Article
Astronomy & Astrophysics
J. A. Caballero, E. Gonzalez-Alvarez, M. Brady, T. Trifonov, T. G. Ellis, C. Dorn, C. Cifuentes, K. Molaverdikhani, J. L. Bean, T. Boyajian, E. Rodriguez, J. Sanz-Forcada, M. R. Zapatero Osorio, C. Abia, P. J. Amado, N. Anugu, V. J. S. Bejar, C. L. Davies, S. Dreizler, F. Dubois, J. Ennis, N. Espinoza, C. D. Farrington, A. Garcia Lopez, T. Gardner, A. P. Hatzes, Th Henning, E. Herrero, E. Herrero-Cisneros, A. Kaminski, D. Kasper, R. Klement, S. Kraus, A. Labdon, C. Lanthermann, J-B Le Bouquin, M. J. Lopez Gonzalez, R. Luque, A. W. Mann, E. Marfil, J. D. Monnier, D. Montes, J. C. Morales, E. Palle, S. Pedraz, A. Quirrenbach, S. Reffert, A. Reiners, I Ribas, C. Rodriguez-Lopez, G. Schaefer, A. Schweitzer, A. Seifahrt, B. R. Setterholm, Y. Shan, D. Shulyak, E. Solano, K. R. Sreenivas, G. Stefansson, J. Stuermer, H. M. Tabernero, L. Tal-Or, T. ten Brummelaar, S. Vanaverbeke, K. von Braun, A. Youngblood, M. Zechmeister
Summary: This study thoroughly characterizes the Gl 486 planetary system using new and precise data collected from space and ground-based instruments. The results provide insights into the internal structure and composition of the planet, which can be further studied in atmospheric research.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
B. A. Nicholson, G. Hussain, J-F Donati, D. Wright, C. P. Folsom, R. Wittenmyer, J. Okumura, B. D. Carter
Summary: In this study, spectropolarimetric observations of low-mass weak-line T Tauri stars TWA 25 and TWA 7 were analyzed, which revealed predominantly toroidal and non-axisymmetric surface magnetic fields for both stars. Surface brightness distributions were reconstructed to filter out activity-induced radial velocity variations, ruling out the presence of close-in giant planets for both stars. Longitudinal magnetic field measurements were shown to be useful in identifying activity-induced radial velocity variations.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
E. L. Brown, S. C. Marsden, M. W. Mengel, S. Jeffers, I Millburn, M. Mittag, P. Petit, A. A. Vidotto, J. Morin, V See, M. Jardine, J. N. Gonzalez-Perez
Summary: Studying cool star magnetic activity provides insights into the stellar dynamo and its connection with stellar properties, helping us understand the Sun's magnetism in relation to other stars. Research on HD75332 suggests the presence of a rapid solar-like magnetic cycle, possibly linked to its formation mechanisms.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
C. Pezzotti, G. Ottoni, G. Buldgen, A. Lyttle, P. Eggenberger, S. Udry, D. Segransan, M. Mayor, C. Lovis, M. Marmier, A. Miglio, Y. Elsworth, G. R. Davies, W. H. Ball
Summary: This study presents a comprehensive investigation of HD 29399 and its companion, including radial-velocity measurements, seismic characterization of the host star, and modeling of the orbital evolution of the system. The detection of a long-period giant planet is reported, and thorough modeling of the host star and study of the system's orbital evolution are achieved. Results include the determination of stellar and planetary masses, as well as the age of the system, and it is shown that neither dynamical nor equilibrium tides affect the orbital evolution of the planet.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
E. L. Brown, S. C. Marsden, M. W. Mengel, S. Jeffers, I Millburn, M. Mittag, P. Petit, A. A. Vidotto, J. Morin, V See, M. Jardine, J. N. Gonzalez-Perez
Summary: Studying the magnetic activity of cool stars like HD 75332 reveals similarities to the Sun's magnetic cycle, suggesting a possible synchronization with chromospheric activity and a connection to shallow convection zones, similar to the rapid magnetic cycles observed in tau Boo.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
M. Damasso, M. Perger, J. M. Almenara, D. Nardiello, M. Perez-Torres, A. Sozzetti, N. C. Hara, A. Quirrenbach, X. Bonfils, M. R. Zapatero Osorio, N. Astudillo-Defru, J. Gonzalez Hernandez, A. Suarez Mascareno, P. J. Amado, T. Forveille, J. Lillo-Box, Y. Alibert, J. A. Caballero, C. Cifuentes, X. Delfosse, P. Figueira, D. Galadi-Enriquez, A. P. Hatzes, Th Henning, A. Kaminski, M. Mayor, F. Murgas, D. Montes, M. Pinamonti, A. Reiners, I Ribas, V. J. S. Bejar, A. Schweitzer, M. Zechmeister
Summary: Based on the analysis of radial velocities and photometric data, a super-Earth planet on a likely eccentric orbit is discovered around Gl 514, which resides in the conservative habitable zone for nearly 34% of its orbital period. There may also be a second low-mass companion.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
K. Al Moulla, X. Dumusque, M. Cretignier, Y. Zhao, J. A. Valenti
