Search Publications

The High-energy Spectrum of the Nearby Planet-hosting Inactive Mid-M Dwarf LHS 3844
DOI: 10.3847/1538-3881/abfa1c Bibcode: 2021AJ....162...10D

Youngblood, Allison; Charbonneau, David; Kempton, Eliza M. -R. +5 more

To fully characterize the atmospheres, or lack thereof, of terrestrial exoplanets, we must include the high-energy environments provided by their host stars. The nearby mid-M dwarf LHS 3844 hosts a terrestrial world that lacks a substantial atmosphere. We present a time-series UV spectrum of LHS 3844 from 1131 to 3215 Å captured by HST/COS. We det…

2021 The Astronomical Journal
Gaia eHST 17
Linking nearby stellar streams to more distant halo overdensities
DOI: 10.1051/0004-6361/202141015 Bibcode: 2021A&A...654A..15B

Helmi, A.; Balbinot, E.

Context. It has recently been shown that the halo near the Sun contains several kinematic substructures associated with past accretion events. For the more distant halo, there is evidence of large-scale density variations - in the form of stellar clouds or overdensities.
Aims: We study the link between the local halo kinematic groups and thre…

2021 Astronomy and Astrophysics
Gaia 17
Testing the Limits of Precise Subgiant Characterization with APOGEE and Gaia: Opening a Window to Unprecedented Astrophysical Studies
DOI: 10.3847/1538-4357/abf8ba Bibcode: 2021ApJ...915...19G

Stassun, Keivan G.; van Saders, Jennifer L.; Beaton, Rachael L. +6 more

Given their location on the Hertzsprung-Russell (H-R) diagram, thoroughly characterized subgiant stars can place stringent constraints on a wide range of astrophysical problems. Accordingly, they are prime asteroseismic targets for the Transiting Exoplanet Survey Satellite (TESS) mission. In this work, we infer stellar properties for a sample of 3…

2021 The Astrophysical Journal
Gaia 17
The effect of varying porosity and inhomogeneities of the surface dust layer on the modelling of comet gas production
DOI: 10.1093/mnras/staa3735 Bibcode: 2021MNRAS.501.2635S

Skorov, Yuri; Reshetnyk, Volodymyr; Blum, Jürgen +3 more

We study how uncertainties in knowledge of the microstructure of the porous dust surface layer affect our estimates of effective gas production of comet 67P/Churyumov-Gerasimenko. We analyse the transport properties (distribution of free paths, mean pore size, permeability) for random densely packed porous layers. Bimodal layers, as well as variou…

2021 Monthly Notices of the Royal Astronomical Society
Rosetta 17
Asteroseismology of overmassive, undermassive, and potential past members of the open cluster NGC 6791
DOI: 10.1093/mnras/stab2183 Bibcode: 2021MNRAS.507..496B

Miglio, A.; Brogaard, K.; Arentoft, T. +1 more

We perform an asteroseismic investigation of giant stars in the field of NGC 6791 with previous indications of atypical evolution. The analysis uses observations from Kepler and Gaia in combination with ground-based photometry, a literature radial-velocity study, and measurements of eclipsing binaries in the cluster. We derive mass, radius, effect…

2021 Monthly Notices of the Royal Astronomical Society
Gaia 17
Distances to molecular clouds in the second Galactic quadrant
DOI: 10.1051/0004-6361/202039768 Bibcode: 2021A&A...645A.129Y

Wang, Hongchi; Xu, Ye; Su, Yang +5 more

We present distances to 76 medium-sized molecular clouds and an extra large-scale molecular cloud in the second Galactic quadrant (104. °75 < l < 150. °25 and |b| < 5. °25), 73 of which are accurately measured for the first time. Molecular cloud samples are drawn from l-b-V space (- 95 < VLSR < 25 km s-1) with …

2021 Astronomy and Astrophysics
Gaia 17
Solar wind Alfvénicity during solar cycle 23 and 24. Perspective for future observations with Parker Solar Probe and Solar Orbiter
DOI: 10.1051/0004-6361/202140600 Bibcode: 2021A&A...654A.111D

Bruno, R.; Lepri, S. T.; Zhao, L. +5 more

Context. Alfvénic fluctuations are ubiquitous features observed in solar wind, especially in the inner heliosphere. However, strong Alfvénic fluctuations are recovered in the near-Earth solar wind too, mainly in fast streams, but also in some cases in slow wind intervals, as highlighted in recent studies.
Aims: The present study focuses on a …

2021 Astronomy and Astrophysics
SolarOrbiter 16
The eclipsing binary systems with δ Scuti component - I. KIC 10661783
DOI: 10.1093/mnras/stab1597 Bibcode: 2021MNRAS.505.3206M

Daszyńska-Daszkiewicz, J.; Szewczuk, W.; Miszuda, A.

We present a comprehensive study of the eclipsing binary system KIC 10661783. The analysis of the whole Kepler light curve, corrected for the binary effects, reveals a rich oscillation spectrum with 590 significant frequency peaks, 207 of which are independent. In addition to typical δ Scuti (δ Sct) frequencies, we find small-amplitude signals in …

2021 Monthly Notices of the Royal Astronomical Society
Gaia 16
ALMA and MUSE observations reveal a quiescent multi-phase circumgalactic medium around the z ≃ 3.6 radio galaxy 4C 19.71
DOI: 10.1051/0004-6361/201935237 Bibcode: 2021A&A...645A.120F

Lehnert, Matthew D.; De Breuck, Carlos; Vernet, Joël +2 more

We present MUSE at VLT imaging spectroscopy of rest-frame ultraviolet emission lines and ALMA observations of the [C I] 3P1-3P0 emission line, probing both the ionized and diffuse molecular medium around the radio galaxy 4C 19.71 at z ≃ 3.6. This radio galaxy has extended Lyα emission over a region ∼100 …

2021 Astronomy and Astrophysics
Gaia 16
On the Use of Field RR Lyrae as Galactic Probes. V. Optical and Radial Velocity Curve Templates
DOI: 10.3847/1538-4357/ac1074 Bibcode: 2021ApJ...919...85B

Lemasle, B.; Latour, M.; Zoccali, M. +29 more

We collected the largest spectroscopic catalog of RR Lyrae (RRLs) including ≈20,000 high-, medium-, and low-resolution spectra for ≈10,000 RRLs. We provide the analytical forms of radial velocity curve (RVC) templates. These were built using 36 RRLs (31 fundamental-split into three period bins-and five first-overtone pulsators) with well-sampled R…

2021 The Astrophysical Journal
Gaia 16