Search Publications

Determination of the Venus eddy diffusion profile from CO and CO2 profiles using SOIR/Venus Express observations
DOI: 10.1016/j.icarus.2021.114388 Bibcode: 2021Icar..36114388M

Vandaele, A. C.; Robert, S.; Mahieux, A. +6 more

We present a study of the SOIR/Venus Express CO2 and CO profiles in order to constrain the eddy diffusion profile in the Venus mesosphere (80 to 130 km of altitude). We compute the mean number density profile of both species, and the hydrostatic temperature based on the CO2 mean density profile. We use a 1D-photochemical/diff…

2021 Icarus
VenusExpress 5
Morphology of Jupiter's Polar Auroral Bright Spot Emissions via Juno UVS Observations
DOI: 10.1029/2020JA028586 Bibcode: 2021JGRA..12628586H

Bonfond, B.; Vogt, M. F.; Gérard, J. -C. +12 more

Since 2016, the Juno UVS (Ultraviolet Spectrograph) instrument has been taking spectral images of Jupiter's auroras in their full extent, including the nightside, which cannot be viewed from Earth. We present a systematic analysis of features in Jupiter's polar auroras called auroral bright spots, which were observed by Juno UVS during the first 2…

2021 Journal of Geophysical Research (Space Physics)
eHST 5
Preview of Comet C/2021 A1 (Leonard) and Its Encounter with Venus
DOI: 10.3847/1538-3881/ac19ba Bibcode: 2021AJ....162..194Z

Zhang, Qicheng; Farnham, Tony L.; Knight, Matthew M. +2 more

Long-period comet C/2021 A1 (Leonard) will approach Venus to within 0.029 au on 2021 December 18 and may subsequently graze the planet with its dust trail less than 2 days later. We observed C/2021 A1 with the Lowell Discovery Telescope on 2021 January 13 and March 3, as well as with the Palomar Hale Telescope on 2021 March 20, while the comet was…

2021 The Astronomical Journal
Gaia 5
HAT-P-68b: A Transiting Hot Jupiter around a K5 Dwarf Star
DOI: 10.3847/1538-3881/abc700 Bibcode: 2021AJ....161...64L

Torres, Guillermo; Bieryla, Allyson; Latham, David W. +23 more

We report the discovery by the ground-based Hungarian-made Automated Telescope Network (HATNet) survey of the transiting exoplanet HAT-P-68b, which has a mass of 0.724 ± 0.043 MJ, and radius of 1.072 ± 0.012 RJ. The planet is in a circular P = 2.2984 day orbit around a moderately bright V = 13.937 ± 0.030 magnitude K-dwarf st…

2021 The Astronomical Journal
Gaia 5
The first photometric analysis of the totally eclipsing contact binary V811 Cep
DOI: 10.1088/1674-4527/21/8/193 Bibcode: 2021RAA....21..193G

Li, Kai; Gao, Xing; Liu, Yuan +1 more

The first photometric analysis of V811 Cep was carried out. The first complete light curves of V, R and I bands are given. The analysis was carried out by the Wilson-Devinney (W-D) program, and the results show that V811 Cep is a median-contact binary (f = 33.9(±4.9)%) with a mass ratio of 0.285. It is a W-subtype contact binary, that is, the comp…

2021 Research in Astronomy and Astrophysics
Gaia 5
Constraints on the dust extinction law of the Galaxy with Swift/UVOT, Gaia, and 2MASS
DOI: 10.1093/mnras/stab1270 Bibcode: 2021MNRAS.505..283F

Cropper, Mark; Charlot, Stéphane; Kawata, Daisuke +6 more

We explore variations of the dust extinction law of the Milky Way by selecting stars from the Swift/UVOT Serendipitous Source Catalogue, cross-matched with Gaia DR2 and 2MASS to produce a sample of 10 452 stars out to ~4 kpc with photometry covering a wide spectral window. The near ultraviolet passbands optimally encompass the 2175 Å bump, so that…

2021 Monthly Notices of the Royal Astronomical Society
Gaia 5
Similarities of magnetoconvection in the umbra and in the penumbra of sunspots
DOI: 10.1051/0004-6361/202141440 Bibcode: 2021A&A...655A..61L

Solanki, S. K.; Lagg, A.; Löptien, B. +1 more

Context. It is unclear why there is a rather sharp boundary in sunspots between the umbra and the penumbra. Both regions exhibit magnetoconvection, which manifests in penumbral filaments in the penumbra and in umbral dots in the umbra.
Aims: Here we compare the physical properties of umbral dots and penumbral filaments. Our goal is to underst…

2021 Astronomy and Astrophysics
Hinode 5
Ancient and present surface evolution processes in the Ash region of comet 67P/Churyumov-Gerasimenko
DOI: 10.1051/0004-6361/202140516 Bibcode: 2021A&A...649A..82B

Jorda, L.; Groussin, O.; Bouley, S. +3 more


Aims: The Rosetta mission provided us with detailed data of the surface of the nucleus of comet 67P/Churyumov-Gerasimenko. In order to better understand the physical processes associated with the comet activity and the surface evolution of its nucleus, we performed a detailed comparative morphometrical analysis of two depressions located in t…

2021 Astronomy and Astrophysics
Rosetta 5
Revealing Ionization Conditions of Sz 102 with Spatially Resolved [Ne III] Microjets
DOI: 10.3847/1538-4357/abd626 Bibcode: 2021ApJ...909..196L

Herczeg, Gregory J.; Liu, Chun-Fan; Shang, Hsien +1 more

Forbidden neon emission lines from small-scale microjets can probe high-energy processes in low-mass young stellar systems. We obtained spatially resolved [Ne III] spectra in the microjets from the classical T Tauri Star Sz 102 using the Hubble Space Telescope Imaging Spectrograph at a spatial resolution of ∼0"1. The blueshifted and redshifted [Ne…

2021 The Astrophysical Journal
eHST 5
X-ray emission of Seyfert 2 galaxy MCG-01-24-12
DOI: 10.1051/0004-6361/202039984 Bibcode: 2021A&A...647A.102M

Bianchi, S.; Dadina, M.; Braito, V. +7 more

We present a detailed X-ray spectral analysis of the nearby Seyfert 2 galaxy MCG-01-24-12 based on a multi-epoch data set. Data were obtained with different X-ray satellites, namely XMM-Newton, NuSTAR, Swift, and Chandra, and cover different time intervals, from a few days to years. From 2006 to 2013 the source had a 2-10 keV flux of ∼1.5 × 10

2021 Astronomy and Astrophysics
XMM-Newton 5