Results 41 to 50 of about 1,347 (178)

Joint Modeling of Radial Velocities and Photometry with a Gaussian Process Framework

The Astrophysical Journal, 2023
Developments in the stability of modern spectrographs have led to extremely precise instrumental radial velocity (RV) measurements. For most stars, the detection limit of planetary companions with these instruments is expected to be dominated by ...
Quang H. Tran, Megan Bedell, Daniel Foreman-Mackey, Rodrigo Luger   +3 more
doaj   +1 more source

Contemporaneous Observations of Hα Luminosities and Photometric Amplitudes for M Dwarfs

The Astronomical Journal, 2023
While many M dwarfs are known to have strong magnetic fields and high levels of magnetic activity, we are still unsure about the properties of their starspots and the origin of their magnetic dynamos.
Aylin García Soto, Elisabeth R. Newton, Stephanie T. Douglas, Abigail Burrows, Aurora Y. Kesseli   +4 more
doaj   +1 more source

Interferometric Imaging of λ Andromedae: Evidence of Starspots and Rotation [PDF]

, 2021
Presented are the first interferometric images of cool starspots on the chromospherically active giant λ Andromedae. Using the Michigan Infra-Red Combiner coupled to the Center for High Angular Resolution Astronomy Array, 26 interferometric observations ...
White, Russel J., Sturmann, Laszlo, Monnier, John D., Zhao, Ming, Parks, J. Robert, Turner, Nils, Che, Xiao, Sturmann, Judit, ten Brummelaar, Theo, Baron, Frédérique, Schaefer, Gail, McAlister, Harold, Kloppenborg, Brian, Henry, Gregory W., Thureau, Nathalie, Ridgway, Stephen T., Pedretti, Ettore   +16 more
core   +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

Starspots on late-type stars and their correlation with flare activity

, 2018
 Recent space-based observations (e.g., Kepler mission) found thousands of ``superflares’’ on G-, K-, and M-type stars. These superflare stars show quasi-periodic brightness variations caused by the rotation of the star with starspots.
Honda, Satoshi (5266576), Namekata, Kousuke, Nogami, Daisaku, Namekata, Kousuke (5981468), Honda, Satoshi, Ikuta, Kai (5981471), Maehara, Hiroyuki (5266573), Shibata, Kazunari, Notsu, Shota (5266570), Notsu, Shota, Ikuta, Kai, Notsu, Yuta (5266585), Notsu, Yuta, Shibata, Kazunari (5266579), Maehara, Hiroyuki, Nogami, Daisaku (5266582)   +15 more
core   +1 more source

A New Approach to the Long-Term Activity Behavior of DM UMa

Open Astronomy, 2012
A long-term activity character of DM UMa (K0-1 IV-III), which is one of the most active members of the RS CVn type variables, is examined using the multicolor photometric observations which spread to the time interval between 1980 and 2009. In this work,
Taş G., Evren S.
doaj   +1 more source

Geodynamics of Super‐Earth GJ 486b

Journal of Geophysical Research: Planets, Volume 129, Issue 10, October 2024.
Abstract Many super‐Earths are on very short orbits around their host star and, therefore, more likely to be tidally locked. Because this locking can lead to a strong contrast between the dayside and nightside surface temperatures, these super‐Earths could exhibit mantle convection patterns and tectonics that could differ significantly from those ...
Tobias G. Meier, Dan J. Bower, Tim Lichtenberg, Mark Hammond, Paul J. Tackley, Raymond T. Pierrehumbert, José A. Caballero, Shang‐Min Tsai, Megan Weiner Mansfield, Nicola Tosi, Philipp Baumeister   +10 more
wiley   +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

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