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New luminous blue variable candidates in NGC 4736
DOI: 10.1093/mnrasl/sly241 Bibcode: 2019MNRAS.484L..24S

Vinokurov, A.; Solovyeva, Y.; Atapin, K. +8 more

We have found three new luminous blue variable (LBV) candidates in the star-forming galaxy NGC 4736. They show typical well-known LBV spectra, broad and strong hydrogen lines, He I lines, many Fe II lines, and forbidden [Fe II] and [Fe III]. Using archival Hubble Space Telescope and ground-based telescope data, we have estimated the bolometric mag…

2019 Monthly Notices of the Royal Astronomical Society
eHST 13
Star formation in far-IR AGN and non-AGN galaxies in the green valley - II. Morphological analysis
DOI: 10.1093/mnras/stz434 Bibcode: 2019MNRAS.485..452M

Pović, Mirjana; Väisänen, Petri; Mahoro, Antoine +2 more

This paper studies morphological properties of 103 green valley FIR active and 2609 non-active galaxies presented in Mahoro, Pović & Nkundabakura (2017). The photometric data from the COSMOS survey were used, and the morphological parameters, such as Abraham and Conselice-Bershady concentration indices, Gini, M20 moment of light, and asymmetry…

2019 Monthly Notices of the Royal Astronomical Society
eHST 13
Chemical analysis of K giants in the young open cluster NGC 2345
DOI: 10.1093/mnras/sty2991 Bibcode: 2019MNRAS.482.5275H

Pereira, C. B.; Holanda, N.; Drake, N. A.

We present results for the elemental abundances of five K giants of the young open cluster NGC 2345. The atmospheric parameters of the studied giants and their chemical abundances were determined using high-resolution optical spectroscopy. In this study, we determine abundances of light elements (Li, C, N), light odd-Z elements (Na, Al), α-element…

2019 Monthly Notices of the Royal Astronomical Society
Gaia 13
Detailed study of the Milky Way globular cluster Laevens 3
DOI: 10.1093/mnras/stz2592 Bibcode: 2019MNRAS.490.1498L

Martin, Nicolas; Ibata, Rodrigo A.; Mackey, Dougal +4 more

We present a photometric and spectroscopic study of the Milky Way satellite Laevens 3. Using MegaCam/Canada-France-Hawaii Telescope g and i photometry and Keck II/DEIMOS multi-object spectroscopy, we refine the structural and stellar properties of the system. The Laevens 3 colour-magnitude diagram shows that it is quite metal-poor, old (13.0 ± 1.0…

2019 Monthly Notices of the Royal Astronomical Society
Gaia 13
Surface evolution of the Anhur region on comet 67P/Churyumov-Gerasimenko from high-resolution OSIRIS images
DOI: 10.1051/0004-6361/201834824 Bibcode: 2019A&A...630A..13F

Jorda, L.; Lamy, P. L.; Bertaux, J. -L. +34 more

Context. The southern hemisphere of comet 67P/Churyumov-Gerasimenko (67P) became observable by the Rosetta mission in March 2015, a few months before cometary southern vernal equinox. The Anhur region in the southern part of the comet's larger lobe was found to be highly eroded, enriched in volatiles, and highly active.
Aims: We analyze high-…

2019 Astronomy and Astrophysics
Rosetta 13
Seasonal variations in source regions of the dust jets on comet 67P/Churyumov-Gerasimenko
DOI: 10.1051/0004-6361/201732094 Bibcode: 2019A&A...630A..17L

Jorda, L.; Lara, L. M.; Bertaux, J. -L. +43 more


Aims: We investigate the surface distribution of the source regions of dust jets on comet 67P/Churyumov-Gerasimenko as a function of time.
Methods: The dust jet source regions were traced by the comprehensive imaging data set provided by the OSIRIS scientific camera.
Results: We show in detail how the projected footpoints of the dus…

2019 Astronomy and Astrophysics
Rosetta 13
Spectral Signatures of Adiabatic Electron Acceleration at Saturn Through Corotation Drift Cancelation
DOI: 10.1029/2019GL084113 Bibcode: 2019GeoRL..4610240S

Krupp, N.; Roussos, E.; Zong, Q. G. +3 more

The energetic electron spectra of Saturn's radiation belts are studied using Cassini's 13 years of measurements by the Magnetosphere Imaging Instrument/Low Energy Magnetospheric Measurement System detector. We find that between L shells (L) of 10 and 4.5 the differential flux spectrum of 0.3- to 1.6-MeV electrons evolves from a single power law to…

2019 Geophysical Research Letters
Cassini 13
Onset and Evolution of the Oblique, Resonant Electron Firehose Instability in the Expanding Solar Wind Plasma
DOI: 10.3847/1538-4357/ab3e40 Bibcode: 2019ApJ...883..146I

Velli, Marco; Innocenti, Maria Elena; Tenerani, Anna +1 more

A double adiabatically expanding solar wind would quickly develop large parallel to perpendicular temperature anisotropies in electrons and ions that are not observed. One reason is that firehose instabilities would be triggered, leading to an ongoing driving/saturation evolution mechanism. We verify this assumption here for the first time for the…

2019 The Astrophysical Journal
Cluster 13
Kinetic Monte Carlo Model for the Precipitation of High-Energy Protons and Hydrogen Atoms into the Atmosphere of Mars with Taking into Account the Measured Magnetic Field
DOI: 10.1134/S1063772919100056 Bibcode: 2019ARep...63..835S

Gérard, J. -C.; Hubert, B.; Shematovich, V. I. +1 more

Results of model computations of the interaction of the high-energy protons and hydrogen atoms (H/H+) precipitating into the Martian atmosphere are presented. These computations were performed using a modification of the kinetic Monte Carlo model developed earlier for the analysis of the data from the MEX/ASPERA-3 instrument onboard the…

2019 Astronomy Reports
MEx 13
An equatorial thermal wind equation: Applications to Jupiter
DOI: 10.1016/j.icarus.2018.09.037 Bibcode: 2019Icar..324..198M

Wong, Michael H.; Tollefson, Joshua; Marcus, Philip S. +1 more

To relate the vertical wind shear to horizontal temperature gradients at and near the equator, we derive an "Equatorial Thermal Wind Equation" (EQTWE) using a minimum set of assumptions that are easily satisfied for the atmospheres of all the giant planets and Earth. Similar to the textbook Thermal Wind Equation (TWE), the EQTWE requires a small R…

2019 Icarus
eHST 13