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- ID:
- ivo://CDS.VizieR/J/AJ/157/100
- Title:
- Radial velocities and bisector spans for K2-287
- Short Name:
- J/AJ/157/100
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of K2-287b, a Saturn mass planet orbiting a G-dwarf with a period of P~15 days. First uncovered as a candidate using K2 campaign 15 data, follow-up photometry and spectroscopy were used to determine a mass M_P_=0.317+/-0.026 M_J_, radius R_P_=0.833+/-0.013 R_J_, period P=14.893291+/-0.000025 days, and eccentricity e=0.476+/-0.026. The host star is a metal-rich V=11.410+/-0.129 mag G-dwarf for which we estimate a mass M_*_=1.056_-0.021_^+0.022^ M_{sun}__, radius R_*_=1.070+/-0.010 R_{sun}_, metallicity [Fe/H]=0.20+/-0.05, and T_eff_=5673+/-75 K. This warm eccentric planet with a time-averaged equilibrium temperature of T_eq_~800 K adds to the small sample of giant planets orbiting nearby stars whose structure is not expected to be affected by stellar irradiation. Follow-up studies on the K2-287 system could help constrain theories of planet migration in close-in orbits.
- ID:
- ivo://CDS.VizieR/J/ApJ/835/251
- Title:
- Radial velocities and BVIc LCs of the EB* CU Cnc
- Short Name:
- J/ApJ/835/251
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Spectral features, radial velocities, elemental abundance estimates, other spectral data, and BVI_C_ light curves are reported for the double-M dwarf eclipsing binary CU Cancri-a good target for a radius check versus the Zero Age Main Sequence (ZAMS) due to the low component masses and corresponding very slow evolutionary expansion. The estimate of [Fe/H] is about 0.4, although continuum placement and other difficulties due to line crowding introduce the usual uncertainties for red dwarfs. Detection of the LiI{lambda}6707 line was attempted, with an estimated upper limit of 50m{AA}. Spectral and photometric indicators of stellar activity are described and illustrated. Other objectives were to measure the stellar radii via simultaneous velocity and light-curve solutions of earlier and new data while also improving the ephemeris by filling gaps in timewise coverage with the new velocities and eclipse data from the new light curves. The radii from our solutions agree within about 2% with those from Ribas, being slightly larger than expected for most estimates of the ZAMS. Some aspects of the red dwarf radius anomaly are briefly discussed. Evolution tracks show only very slight age-related expansion for masses near those in CU Cnc. Such expansion could be significant if CU Cnc were similar in age to the Galaxy, but then its Galactic velocity components should be representative of Population II, and they are not.
- ID:
- ivo://CDS.VizieR/J/AJ/130/794
- Title:
- Radial velocities and BV photometry of HD 144110
- Short Name:
- J/AJ/130/794
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New spectroscopic and photometric observations of HD 144110 have been used to obtain an improved orbital element solution and determine some basic properties of the system. This chromospherically active, double-lined spectroscopic binary has an orbital period of 1.6714012days and a circular orbit. We classify the components as G5 V and K0 V and suggest that they are slightly metal-rich. The photometric observations indicate that the rotation of HD 144110 is synchronous with the orbital period. Despite the short orbital period, no evidence of eclipses is seen in our photometry.
- ID:
- ivo://CDS.VizieR/J/ApJ/454/788
- Title:
- Radial velocities and BV photometry of NGC 3201
- Short Name:
- J/ApJ/454/788
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- BV CCD frames have been used to derive surface brightness profiles for NGC 3201 which extend out to ~18'. A total of 857 radial velocities with median precision ~1km/s for 399 member giants have been used to trace the velocity dispersion profile out to 32.1' (the approximate tidal radius determined from fits of single-mass, isotropic King-Michie models to the cluster surface brightness profiles). The median difference in radial velocity for stars on either side of an imaginary axis stepped through the cluster in 1 deg increments shows a statistically significant maximum amplitude of 1.22+/-0.25km/s. We discuss several possible explanations of this result, including (1) cluster rotation, (2) preferential stripping of stars on prograde orbits near the limiting radius, (3) the projection of the cluster space velocity onto the plane of the sky, and (4) a slight drift in the velocity zero point. It is difficult to unambiguously identify the primary cause of the observed structure in the velocity field, however, and we suspect that all of the above processes may play a role. The BV surface brightness profiles and radial velocities have been modeled with both single- and multimass King-Michie models and nonparametric techniques. The corresponding density profiles and M/L profiles show good agreement over the interval 1.5<~R<~10pc, and both approaches suggest a steady rise in M/L with distance from the cluster center. Due to the low cluster luminosity we are unable to place useful constraints on the anisotropy of M/L_B~M/L_V~2.0+/-0.2 for the multimass and nonparametric models, compared to ~1.65+/-0.15 for models having equal-mass stars. Our best-fit, multimass models have mass function slopes of x~0.75+/-0.25, consistent with recent findings that the form of the mass function depends on the position relative to the potential of the Galaxy.
