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CHEOPS observations of the HD 108236 planetary system: a fifth planet, improved ephemerides, and planetary radii
DOI: 10.1051/0004-6361/202039608 Bibcode: 2021A&A...646A.157B

Guterman, P.; Alonso, R.; Deleuil, M. +106 more

Context. The detection of a super-Earth and three mini-Neptunes transiting the bright (V = 9.2 mag) star HD 108236 (also known as TOI-1233) was recently reported on the basis of TESS and ground-based light curves.
Aims: We perform a first characterisation of the HD 108236 planetary system through high-precision CHEOPS photometry and improve t…

2021 Astronomy and Astrophysics
CHEOPS Gaia 68
Discovery of magnetic fields along stacked cosmic filaments as revealed by radio and X-ray emission
DOI: 10.1093/mnras/stab1301 Bibcode: 2021MNRAS.505.4178V

Vazza, F.; West, J. L.; Galvin, T. J. +5 more

Diffuse filaments connect galaxy clusters to form the cosmic web. Detecting these filaments could yield information on the magnetic field strength, cosmic ray population, and temperature of intercluster gas; yet, the faint and large-scale nature of these bridges makes direct detections very challenging. Using multiple independent all-sky radio and…

2021 Monthly Notices of the Royal Astronomical Society
AKARI 68
Milky Way spiral arms from open clusters in Gaia EDR3
DOI: 10.1051/0004-6361/202039751 Bibcode: 2021A&A...652A.162C

Castro-Ginard, A.; Jordi, C.; Luri, X. +7 more

Context. The physical processes driving the formation of Galactic spiral arms are still under debate. Studies using open clusters favour the description of the Milky Way spiral arms as long-lived structures following the classical density wave theory. Current studies comparing the Gaia DR2 field stars kinematic information of the solar neighbourho…

2021 Astronomy and Astrophysics
Gaia 67
The X-SHOOTER Lyman α survey at z = 2 (XLS-z2) I: what makes a galaxy a Lyman α emitter?
DOI: 10.1093/mnras/stab1304 Bibcode: 2021MNRAS.505.1382M

Hayes, Matthew; Schaerer, Daniel; Sobral, David +9 more

We present the first results from the X-SHOOTER Lyman α survey at z = 2 (XLS-z2). XLS-z2 is a deep spectroscopic survey of 35 Lyman α emitters (LAEs) utilizing ≈90 h of exposure time with Very Large Telescope/X-SHOOTER and covers rest-frame Ly α to H α emission with R ≈ 4000. We present the sample selection, the observations, and the data reductio…

2021 Monthly Notices of the Royal Astronomical Society
Gaia eHST 67
A unique hot Jupiter spectral sequence with evidence for compositional diversity
DOI: 10.1038/s41550-021-01455-4 Bibcode: 2021NatAs...5.1224M

Fortney, Jonathan J.; Sing, David K.; López-Morales, Mercedes +11 more

The emergent spectra of close-in, giant exoplanets (`hot Jupiters') are expected to be distinct from those of self-luminous objects with similar effective temperatures because hot Jupiters are primarily heated from above by their host stars rather than internally from the release of energy from their formation1. Theoretical models predi…

2021 Nature Astronomy
eHST 67
BAT AGN Spectroscopic Survey. XX. Molecular Gas in Nearby Hard-X-Ray-selected AGN Galaxies
DOI: 10.3847/1538-4365/abcbfe Bibcode: 2021ApJS..252...29K

Lamperti, Isabella; Schawinski, Kevin; Saintonge, Amelie +23 more

We present the host-galaxy molecular gas properties of a sample of 213 nearby (0.01 < z < 0.05) hard-X-ray-selected active galactic nucleus (AGN) galaxies, drawn from the 70-month catalog of Swift's Burst Alert Telescope (BAT), with 200 new CO(2-1) line measurements obtained with the James Clerk Maxwell Telescope and the Atacama Pathfinder E…

2021 The Astrophysical Journal Supplement Series
Herschel 67
Detection and Bulk Properties of the HR 8799 Planets with High-resolution Spectroscopy
DOI: 10.3847/1538-3881/ac1349 Bibcode: 2021AJ....162..148W

Knutson, Heather; Duchêne, Gaspard; Fitzgerald, Michael P. +49 more

Using the Keck Planet Imager and Characterizer, we obtained high-resolution (R ~ 35,000) K-band spectra of the four planets orbiting HR 8799. We clearly detected H2O and CO in the atmospheres of HR 8799 c, d, and e, and tentatively detected a combination of CO and H2O in b. These are the most challenging directly imaged exopl…

2021 The Astronomical Journal
Gaia 67
Self-consistent Stellar Radial Velocities from LAMOST Medium-resolution Survey DR7
DOI: 10.3847/1538-4365/ac0834 Bibcode: 2021ApJS..256...14Z

Tian, Hao; Zong, Weikai; Fu, Jian-Ning +12 more

Radial velocity (RV) is among the most fundamental physical quantities obtainable from stellar spectra and is rather important in the analysis of time-domain phenomena. LAMOST Medium-resolution Survey (MRS) DR7 contains five million single-exposure stellar spectra with spectral resolution R ~ 7500. However, the temporal variation of the RV zero-po…

2021 The Astrophysical Journal Supplement Series
Gaia 67
New insight into the magnetism of degenerate stars from the analysis of a volume-limited sample of white dwarfs
DOI: 10.1093/mnras/stab2046 Bibcode: 2021MNRAS.507.5902B

Bagnulo, S.; Landstreet, J. D.

Many stars evolve into magnetic white dwarfs (MWDs), and observations may help to understand when the magnetic field appears at the stellar surface, if and how it evolves during the cooling phase, and, above all, what are the mechanisms that generate it. After obtaining new spectropolarimetric observations and combining them with previous literatu…

2021 Monthly Notices of the Royal Astronomical Society
Gaia eHST 67
Tree-ring structure of Galactic bar resonance
DOI: 10.1093/mnras/stab1094 Bibcode: 2021MNRAS.505.2412C

Schönrich, Ralph; Chiba, Rimpei

Galaxy models have long predicted that galactic bars slow down by losing angular momentum to their postulated dark haloes. When the bar slows down, resonance sweeps radially outwards through the galactic disc while growing in volume, thereby sequentially capturing new stars at its surface/separatrix. Since trapped stars conserve their action of li…

2021 Monthly Notices of the Royal Astronomical Society
Gaia 66