scholarly journals ROSAT observations of V471 Tauri, showing that stellar activity is determined by rotation, not age

1998 ◽  
Vol 297 (4) ◽  
pp. 1145-1150 ◽  
Author(s):  
P. J. Wheatley
Keyword(s):  
Stellar Activity

Stellar Activity in Coeval Open Clusters: Praesepe and the Hyades

1998 ◽  
Vol 506 (1) ◽  
pp. 347-359 ◽  
Author(s):  
David Barrado y Navascués ◽  
John R. Stauffer ◽  
Sofia Randich
Keyword(s):  
Open Clusters ◽  
Stellar Activity

scholarly journals Stellar activity and magnetic shielding

2009 ◽  
Vol 5 (S264) ◽  
pp. 385-394 ◽  
Author(s):  
J.-M. Grießmeier ◽  
M. Khodachenko ◽  
H. Lammer ◽  
J. L. Grenfell ◽  
A. Stadelmann ◽  
...  
Keyword(s):  
Dipole Moment ◽  
Magnetic Dipole ◽  
Magnetic Dipole Moment ◽  
Direct Interaction ◽  
Planetary Atmosphere ◽  
Stellar Activity ◽  
Planetary Environment ◽  
Atmospheric Loss ◽  
Planetary Magnetic Field ◽  
Planetary Habitability

AbstractStellar activity has a particularly strong influence on planets at small orbital distances, such as close-in exoplanets. For such planets, we present two extreme cases of stellar variability, namely stellar coronal mass ejections and stellar wind, which both result in the planetary environment being variable on a timescale of billions of years. For both cases, direct interaction of the streaming plasma with the planetary atmosphere would entail servere consequences. In certain cases, however, the planetary atmosphere can be effectively shielded by a strong planetary magnetic field. The efficiency of this shielding is determined by the planetary magnetic dipole moment, which is difficult to constrain by either models or observations. We present different factors which influence the strength of the planetary magnetic dipole moment. Implications are discussed, including nonthermal atmospheric loss, atmospheric biomarkers, and planetary habitability.

scholarly journals Stellar activity, differential rotation, and exoplanets

2010 ◽  
Vol 6 (S273) ◽  
pp. 89-95 ◽  
Author(s):  
A. F. Lanza
Keyword(s):  
Time Series ◽  
Differential Rotation ◽  
Solar Irradiance ◽  
Giant Planet ◽  
Total Solar Irradiance ◽  
Short Term ◽  
Stellar Activity ◽  
Transiting Planets ◽  
Spot Model ◽  
Spot Activity

AbstractThe photospheric spot activity of some of the stars with transiting planets discovered by the CoRoT space experiment is reviewed. Their out-of-transit light modulations are fitted by a spot model previously tested with the total solar irradiance variations. This approach allows us to study the longitude distribution of the spotted area and its variations versus time during the five months of a typical CoRoT time series. The migration of the spots in longitude provides a lower limit for the surface differential rotation, while the variation of the total spotted area can be used to search for short-term cycles akin the solar Rieger cycles. The possible impact of a close-in giant planet on stellar activity is also discussed.

Origin of the Continuous Component of the Variation in the Solar and Stellar Activity Spectra

2021 ◽  
Vol 61 (7) ◽  
pp. 911-916
Author(s):  
D. D. Sokoloff ◽  
P. G. Frick
Keyword(s):  
Continuous Component ◽  
Stellar Activity

scholarly journals The stellar activity-rotation relationship revisited: Dependence of saturated and non-saturated X-ray emission regimes on stellar mass for late-type dwarfs

2002 ◽  
Vol 397 (1) ◽  
pp. 147-157 ◽  
Author(s):  
N. Pizzolato ◽  
A. Maggio ◽  
G. Micela ◽  
S. Sciortino ◽  
P. Ventura
Keyword(s):  
Stellar Mass ◽  
Late Type ◽  
Stellar Activity ◽  
X Ray

scholarly journals DISENTANGLING PLANETS AND STELLAR ACTIVITY FOR GLIESE 667C

2014 ◽  
Vol 793 (2) ◽  
pp. L24 ◽  
Author(s):  
Paul Robertson ◽  
Suvrath Mahadevan
Keyword(s):  
Stellar Activity

Inferences on Stellar Activity and Stellar Cycles from Asteroseismology

2015 ◽  
pp. 437-456 ◽  
Author(s):  
William J. Chaplin ◽  
Sarbani Basu
Keyword(s):  
Stellar Activity

scholarly journals Disentangling stellar activity from exoplanetary signals with interferometry

2015 ◽  
Vol 101 ◽  
pp. 05004
Author(s):  
Roxanne Ligi ◽  
Denis Mourard ◽  
Anne-Marie Lagrange ◽  
Karine Perraut ◽  
Andrea Chiavassa
Keyword(s):  
Stellar Activity

scholarly journals Solar and stellar activity cycles

2008 ◽  
Vol 118 ◽  
pp. 012032 ◽  
Author(s):  
Matthias Rempel
Keyword(s):  
Stellar Activity ◽  
Activity Cycles

scholarly journals Planets and Stellar Activity: Hide and Seek in the CoRoT-7 system

2013 ◽  
Vol 8 (S299) ◽  
pp. 237-240
Author(s):  
R. D. Haywood ◽  
A. C. Cameron ◽  
D. Queloz ◽  
S. C. C. Barros ◽  
M. Deleuil ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Markov Chain ◽  
Precise Determination ◽  
Photometric Data ◽  
Stellar Activity ◽  
Level Of Activity ◽  
Reliable Detection ◽  
Harmonic Decomposition ◽  
High Level

AbstractSince the discovery of the transiting Super-Earth CoRoT-7b, several investigations have been made of the number and precise masses of planets present in the system, but they all yield different results, owing to the star's high level of activity. Radial velocity (RV) variations induced by stellar activity therefore need to be modelled and removed to allow a reliable detection of all planets in the system. We re-observed CoRoT-7 in January 2012 with both HARPS and the CoRoT satellite, so that we now have the benefit of simultaneous RV and photometric data. We fitted the off-transit variations in the CoRoT lightcurve using a harmonic decomposition similar to that implemented in Queloz et al. (2009). This fit was then used to model the stellar RV contribution, according to the methods described by Aigrain et al. (2011). This model was incorporated into a Monte Carlo Markov Chain in order to make a precise determination of the orbits of CoRoT-7b and CoRoT-7c. We also assess the evidence for the presence of one or two additional planetary companions.

Sign in / Sign up

Export Citation Format

Share Document