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Direct Measurement of the Solar-wind Taylor Microscale Using MMS Turbulence Campaign Data
DOI: 10.3847/1538-4357/ab9ebe Bibcode: 2020ApJ...899...63B

Strangeway, Robert J.; Russell, Christopher T.; Chasapis, Alexandros +7 more

Using the novel Magnetospheric Multiscale (MMS) mission data accumulated during the 2019 MMS Solar Wind Turbulence Campaign, we calculate the Taylor microscale (λT) of the turbulent magnetic field in the solar wind. The Taylor microscale represents the onset of dissipative processes in classical turbulence theory. However, an accurate e…

2020 The Astrophysical Journal
Cluster 23
Plasma characterization at comet 67P between 2 and 4 AU from the Sun with the RPC-MIP instrument
DOI: 10.1051/0004-6361/202037571 Bibcode: 2020A&A...638A.124W

Henri, Pierre; Vallières, Xavier; Deca, Jan +2 more

The plasma of comet 67P/Churyumov-Gerasimenko is analyzed based on the RPC-MIP mutual impedance probe data of the Rosetta mission. Numerical simulations of the RPC-MIP instrumental response considering two populations of electrons were fit on experimental responses acquired from January to September 2016 to extract the electron densities and tempe…

2020 Astronomy and Astrophysics
Rosetta 23
A multi-chord stellar occultation by the large trans-Neptunian object (174567) Varda
DOI: 10.1051/0004-6361/202038526 Bibcode: 2020A&A...643A.125S

Berthier, J.; Carry, B.; Souami, D. +41 more

Context. We present results from the first recorded stellar occultation by the large trans-Neptunian object (174567) Varda that was observed on September 10, 2018. Varda belongs to the high-inclination dynamically excited population, and has a satellite, Ilmarë, which is half the size of Varda.
Aims: We determine the size and albedo of Varda …

2020 Astronomy and Astrophysics
Gaia eHST 23
Cloud Atlas: Weak Color Modulations Due to Rotation in the Planetary-mass Companion GU Psc b and 11 Other Brown Dwarfs
DOI: 10.3847/1538-3881/ab5f59 Bibcode: 2020AJ....159..125L

Schneider, Glenn; Apai, Dániel; Marley, Mark +10 more

Among the greatest challenges in understanding ultracool brown dwarf and exoplanet atmospheres is the evolution of cloud structure as a function of temperature and gravity. In this study, we present the rotational modulations of GU Psc b—a rare mid-T spectral type planetary-mass companion at the end of the L/T spectral type transition. Based on th…

2020 The Astronomical Journal
Gaia eHST 23
TIC 278825952: a triply eclipsing hierarchical triple system with the most intrinsically circular outer orbit
DOI: 10.1093/mnras/staa2762 Bibcode: 2020MNRAS.498.6034M

Mitnyan, T.; Pál, A.; Maxted, P. F. L. +2 more

We report the discovery of a compact triply eclipsing triple star system in the southern continuous viewing zone of the TESS space telescope. TIC 278825952 is a previously known, but unstudied circular eclipsing binary with a period of 4.781 d with a tertiary component in a wider, circular orbit of 235.55-d period that was found from three sets of…

2020 Monthly Notices of the Royal Astronomical Society
Gaia 23
Inverse-Compton scattering in the resolved jet of the high-redshift quasar PKS J1421-0643
DOI: 10.1093/mnras/staa1975 Bibcode: 2020MNRAS.497..988W

Siemiginowska, A.; Birkinshaw, M.; Worrall, D. M. +3 more

Despite the fact that kpc-scale inverse-Compton (iC) scattering of cosmic microwave background (CMB) photons into the X-ray band is mandated, proof of detection in resolved quasar jets is often insecure. High redshift provides favourable conditions due to the increased energy density of the CMB, and it allows constraints to be placed on the radio …

2020 Monthly Notices of the Royal Astronomical Society
eHST 23
Searching for ZZ Ceti White Dwarfs in the Gaia Survey
DOI: 10.3847/1538-3881/abbe20 Bibcode: 2020AJ....160..252V

Bergeron, P.; Vincent, Olivier; Lafrenière, David

The Gaia satellite recently released parallax measurements for ∼260,000 high-confidence white dwarf candidates, allowing for precise measurements of their physical parameters. By combining these parallaxes with Pan-STARRS and u-band photometry, we measured the effective temperature and stellar mass for all white dwarfs in the Northern Hemisphere w…

2020 The Astronomical Journal
Gaia 23
Evidence of Systematic Errors in Spitzer Microlens Parallax Measurements
DOI: 10.3847/1538-3881/abaf4e Bibcode: 2020AJ....160..177K

Bennett, David P.; Koshimoto, Naoki

The microlensing parallax campaign with the Spitzer space telescope aims to measure masses and distances of microlensing events seen toward the Galactic bulge, with a focus on planetary microlensing events. The hope is to measure how the distribution of planets depends on position within the Galaxy. In this paper, we compare 50 microlens parallax …

2020 The Astronomical Journal
Gaia 23
Diagonal Ridge Pattern of Different Age Populations Found in Gaia-DR2 with LAMOST Main-sequence Turnoff and OB-type Stars
DOI: 10.3847/1538-4357/abb3c8 Bibcode: 2020ApJ...902...70W

Wang, H. -F.; López-Corredoira, M.; Huang, Y. +5 more

We revisit the diagonal ridge feature (diagonal distributions in the R, vφ plane) found in Gaia and present a timing analysis for it between Galactocentric distances of R = 7.5 and 12 kpc, using main-sequence turnoff and OB stars selected from the LAMOST Galactic spectroscopic surveys. We recover the ridge pattern in the R-vφ

2020 The Astrophysical Journal
Gaia 23
The K2 and TESS Synergy. I. Updated Ephemerides and Parameters for K2-114, K2-167, K2-237, and K2-261
DOI: 10.3847/1538-3881/aba964 Bibcode: 2020AJ....160..209I

Barclay, Thomas; Vanderburg, Andrew; Bieryla, Allyson +30 more

Although the Transiting Exoplanet Survey Satellite (TESS) primary mission observed the northern and southern ecliptic hemispheres, generally avoiding the ecliptic, and the Kepler space telescope during the K2 mission could only observe near the ecliptic, many of the K2 fields extend far enough from the ecliptic plane that sections overlap with TES…

2020 The Astronomical Journal
Gaia 23