Summary: This study investigates the dependence of derived radial velocities (RVs) on the formation temperature of spectral line segments. The results show that the activity-induced RV signal has different characteristics depending on the temperature range considered, with convective motion suppression being the dominant effect.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
L. Kriskovics, Zs. Kovari, B. Seli, K. Olah, K. Vida, G. W. Henry, T. Granzer, A. Goergei
Summary: Using more than 40 years of photometric time series, we analyze the long-term behavior of EI Eri. We investigate flare activity using data obtained from TESS. By conducting a multi-site observing campaign, we reconstruct successive surface-temperature maps of the star and study the changes of starspots on a very short timescale.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Szanna Zsiros, Andrea P. Nagy, Tamas Szalai
Summary: We conducted an extensive analysis of the late-time mid-IR evolution of Type IIb SN 1993J, revealing a late-time mid-IR excess that can be described by the presence of two-component local dust. The source of these components could be either newly formed dust grains or heating of pre-existing dust via ongoing circumstellar matter interaction.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Manfred Cuntz, Klaus-Peter Schroder, Diaa E. Fawzy, Andrew R. Ridden-Harper
Summary: This study examines chromospheric heating models for 55 Cancri in conjunction with observations, focusing on acoustic waves and longitudinal flux tube waves. It is found that considering low levels of magnetic heating can lead to better agreement between theoretical models and observations.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
M. Flores, M. Jaque Arancibia, R. V. Ibanez Bustos, A. P. Buccino, J. Yana Galarza, N. E. Nunez, P. Miquelarena, J. Alacoria, C. Saffe, P. J. D. Mauas
Summary: Researchers studied the activity levels of stars in a binary system and found that zeta(1) Ret has high activity while zeta(2) Ret has a significantly decreased magnetic activity cycle amplitude, suggesting it may be in a state similar to the Maunder minimum. They also discovered a long-term activity cycle in zeta(1) Ret that was previously unreported.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Baptiste Klein, Jean-Francois Donati, Elodie M. Hebrard, Bonnie Zaire, Colin P. Folsom, Julien Morin, Xavier Delfosse, Xavier Bonfils
Summary: We report the detection of a large-scale magnetic field on the surface of the slowly rotating fully convective M dwarf Proxima Centauri using Zeeman-Doppler Imaging. The magnetic field on Proxima Centauri is mainly poloidal with a dipole component tilted at 51 degrees to the rotation axis. The large-scale magnetic flux is estimated to be roughly 3 times smaller than the flux measured from Zeeman broadening of unpolarized lines, indicating efficient dynamo generation of magnetic field at largest spatial scales.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Ekrem M. Esmer, Ozgur Basturk, Tobias C. Hinse, Selim O. Selam, Alexandre C. M. Correia
Summary: The study aims to analyze eclipse timing variations in the HW Vir system to determine the properties of circumbinary planets. By using robust model selection methods and error calculation techniques, the study found the masses of the binary system and the potential circumbinary objects' parameters, showing unstable orbital configurations for the outer circumbinary object.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Diaa E. Fawzy, Manfred Cuntz
Summary: We present theoretical models of chromospheric heating for 55 Cancri, focusing on the impact of longitudinal waves and acoustic waves on the Caii K fluxes. Our study explores the influence of magnetic heating on the stellar atmospheric structure and the emergent Caii emission, as well as the effects of non-linearities, showing that a higher photospheric magnetic filling factor leads to a larger Caii emission. Comparisons with observations will be discussed in forthcoming Paper II.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Justyn Campbell-White, Aurora Sicilia-Aguilar, Carlo F. Manara, Soko Matsumura, Min Fang, Antonio Frasca, Veronica Roccatagliata
Summary: The STAR-MELT PYTHON package facilitates the analysis of time-resolved emission-line spectroscopy of young stellar objects by automatically extracting, identifying, and fitting emission lines. Utilizing high-resolution stellar spectra in the time domain, it allows for the investigation of variability in line profiles and emitting regions. Results from applying STAR-MELT to various YSOs demonstrate the tool's effectiveness in analyzing disparate data sets.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)