Results 31 to 40 of about 904 (176)

Investigating stellar surface rotation using observations of starspots [PDF]

, 2011
Rapid rotation enhances the dynamo operating in stars, and thus also introduces significantly stronger magnetic activity than is seen in slower rotators.
Korhonen, Heidi Helena
core   +1 more source

Asteroseismic Signature of a Large Active Region

Frontiers in Astronomy and Space Sciences, 2019
Axisymmetric magnetic activity on the Sun and sun-like stars increases the frequencies of the modes of acoustic oscillation. However, it is unclear how a corotating patch of activity affects the oscillations, since such a perturbation is unsteady in the ...
Emanuele Papini, Laurent Gizon, Laurent Gizon   +2 more
doaj   +1 more source

Overfitting Affects the Reliability of Radial Velocity Mass Estimates of the V1298 Tau Planets

The Astronomical Journal, 2023
Mass, radius, and age measurements of young (≲100 Myr) planets have the power to shape our understanding of planet formation. However, young stars tend to be extremely variable in both photometry and radial velocity (RV) measurements, which makes ...
Sarah Blunt, Adolfo Carvalho, Trevor J. David, Charles Beichman, Jon K. Zink, Eric Gaidos, Aida Behmard, Luke G. Bouma, Devin Cody, Fei Dai, Daniel Foreman-Mackey, Sam Grunblatt, Andrew W. Howard, Molly Kosiarek, Heather A. Knutson, Ryan A. Rubenzahl, Corey Beard, Ashley Chontos, Steven Giacalone, Teruyuki Hirano, Marshall C. Johnson, Jack Lubin, Joseph M. Akana Murphy, Erik A Petigura, Judah Van Zandt, Lauren Weiss   +25 more
doaj   +1 more source

High Tide or Riptide on the Cosmic Shoreline? A Water-rich Atmosphere or Stellar Contamination for the Warm Super-Earth GJ 486b from JWST Observations

The Astrophysical Journal Letters, 2023
Planets orbiting M-dwarf stars are prime targets in the search for rocky exoplanet atmospheres. The small size of M dwarfs renders their planets exceptional targets for transmission spectroscopy, facilitating atmospheric characterization.
Sarah E. Moran, Kevin B. Stevenson, David K. Sing, Ryan J. MacDonald, James Kirk, Jacob Lustig-Yaeger, Sarah Peacock, L. C. Mayorga, Katherine A. Bennett, Mercedes López-Morales, E. M. May, Zafar Rustamkulov, Jeff A. Valenti, Jéa I. Adams Redai, Munazza K. Alam, Natasha E. Batalha, Guangwei Fu, Junellie Gonzalez-Quiles, Alicia N. Highland, Ethan Kruse, Joshua D. Lothringer, Kevin N. Ortiz Ceballos, Kristin S. Sotzen, Hannah R. Wakeford   +23 more
doaj   +1 more source

Starspots on by DRA-Type Stars [PDF]

Highlights of Astronomy, 1977
The first detection of spots on dwarf M stars was by Kron on YY Geminorum in 1948. Since then phenomena attributable to starspots have been found by numerous authors beginning with Kraft and Krzeminski on the star now known as BY Draconis and on CC Eridani by Evans.
openaire   +1 more source

Modeling starspots on low mass star GJ 1243 observed by TESS

, 2021
Quasi-periodic modulations of the stellar light curve may result from dark spots crossing the visible stellar disc. Since the release of the first TESS sector the possibility of examining such quasi-periodic modulations by assumed dark spots has ...
Falewicz, Robert, Pietras, Małgorzata, Bicz, Kamil   +2 more
core   +1 more source

Interferometric Images of the Starspot Evolution of ζ Andromedae

The Astrophysical Journal
The evolution of starspots of the giant primaries of RS CVn systems is typically detected indirectly with photometric and spectroscopic monitoring. These observations suggest slowly-evolving stellar surfaces and can constrain differential rotation as ...
Rachael M. Roettenbacher, John D. Monnier, Heidi Korhonen, Gregory W. Henry, Cliff Kotnik, Joshua Pepper, Bálint Seli, Krisztián Vida, Attila Bódi, Borbála Cseh, Géza Csörnyei, Máté Krezinger, Réka Könyves-Tóth, Levente Kriskovics, Krisztián Sárneczky, Ádám Sódor, Róbert Szakáts, Stefan Kraus, Narsireddy Anugu, Claire L. Davies, Tyler Gardner, Cyprien Lanthermann, Gail H. Schaefer, Benjamin R. Setterholm   +23 more
doaj   +1 more source

Measuring the Temperature of Starspots from Multi-filter Photometry

The Astronomical Journal, 2023
Using simultaneous multi-filter observations during the transit of an exoplanet around a K dwarf star, we determine the temperature of a starspot through modeling the radius and position with wavelength-dependent spot contrasts.
Maria C. Schutte, Leslie Hebb, John P. Wisniewski, Caleb I. Cañas, Jessica E. Libby-Roberts, Andrea S. J. Lin, Paul Robertson, Gumundur Stefánsson   +7 more
doaj   +1 more source

Surface image and activity-corrected orbit of the RSCVn binary HR7275

Astronomy & Astrophysics
Context. Quantifying stellar parameters and magnetic activity for cool stars in double-lined spectroscopic binaries (SB2s) is not straightforward, as both stars contribute to the observed composite spectra and are likely variable.
Adebali Ö., Weber M., Strassmeier K. G., Ilyin I. V., Steffen M., Kővári Zs.   +5 more
doaj   +1 more source

Starspots as an Explanation for the Mysterious IYJ Continuum Excess Emission in Classical T Tauri Stars

The Astrophysical Journal
An accurate estimation of the continuum excess emission from accretion spots and inner circumstellar disk regions is crucial for a proper derivation of fundamental stellar parameters in accreting systems.
Facundo Pérez Paolino, Jeffrey S. Bary, Lynne A. Hillenbrand, Madison Markham, William J. Fischer   +4 more
doaj   +1 more source