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The Young Massive Star Cluster Westerlund 2 Observed with MUSE. II. MUSEpack—A Python Package to Analyze the Kinematics of Young Star Clusters
Grebel, Eva K.; Sabbi, Elena; Nota, Antonella +5 more
We mapped the Galactic young massive star cluster Westerlund 2 with the integral field spectrograph MUSE (spatial resolution: 0.2 arcsec px-1, spectral resolution: Δλ = 1.25 Å, wavelength range: 4600-9350 Å) mounted on the Very Large Telescope. We present the fully reduced data set and introduce our new Python package “MUSEpack,” which …
The Convective Electric Field Influence on the Cold Plasma and Diamagnetic Cavity of Comet 67P
Henri, Pierre; Nilsson, Hans; Edberg, Niklas J. T. +5 more
We studied the distribution of cold electrons (<1 eV) around comet 67P/Churyumov-Gerasimenko with respect to the solar wind convective electric field direction. The cold plasma was measured by the Langmuir Probe instrument and the direction of the convective electric field {\boldsymbol{E}} conv = -{\boldsymbol{v}} × {\boldsymbol{B}} …
Observations of the Ultraviolet-bright Star Barnard 29 in the Globular Cluster M13 (NGC 6205)
Chayer, Pierre; Reid, I. N.; Dixon, William V. +1 more
We have analyzed spectra from FUSE, COS, GHRS, and Keck HIRES of the UV-bright star Barnard 29 in M13 (NGC 6205). By comparing the photospheric abundances derived from multiple ionization states of C, N, O, Si, and S, we infer an effective temperature {T}eff} = 21,400 ± 400 K. Balmer-line fits yield a surface gravity {log}g = 3.10 ± 0.0…
The Possible Astrometric Signature of a Planetary-mass Companion to the Nearby Young Star TW Piscis Austrini (Fomalhaut B): Constraints from Astrometry, Radial Velocities, and Direct Imaging
Esposito, Thomas M.; Kalas, Paul; De Rosa, Robert J. +5 more
We present constraints on the presence of substellar companions to the nearby (d ∼ 7.6 pc) young (440 ± 40 Myr) K4Ve star TW Piscis Austrini, the wide (∼0.3 pc) companion to the A4V star Fomalhaut. We combined absolute astrometry from Hipparcos and Gaia with literature radial velocity measurements and dedicated high-contrast imaging observations o…
Radial Velocities, Space Motions, and Nearby Young Moving Group Memberships of Eleven Candidate Young Brown Dwarfs
Alam, Munazza K.; Faherty, Jacqueline K.; Cruz, Kelle L. +5 more
We present new radial velocity (RV) measurements for 11 candidate young very-low-mass stars and brown dwarfs, with spectral types from M7 to L7. Candidate young objects were identified by features indicative of low surface gravity in their optical and/or near-infrared spectra. RV measurements are derived from high-resolution (R =λ/Δλ = 20,000) J-b…
Astrometry and Occultation Predictions to Trans-Neptunian and Centaur Objects Observed within the Dark Energy Survey
Smith, M.; Abbott, T. M. C.; Abdalla, F. B. +60 more
Trans-Neptunian objects (TNOs) are a source of invaluable information to access the history and evolution of the outer solar system. However, observing these faint objects is a difficult task. As a consequence, important properties such as size and albedo are known for only a small fraction of them. Now, with the results from deep sky surveys and …
WASP-190b: Tomographic Discovery of a Transiting Hot Jupiter
Bouchy, F.; Queloz, D.; Ségransan, D. +22 more
We report the discovery of WASP-190b, an exoplanet on a 5.37 day orbit around a mildly evolved F6 IV-V star with V = 11.7, {T}eff} = 6400 ± 100 K, M * = 1.35 ± 0.05 M ⊙, and R * = 1.6 ± 0.1 R ⊙. The planet has a radius of R P = 1.15 ± 0.09 R Jup and a mass of M P
Stellar Parameters for Pulsating B-star Candidates in the Kepler Field
McSwain, M. Virginia; Hanes, Richard J.; Waskie, Steven +3 more
The field of asteroseismology has enjoyed a large swath of data coming from recent missions (e.g., CoRoT, Kepler, K2). This wealth of new data has allowed the field to expand beyond the previous limitation of a few extremely bright and evolved stars. Asteroseismology relies on accurate surface measurements for boundary conditions, but the predicte…
Two Long-period Cataclysmic Variable Stars: ASASSN-14ho and V1062 Cyg
Thorstensen, John R.; Paterson, Kerry; Hviding, Raphael E. +5 more
We report spectroscopy and photometry of the cataclysmic variable stars ASASSN-14ho and V1062 Cyg. Both are dwarf novae with spectra dominated by their secondary stars, which we classify approximately as K4 and M0.5, respectively. Their orbital periods, determined mostly from the secondary stars’ radial velocities, proved to be nearly identical, r…
Comparison of the PPMXL and UCAC5 Catalogs with the Gaia DR2
Liu, N.; Zhu, Z.; Liu, J. -C. +3 more
Astrometric ground-based catalogs usually suffer from varied systematic errors. These systematic errors were hard to detect because there was no independent reference catalog complete to very faint limiting magnitudes (∼20 mag). This situation has changed since the second data release of the Gaia mission (Gaia DR2). We aim to investigate positions…