.VizieR/J/A+A/625/A71
- Title:
- Radial velocity measurements for 7 stars
- Short Name:
- J/A+A/625/A71
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Since 1998, a planet-search around main sequence stars within 50pc in the southern hemisphere has been underway with the CORALIE spectrograph at La Silla Observatory. With an observing time span of more than 20 years, the CORALIE survey is able to detect long-term trends in data with masses and separations large enough to select ideal targets for direct imaging. Detecting these giant companion candidates will allow us to start bridging the gap between radial-velocity-detected exoplanets and directly imaged planets and brown dwarfs. Long-term precise Doppler measurements with the CORALIE spectrograph reveal radial-velocity signatures of massive planetary companions and brown dwarfs on long-period orbits. In this paper we report the discovery of new companions orbiting HD 181234, HD 13724, HD 25015, HD 92987 and HD 50499. We also report updated orbital parameters for HD 50499b, HD 92788b and HD 98649b. In addition, we confirm the recent detection of HD 92788c. The newly reported companions span a period range of 15.6 to 40.4 years and a mass domain of 2.93 to 26.77 MJup, the latter of which straddles the nominal boundary between planets and brown dwarfs. We report the detection of five new companions and updated parameters of four known extrasolar planets. We identify at least some of these companions to be promising candidates for imaging and further characterisation.
- ID:
- ivo://CDS.VizieR/J/A+A/576/A48
- Title:
- Radial velocity monitoring for 6 stars
- Short Name:
- J/A+A/576/A48
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe radial-velocity time series obtained by HARPS on the 3.60m telescope in La Silla (ESO, Chile) over ten years and report the discovery of five new giant exoplanets in distant orbits; these new planets orbit the stars HD 564, HD 30669, HD 108341, and BD-11 4672. Their periods range from 492 to 1684-days, semi-major axes range from 1.2 to 2.69AU, and eccentricities range from 0 to 0.85. Their minimum mass ranges from 0.33 to 3.5M_Jup_. We also refine the parameters of two planets announced previously around HD 113538, based on a longer series of measurements. The planets have a period of 663+/-8 and 1818+/-25-days, orbital eccentricities of 0.14+/-0.08 and 0.20+/-0.04, and minimum masses of 0.36+/-0.04 and 0.93+/-0.06M_Jup_. Finally, we report the discovery of a new hot-Jupiter planet around an active star, HD 103720; the planet has a period of 4.5557+/-0.0001-days and a minimum mass of 0.62+/-0.025M_Jup_. We discuss the fundamental parameters of these systems and limitations due to stellar activity in quiet stars with typical 2m/s radial velocity precision.
- ID:
- ivo://CDS.VizieR/J/ApJ/818/34
- Title:
- Radial velocity monitoring of 5 FGK stars
- Short Name:
- J/ApJ/818/34
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the detection of two new long-period giant planets orbiting the stars HD 95872 and HD 162004 ({psi}^1^ Dra B) by the McDonald Observatory planet search. The planet HD 95872b has a minimum mass of 4.6M_Jup_ and an orbital semimajor axis of 5.2AU. The giant planet {psi}^1^ Dra Bb has a minimum mass of 1.5M_Jup_ and an orbital semimajor axis of 4.4AU. Both of these planets qualify as Jupiter analogs. These results are based on over one and a half decades of precise radial velocity (RV) measurements collected by our program using the McDonald Observatory Tull Coude spectrograph at the 2.7m Harlan J. Smith Telescope. In the case of {psi}^1^ Dra B we also detect a long-term nonlinear trend in our data that indicates the presence of an additional giant planet, similar to the Jupiter-Saturn pair. The primary of the binary star system, {psi}^1^ Dra A, exhibits a very large amplitude RV variation due to another stellar companion. We detect this additional member using speckle imaging. We also report two cases --HD 10086 and HD 102870 ({beta} Virginis)-- of significant RV variation consistent with the presence of a planet, but that are probably caused by stellar activity, rather than reflexive Keplerian motion. These two cases stress the importance of monitoring the magnetic activity level of a target star, as long-term activity cycles can mimic the presence of a Jupiter-analog planet.
- ID:
- ivo://CDS.VizieR/J/AJ/149/8
- Title:
- Radial velocity of southern visual multiple stars
- Short Name:
- J/AJ/149/8
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- High-resolution spectra of visual multiple stars were taken in 2008-2009 to detect or confirm spectroscopic subsystems and to determine their orbits. Radial velocities of 93 late-type stars belonging to visual multiple systems were measured by numerical cross-correlation. We provide the individual velocities, the width, and the amplitude of the Gaussians that approximate the correlations. The new information on the multiple systems resulting from these data is discussed. We discovered double-lined binaries in HD 41742B, HD 56593C, and HD 122613AB, confirmed several other known subsystems, and constrained the existence of subsystems in some visual binaries where both components turned out to have similar velocities. The orbits of double-lined subsystems with periods of 148 and 13 days are computed for HD 104471 Aa,Ab and HD 210349 Aa,Ab, respectively. We estimate individual magnitudes and masses of the components in these triple systems and update the outer orbit of HD 104471 AB.
