English
Related papers

Related papers: Is the primary CoRoT target HD43587 under a Maunde…

200 papers

Solar inter-network magnetic field is the weakest component of solar magnetism, but contributes most of the solar surface magnetic flux. The study on its origin has been constrained by the inadequate tempo-spatial resolution and sensitivity…

Solar and Stellar Astrophysics · Physics 2015-05-26 Chunlan Jin , Jingxiu Wang

We present the combined results of three photometric monitoring campaigns targeting very low mass (VLM) stars and brown dwarfs in the young open cluster IC4665 (age ~40 Myr). In all three runs, we observe ~100 cluster members, allowing us…

Solar and Stellar Astrophysics · Physics 2015-05-14 Alexander Scholz , Jochen Eisloeffel , Reinhard Mundt

We present an investigation of three chemically peculiar (CP) stars and one CP star candidate which exhibit photometric periods below 12 hours. New spectroscopic observations have been acquired which confirm the peculiar nature of all…

Solar and Stellar Astrophysics · Physics 2017-01-25 Stefan Hümmerich , Klaus Bernhard , Ernst Paunzen , Franz-Josef Hambsch , Terry Bohlsen , Jonathan Powles

We performed two data-based magnetohydrodynamic (MHD) simulations for solar active region 12371 which produced an M6.5 flare. The first simulation is a full data-driven simulation where the initial condition is given by a nonlinear…

Solar and Stellar Astrophysics · Physics 2023-03-01 Satoshi Inoue , Keiji Hayashi , Takahiro Miyoshi , Ju Jing , Haimin Wang

Based on optical high-resolution spectra obtained with CFHT/ESPaDOnS, we present new measurements of activity and magnetic field proxies of 442 low-mass K5-M7 dwarfs. The objects were analysed as potential targets to search for…

Solar and Stellar Astrophysics · Physics 2017-09-07 C. Moutou , E. M. Hebrard , J. Morin , L. Malo , P. Fouque , A. Torres-Rivas , E. Martioli , X. Delfosse , E. Artigau , R. Doyon

In November 2021, Solar Orbiter started its nominal mission phase. The remote-sensing instruments on board the spacecraft acquired scientific data during three observing windows surrounding the perihelion of the first orbit of this phase.…

We report the results of the analysis of high resolution photospheric line spectra obtained with the UVES instrument on the VLT for a sample of 15 solar-type stars selected from a recent survey of the distribution of H and K chromospheric…

Solar and Stellar Astrophysics · Physics 2014-11-20 Ansgar Reiners , Mark S. Giampapa

The Maunder Minimum (1645-1715 approximately) was a period of very low solar activity and a strong hemispheric asymmetry, with most of sunspots in the southern hemisphere. In this paper, two data sets of sunspot latitudes during the Maunder…

Solar and Stellar Astrophysics · Physics 2015-01-27 J. M. Vaquero , J. M. Nogales , F. Sánchez-Bajo

We present the analysis of the time series observations of CoRoT\,102699796 obtained by the CoRoT satellite that show the presence of five independent oscillation frequencies in the range 3.6-5 c/d. Using spectra acquired with FLAMES@VLT,…

Solar and Stellar Astrophysics · Physics 2015-05-28 V. Ripepi , F. Cusano , M. Di Criscienzo , G. Catanzaro , F. Palla , M. Marconi , P. Ventura , C. Neiner , C. Catala , S. Bernabei

In this paper, we simulate the magnetic flux evolution at different heliocentric distances during two solar-maximum Carrington rotations (CRs) using the time-evolving coronal magnetohydrodynamic (MHD) model COCONUT to investigate the ``open…

Stellar rotation periods measured in open clusters have proved to be extremely useful for studying stars' angular momentum content and rotationally driven magnetic activity, which are both age- and mass-dependent processes. While period…

Solar and Stellar Astrophysics · Physics 2016-05-25 Kevin R. Covey , Marcel A. Agüeros , Nicholas M. Law , Jiyu Liu , Aida Ahmadi , Russ Laher , David Levitan , Branimir Sesar , Jason Surace

We study a sample of 21 young and active solar-type stars with spectral types ranging from late F to mid K and characterize the behaviour of their activity. We apply the continuous period search (CPS) time series analysis method on 16 to 27…

Solar and Stellar Astrophysics · Physics 2016-03-21 Jyri Lehtinen , Lauri Jetsu , Thomas Hackman , Perttu Kajatkari , Gregory W. Henry

The high performance photometric data obtained with space mission CoRoT offer the opportunity to efficiently constrain our models for the stellar interior of solar-like pulsating stars. On the occasion of the analysis of the oscillations of…

Solar and Stellar Astrophysics · Physics 2011-03-28 S. Deheuvels , E. Michel

Surface differential rotation (SDR) plays a key role in dynamo models. SDR estimates are therefore essential for constraining theoretical models. We measure a lower limit to SDR in a sample of solar-like stars belonging to young…

Solar and Stellar Astrophysics · Physics 2016-06-15 E. Distefano , A. C. Lanzafame , A. F. Lanza , S. Messina , F. Spada

We present a magnetic activity study of GJ 436 using spectroscopic data from HARPS, spanning over 14 years, and additional data from NARVAL, falling within the HARPS observations. We study the CaII H&K, HeID3, NaI doublet, H$\alpha$ and…

Solar and Stellar Astrophysics · Physics 2022-10-26 M. Kumar , R. Fares

Jupiter-family comet (JFC) P/2021 HS (PANSTARRS) only exhibits a coma within a few weeks of its perihelion passage at 0.8~au, which is atypical for a comet. Here we present an investigation into the underlying cause using serendipitous…

During the last decade, the relation between activity cycle periods with stellar parameters has received special attention. The construction of reliable registries of activity reveals that solar type stars exhibit activity cycles with…

Solar and Stellar Astrophysics · Physics 2020-08-26 A. P. Buccino , L. Sraibman , P. Olivar , F. Minotti

We study the relation between stellar rotation and magnetic activity for a sample of 134 bright, nearby M dwarfs observed in the Kepler Two-Wheel (K2) mission during campaigns C0 to C4. The K2 lightcurves yield photometrically derived…

Solar and Stellar Astrophysics · Physics 2016-08-17 B. Stelzer , M. Damasso , A. Scholz , S. P. Matt , --

The Mount Wilson Ca HK survey revealed magnetic activity variations in a large sample of solar-type stars with timescales ranging from 2.5 to 25 years. This broad range of cycle periods is thought to reflect differences in the rotational…

Solar and Stellar Astrophysics · Physics 2009-10-01 T. S. Metcalfe , P. G. Judge , S. Basu , T. J. Henry , D. R. Soderblom , M. Knoelker , M. Rempel

The differential rotation plays a crucial role in the dynamics of the Sun. We study the solar rotation and its correlation with solar activity by applying a modified machine learning algorithm to identify and track coronal bright points…

Solar and Stellar Astrophysics · Physics 2024-07-30 Zahra Shokri , Nasibe Alipour , Hossein Safari