Search Publications

Warm protons at comet 67P/Churyumov-Gerasimenko - implications for the infant bow shock
DOI: 10.5194/angeo-39-379-2021 Bibcode: 2021AnGeo..39..379G

Nilsson, Hans; Goetz, Charlotte; Gunell, Herbert +4 more

The plasma around comet 67P/Churyumov-Gerasimenko showed remarkable variability throughout the entire Rosetta mission. Plasma boundaries such as the diamagnetic cavity, solar wind ion cavity and infant bow shock separate regions with distinct plasma parameters from each other. Here, we focus on a particular feature in the plasma: warm, slow solar …

2021 Annales Geophysicae
Rosetta 12
Microwave diagnostics of magnetic field strengths in solar flaring loops
DOI: 10.1007/s11431-020-1620-7 Bibcode: 2021ScChE..64..169Z

Tian, Hui; Zhu, Rui; Xu, Yu +5 more

We have performed microwave diagnostics of the magnetic field strengths in solar flare loops based on the theory of gyrosynchrotron emission. From Nobeyama Radioheliograph observations of three flare events at 17 and 34 GHz, we obtained the degree of circular polarization and the spectral index of microwave flux density, which were then used to ma…

2021 Science in China E: Technological Sciences
SOHO 12
The Hubble PanCET program: long-term chromospheric evolution and flaring activity of the M dwarf host GJ 3470
DOI: 10.1051/0004-6361/202140487 Bibcode: 2021A&A...650A..73B

Sanz-Forcada, J.; Ehrenreich, D.; Bourrier, V. +9 more

Neptune-size exoplanets seem particularly sensitive to atmospheric evaporation, making it essential to characterize the stellar high-energy radiation that drives this mechanism. This is particularly important with M dwarfs, which emit a large and variable fraction of their luminosity in the ultraviolet and can display strong flaring behavior. The …

2021 Astronomy and Astrophysics
XMM-Newton eHST 12
SuperWASP variable stars: classifying light curves using citizen science
DOI: 10.1093/mnras/stab140 Bibcode: 2021MNRAS.502.1299T

Thiemann, Heidi B.; Norton, Andrew J.; Kolb, Ulrich C. +2 more

We present the first analysis of results from the SuperWASP variable stars Zooniverse project, which is aiming to classify 1.6 million phase-folded light curves of candidate stellar variables observed by the SuperWASP all sky survey with periods detected in the SuperWASP periodicity catalogue. The resultant data set currently contains >1 millio…

2021 Monthly Notices of the Royal Astronomical Society
Gaia 12
Another Superdense Sub-Neptune in K2-182 b and Refined Mass Measurements for K2-199 b and c
DOI: 10.3847/1538-3881/ac2830 Bibcode: 2021AJ....162..294A

Batalha, Natalie M.; Rosenthal, Lee J.; Hirsch, Lea A. +10 more

We combine multiple campaigns of K2 photometry with precision radial velocity measurements from Keck-HIRES to measure the masses of three sub-Neptune-sized planets. We confirm the planetary nature of the massive sub-Neptune K2-182 b (P b = 4.7 days, R b = 2.69 R ) and derive refined parameters for K2-199 b and c (…

2021 The Astronomical Journal
Gaia 12
Frequencies, chaos, and resonances: A study of orbital parameters of nearby thick-disc and halo stars
DOI: 10.1051/0004-6361/202039390 Bibcode: 2021A&A...647A..37K

Helmi, Amina; Koppelman, Helmer H.; Hagen, Jorrit H. J.


Aims: We study the distribution of nearby thick-disc and halo stars in subspaces defined by their characteristic orbital parameters. Our aim is to establish the origin of the structure reported in particular in the Rmax - zmax space.
Methods: To this end, we computed the orbital parameters and frequencies of stars f…

2021 Astronomy and Astrophysics
Gaia 12
The Extinction and Distance of the MBM Molecular Clouds at High Galactic Latitude
DOI: 10.3847/1538-4365/ac1601 Bibcode: 2021ApJS..256...46S

Ren, Yi; Jiang, Biwei; Zhao, He +1 more

Based on the accurate color excess {E}_{{{\rm{G}}}_{\mathrm{BP}},{{\rm{G}}}_{\mathrm{RP}}}$ of more than 4 million stars and the {E}_{\mathrm{NUV},{{\rm{G}}}_{\mathrm{BP}}}$ of more than 1 million stars from Sun et al., the distance and extinction of the molecular clouds (MCs) in the Magnani-Blitz-Mundy catalog at ∣b∣ > 20° are studied in combi…

2021 The Astrophysical Journal Supplement Series
Gaia 12
Extended envelopes around Galactic Cepheids. V. Multi-wavelength and time-dependent analysis of IR excess
DOI: 10.1051/0004-6361/202140350 Bibcode: 2021A&A...651A.113G

Kervella, P.; Mérand, A.; Lagadec, E. +6 more


Aims: We aim to investigate the infrared excess of 45 Milky Way (MW) Cepheids combining different observables in order to constrain the presence of circumstellar envelopes (CSEs).
Methods: We used the SpectroPhoto-Interferometry of Pulsating Stars (SPIPS) algorithm, a robust implementation of the parallax-of-pulsation method that combine…

2021 Astronomy and Astrophysics
AKARI Gaia 12
Gamma-ray and Neutrino Signals from Accretion Disk Coronae of Active Galactic Nuclei
DOI: 10.3390/galaxies9020036 Bibcode: 2021Galax...9...36I

Inoue, Yoshiyuki; Doi, Akihiro; Khangulyan, Dmitry

To explain the X-ray spectra of active galactic nuclei (AGN), non-thermal activity in AGN coronae such as pair cascade models has been extensively discussed in the past literature. Although X-ray and gamma-ray observations in the 1990s disfavored such pair cascade models, recent millimeter-wave observations of nearby Seyferts have established the …

2021 Galaxies
INTEGRAL 12
The K2 M67 Study: Precise Mass for a Turnoff Star in the Old Open Cluster M67
DOI: 10.3847/1538-3881/abca8d Bibcode: 2021AJ....161...59S

Vanderburg, Andrew; Latham, David W.; Stello, Dennis +8 more

We present a study of the bright detached eclipsing main-sequence binary WOCS 11028 (Sanders 617) in the open cluster M67. Although the binary has only one eclipse per orbital cycle, we show that the masses of the stars can be derived very precisely thanks to a strong constraint on the orbital inclination: MA = 1.222 ± 0.006M

2021 The Astronomical Journal
Gaia 12