- ID:
- ivo://CDS.VizieR/J/A+A/618/A5
- Title:
- Radial velocity survey of low-mass binaries
- Short Name:
- J/A+A/618/A5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The identification and characterisation of low-mass binaries is of importance for a range of astrophysical investigations. Low-mass binaries in young (~10-100Myr) moving groups (YMGs) in the solar neighborhood are of particular significance as they provide unique opportunities to calibrate stellar models and evaluate the ages and coevality of the groups themselves. Low-mass M-dwarfs have pre-main sequence life times on the order of ~100Myr and therefore are continually evolving along a mass-luminosity track throughout the YMG phase, providing ideal laboratories for precise isochronal dating, if a model-independent dynamical mass can be measured. AstraLux lucky imaging multiplicity surveys have recently identified hundreds of new YMG low-mass binaries, where a subsample of M-dwarf multiples have estimated orbital periods less than 50 years. We have conducted a radial velocity survey of a sample of 29 such targets to complement the astrometric data. This will allow enhanced orbital determinations and precise dynamical masses to be derived in a shorter timeframe than possible with astrometric monitoring alone, and allow for a more reliable isochronal analysis. Here we present radial velocity measurements derived for our sample over several epochs. We report the detection of the three-component spectroscopic multiple 2MASS J05301858-5358483, for which the C component is a new discovery, and forms a tight pair with the B component. Originally identified as a YMG member, we find that this system is a likely old field interloper, whose high chromospheric activity level is caused by tidal spin-up of the tight BC pair. Two other triple systems with a tight pair exist in the sample, 2MASS J04244260-0647313 (previously known) and 2MASS J20163382-0711456, but for the rest of the targets we find that additional tidally synchronized companions are highly unlikely, providing further evidence that their high chromospheric activity levels are generally signatures of youth.
- ID:
- ivo://CDS.VizieR/J/ApJ/694/1085
- Title:
- Radii of exoplanet host stars
- Short Name:
- J/ApJ/694/1085
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present interferometric angular sizes for 12 stars with known planetary companions, for comparison with 28 additional main-sequence stars not known to host planets. For all objects we estimate bolometric fluxes and reddenings through spectral-energy distribution (SED) fits, and in conjunction with the angular sizes, measurements of effective temperature. The angular sizes of these stars are sufficiently small that the fundamental resolution limits of our primary instrument, the Palomar Testbed Interferometer, are investigated at the sub-milliarcsecond level and empirically established based upon known performance limits. We demonstrate that the effective temperature scale as a function of dereddened (V-K)0 color is statistically identical for stars with and without planets. Additionally, in an Appendix we provide SED fits for the 166 stars with known planets which have sufficient photometry available in the literature for such fits; this derived "XO-Rad" database includes homogeneous estimates of bolometric flux, reddening, and angular size.
- ID:
- ivo://CDS.VizieR/J/ApJ/799/180
- Title:
- Radii of 430 KOI Earth- to Neptune-sized planets
- Short Name:
- J/ApJ/799/180
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the cumulative catalog of planets detected by the NASA Kepler mission, we reconstruct the intrinsic occurrence of Earth- to Neptune-size (1-4R_{Earth}_) planets and their distributions with radius and orbital period. We analyze 76711 solar-type (0.8<R_*_/R_{sun}_<1.2) stars with 430 planets on 20-200 day orbits, excluding close-in planets that may have been affected by the proximity to the host star. Our analysis considers errors in planet radii and includes an "iterative simulation" technique that does not bin the data. We find a radius distribution that peaks at 2-2.8 Earth radii, with lower numbers of smaller and larger planets. These planets are uniformly distributed with logarithmic period, and the mean number of such planets per star is 0.46+/-0.03. The occurrence is ~0.66 if planets interior to 20 days are included. We estimate the occurrence of Earth-size planets in the "habitable zone" (defined as 1-2 R_{Earth}_, 0.99-1.7AU for solar-twin stars) as 6.4_-1.1_^+3.4^%. Our results largely agree with those of Petigura et al. (2013PNAS..11019273P), although we find a higher occurrence of 2.8-4 Earth-radii planets. The reasons for this excess are the inclusion of errors in planet radius, updated Huber et al. (2014, J/ApJS/211/2) stellar parameters, and also the exclusion of planets that may have been affected by proximity to the host star.
- ID:
- ivo://CDS.VizieR/J/ApJ/791/10
- Title:
- Radius distribution of planets around cool stars
- Short Name:
- J/ApJ/791/10
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We calculate an empirical, non-parametric estimate of the shape of the period-marginalized radius distribution of planets with periods less than 150 days using the small yet well-characterized sample of cool (T_eff_< 4000 K) dwarf stars in the Kepler catalog. In particular, we present and validate a new procedure, based on weighted kernel density estimation, to reconstruct the shape of the planet radius function down to radii smaller than the completeness limit of the survey at the longest periods. Under the assumption that the period distribution of planets does not change dramatically with planet radius, we show that the occurrence of planets around these stars continues to increase to below 1 R_{sun}_, and that there is no strong evidence for a turnover in the planet radius function. In fact, we demonstrate using many iterations of simulated data that a spurious turnover may be inferred from data even when the true distribution continues to rise toward smaller radii. Finally, the sharp rise in the radius distribution below ~3 R_{sun}_ implies that a large number of planets await discovery around cool dwarfs as the sensitivities of ground-based transit surveys increase.