- ID:
- ivo://CDS.VizieR/J/ApJ/674/857
- Title:
- Radial velocities and CT1 magnitudes in M60 galaxy
- Short Name:
- J/ApJ/674/857
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present radial velocity measurements for globular clusters in M60, a giant elliptical galaxy in the Virgo Cluster. Target globular cluster candidates were selected using Washington photometry based on deep 16'x16' images taken at the KPNO 4m telescope and using VI photometry derived from Hubble Space Telescope WFPC2 archival images. The spectra of the target objects were obtained with the Multi-Object Spectrograph at the Canada-France-Hawaii Telescope. We have measured the radial velocities of 111 objects in the field of M60: 93 globular clusters (72 blue globular clusters with 1.0<=C-T1<1.7, and 21 red globular clusters with 1.7<=C-T1<2.4), 11 foreground stars, six small galaxies, and the nucleus of M60.
- ID:
- ivo://CDS.VizieR/J/ApJ/743/167
- Title:
- Radial velocities and membership in Pal 13
- Short Name:
- J/ApJ/743/167
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Keck/DEIMOS spectroscopy and Canada-France-Hawaii Telescope/MegaCam photometry for the Milky Way globular cluster Palomar 13. We triple the number of spectroscopically confirmed members, including many repeat velocity measurements. Palomar 13 is the only known globular cluster with possible evidence for dark matter, based on a Keck/High Resolution Echelle Spectrometer 21 star velocity dispersion of {sigma}=2.2+/-0.4km/s. We reproduce this measurement, but demonstrate that it is inflated by unresolved binary stars. For our sample of 61 stars, the velocity dispersion is {sigma}=0.7^+0.6^_-0.5_km/s. Combining our DEIMOS data with literature values, our final velocity dispersion is {sigma}=0.4^+0.4^_-0.3_km/s. We determine a spectroscopic metallicity of [Fe/H]=-1.6+/-0.1 dex, placing a 1{sigma} upper limit of {sigma}_[Fe/H]_~0.2dex on any internal metallicity spread. We determine Palomar 13's total luminosity to be M_V_=-2.8+/-0.4, making it among the least luminous known globular clusters.
- ID:
- ivo://CDS.VizieR/J/ApJ/634/625
- Title:
- Radial velocities and photometry of GJ 876
- Short Name:
- J/ApJ/634/625
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- High-precision, high-cadence radial velocity monitoring over the past 8yr at the W. M. Keck Observatory reveals evidence for a third planet orbiting the nearby (4.69pc) dM4 star GJ 876. The residuals of three-body Newtonian fits, which include GJ 876 and Jupiter-mass companions b and c, show significant power at a periodicity of 1.9379days. Self-consistently fitting the radial velocity data with a model that includes an additional body with this period significantly improves the quality of the fit.
- ID:
- ivo://CDS.VizieR/J/ApJ/768/155
- Title:
- Radial velocities and photometry of HD 38529 system
- Short Name:
- J/ApJ/768/155
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The transit signature of exoplanets provides an avenue through which characterization of exoplanetary properties may be undertaken, such as studies of mean density, structure, and atmospheric composition. The Transit Ephemeris Refinement and Monitoring Survey is a program to expand the catalog of transiting planets around bright host stars by refining the orbits of known planets discovered with the radial velocity technique. Here we present results for the HD 38529 system. We determine fundamental properties of the host star through direct interferometric measurements of the radius and through spectroscopic analysis. We provide new radial velocity measurements that are used to improve the Keplerian solution for the two known planets, and we find no evidence for a previously postulated third planet. We also present 12 years of precision robotic photometry of HD 38529 that demonstrate the inner planet does not transit and the host star exhibits cyclic variations in seasonal mean brightness with a timescale of approximately six years.
- ID:
- ivo://CDS.VizieR/J/AJ/154/188
- Title:
- Radial velocities and photometry of K2-114&K2-115
- Short Name:
- J/AJ/154/188
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the first results from a search for transiting warm Jupiter exoplanets-gas giant planets receiving stellar irradiation below about 10^8^ erg/s/cm^2^, equivalent to orbital periods beyond about 10 days around Sun-like stars. We have discovered two transiting warm Jupiter exoplanets initially identified as transiting candidates in K2 photometry. K2-114b has a mass of 1.85_-0.22_^+0.23^ M_J_, a radius of 0.942_-0.020_^+0.032^ R_J_, and an orbital period of 11.4 days. K2-115b has a mass of 0.84_-0.20_^+0.18^ M_J_, a radius of 1.115_-0.061_^+0.057^ R_J_, and an orbital period of 20.3 days. Both planets are among the longest-period transiting gas giant planets with a measured mass, and they are orbiting relatively old host stars. Both planets are not inflated, as their radii are consistent with theoretical expectations. Their position in the planet radius-stellar irradiation diagram is consistent with the scenario where the radius-irradiation correlation levels off below about 10^8^ erg/s/cm^2^, suggesting that for warm Jupiters stellar irradiation does not play a significant role in determining the planet radius. We also report our identification of another K2 transiting warm Jupiter candidate, EPIC 212504617, as a false positive.
