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The changing face of AU Mic b: stellar spots, spin-orbit commensurability, and transit timing variations as seen by CHEOPS and TESS
DOI: 10.1051/0004-6361/202140345 Bibcode: 2021A&A...654A.159S

Guterman, P.; Alonso, R.; Deleuil, M. +78 more

AU Mic is a young planetary system with a resolved debris disc showing signs of planet formation and two transiting warm Neptunes near mean-motion resonances. Here we analyse three transits of AU Mic b observed with the CHaracterising ExOPlanet Satellite (CHEOPS), supplemented with sector 1 and 27 Transiting Exoplanet Survey Satellite (TESS) photo…

2021 Astronomy and Astrophysics
CHEOPS Gaia 54
Exploring the Galaxy's halo and very metal-weak thick disc with SkyMapper and Gaia DR2
DOI: 10.1093/mnras/staa3417 Bibcode: 2021MNRAS.503.2539C

Schmidt, B. P.; Da Costa, G. S.; Milone, A. P. +16 more

In this work, we combine spectroscopic information from the SkyMapper survey for Extremely Metal-Poor stars and astrometry from Gaia DR2 to investigate the kinematics of a sample of 475 stars with a metallicity range of $-6.5 \le \rm [Fe/H] \le -2.05$ dex. Exploiting the action map, we identify 16 and 40 stars dynamically consistent with the Gaia …

2021 Monthly Notices of the Royal Astronomical Society
Gaia 54
Diversity of nuclear star cluster formation mechanisms revealed by their star formation histories
DOI: 10.1051/0004-6361/202140644 Bibcode: 2021A&A...650A.137F

Hilker, M.; Pinna, F.; de Zeeuw, P. T. +15 more

Nuclear star clusters (NSCs) are the densest stellar systems in the Universe and are found in the centres of all types of galaxies. They are thought to form via mergers of star clusters such as ancient globular clusters (GCs) that spiral to the centre as a result of dynamical friction or through in situ star formation directly at the galaxy centre…

2021 Astronomy and Astrophysics
eHST 54
Dynamically Tagged Groups of Very Metal-poor Halo Stars from the HK and Hamburg/ESO Surveys
DOI: 10.3847/1538-4357/abcb87 Bibcode: 2021ApJ...907...10L

Beers, Timothy C.; Lee, Young Sun; Placco, Vinicius M. +13 more

We analyze the dynamical properties of ∼1500 very metal-poor (VMP; [Fe/H] ≲ -2.0) halo stars, based primarily on medium-resolution spectroscopic data from the HK and Hamburg/ESO surveys. These data, collected over the past 30 yr, are supplemented by a number of calibration stars and other small samples, along with astrometric information from Gaia…

2021 The Astrophysical Journal
Gaia 54
Abundance measurements of H2O and carbon-bearing species in the atmosphere of WASP-127b confirm its supersolar metallicity
DOI: 10.1093/mnras/staa3116 Bibcode: 2021MNRAS.500.4042S

Deming, Drake; Nikolov, Nikolay; Carter, Aarynn L. +14 more

The chemical abundances of exoplanet atmospheres may provide valuable information about the bulk compositions, formation pathways, and evolutionary histories of planets. Exoplanets with large, relatively cloud-free atmospheres, and which orbit bright stars provide the best opportunities for accurate abundance measurements. For this reason, we meas…

2021 Monthly Notices of the Royal Astronomical Society
eHST 54
A comprehensive reanalysis of Spitzer's 4.5 µm phase curves, and the phase variations of the ultra-hot Jupiters MASCARA-1b and KELT-16b
DOI: 10.1093/mnras/stab1027 Bibcode: 2021MNRAS.504.3316B

Fortney, Jonathan J.; Stevenson, Kevin B.; Désert, Jean-Michel +12 more

We have developed an open-source pipeline for the analysis of Spitzer/IRAC channel 1 and 2 time-series photometry, incorporating some of the most popular decorrelation methods. We applied this pipeline to new phase curve observations of ultra-hot Jupiters MASCARA-1b and KELT-16b, and we performed the first comprehensive reanalysis of 15 phase curv…

2021 Monthly Notices of the Royal Astronomical Society
Gaia 54
Constraining stellar evolution theory with asteroseismology of γ Doradus stars using deep learning. Stellar masses, ages, and core-boundary mixing
DOI: 10.1051/0004-6361/202039543 Bibcode: 2021A&A...650A..58M

Aerts, C.; Van Reeth, T.; Mombarg, J. S. G.

Context. The efficiency of the transport of angular momentum and chemical elements inside intermediate-mass stars lacks proper calibration, thereby introducing uncertainties on a star's evolutionary pathway. Improvements require better estimation of stellar masses, evolutionary stages, and internal mixing properties.
Aims: Our aim was to deve…

2021 Astronomy and Astrophysics
Gaia 54
The BepiColombo Planetary Magnetometer MPO-MAG: What Can We Learn from the Hermean Magnetic Field?
DOI: 10.1007/s11214-021-00822-x Bibcode: 2021SSRv..217...52H

Balogh, A.; Glassmeier, K. -H.; Nakamura, R. +29 more

The magnetometer instrument MPO-MAG on-board the Mercury Planetary Orbiter (MPO) of the BepiColombo mission en-route to Mercury is introduced, with its instrument design, its calibration and scientific targets. The instrument is comprised of two tri-axial fluxgate magnetometers mounted on a 2.9 m boom and are 0.8 m apart. They monitor the magnetic…

2021 Space Science Reviews
BepiColombo 54
Measuring fundamental jet properties with multiwavelength fast timing of the black hole X-ray binary MAXI J1820+070
DOI: 10.1093/mnras/stab820 Bibcode: 2021MNRAS.504.3862T

Maccarone, T. J.; Dhillon, V. S.; Gandhi, P. +9 more

We present multiwavelength fast timing observations of the black hole X-ray binary MAXI J1820+070 (ASASSN-18ey), taken with the Karl G. Jansky Very Large Array (VLA), Atacama Large Millimeter/Sub-Millimeter Array (ALMA), Very Large Telescope (VLT), New Technology Telescope (NTT), Neutron Star Interior Composition Explorer (NICER), and XMM-Newton. …

2021 Monthly Notices of the Royal Astronomical Society
Gaia XMM-Newton 53
Einstein@Home discovery of the gamma-ray millisecond pulsar PSR J2039-5617 confirms its predicted redback nature
DOI: 10.1093/mnras/staa3484 Bibcode: 2021MNRAS.502..915C

Dhillon, V. S.; Guillemot, L.; Harding, A. K. +19 more

The Fermi Large Area Telescope gamma-ray source 3FGL J2039.6-5618 contains a periodic optical and X-ray source that was predicted to be a 'redback' millisecond pulsar (MSP) binary system. However, the conclusive identification required the detection of pulsations from the putative MSP. To better constrain the orbital parameters for a directed sear…

2021 Monthly Notices of the Royal Astronomical Society
Gaia XMM-Newton 53