Results 111 to 120 of about 1,347 (178)

Multiwavelength Campaign Observations of a Young Solar-type Star, EK Draconis. III. Comparison between Starspot Mapping, Zeeman Doppler Imaging, and Multiwavelength Variability

The Astrophysical Journal
Recent simultaneous multiwavelength observations of a nearby young solar-type star EK Draconis (EK Dra) in the optical, H α spectrum, and X-ray, have provided evidence for stellar prominence eruptions associated with superflares.
Kai Ikuta, Kosuke Namekata, Pascal Petit, Vladimir S. Airapetian, Hiroyuki Maehara, Yuta Notsu, Aline A. Vidotto, Keith Gendreau, Sandra V. Jeffers, Stephen Marsden, Julien Morin, Coralie Neiner, Rishi R. Paudel, Daisaku Nogami, Kazunari Shibata   +14 more
doaj   +1 more source

Starspot trek: The motion picture [PDF]

Contributions of the Astronomical Observatory Skalnaté Pleso, 2020
openaire   +1 more source

Quantifying the Transit Light Source Effect: Measurements of Spot Temperature and Coverage on the Photosphere of AU Microscopii with High-resolution Spectroscopy and Multicolor Photometry

The Astrophysical Journal
AU Microscopii (AU Mic) is an active 24 ± 3 Myr pre-main-sequence M dwarf in the stellar neighborhood ( d = 9.7 pc) with a rotation period of 4.86 days. The two transiting planets orbiting AU Mic, AU Mic b and c, are warm sub-Neptunes on 8.5 and 18.9 day
William C. Waalkes, Zachory K. Berta-Thompson, Elisabeth R. Newton, Andrew W. Mann, Peter Gao, Hannah R. Wakeford, Lili Alderson, Peter Plavchan   +7 more
doaj   +1 more source

Mitigating stellar activity in radial velocity measurements through the spectral tracking of starspots [PDF]

Context. Extreme-precision radial velocity observations used to search for low-mass extrasolar planets are hampered by astrophysical noise originating from stellar photospheres.
Dorval, P., Snellen, I.A.G., P. Dorval, I. Snellen, Snellen, I.,, Snellen, I., Dorval, Patrick, Dorval, Patrick,   +7 more
core   +1 more source

JWST MEP—A World Under Spotty Starlight: Detection of CO2 and H2O in the Hot Saturn WASP-52b with JWST NIRSpec G395H

The Astronomical Journal
Exoplanets orbiting active stars offer distinct challenges for atmospheric characterization with the JWST. Among such worlds, the hot Saturn WASP-52b ( T _eq  ∼ 1300 K) orbits an active K-dwarf that complicates transmission spectroscopy via stellar ...
Yanbo Pan, Ryan J. MacDonald, Néstor Espinoza, Bibiana Prinoth, Zafar Rustamkulov, Luis Welbanks, Daniel Kitzmann, Nicolas Crouzet, Anna Walde, Diana Powell, Eva-Maria Ahrer, Adam J. Burgasser, Duncan A. Christie, Wolf Cukier, Carlos Gascón, Måns Holmberg, Thomas Kennedy, Mercedes López-Morales, N. J. Mayne, Dominic Samra, Arjun B. Savel, Maria E. Steinrueck, Christopher P. Wirth, JWST GO 3969 Team   +23 more
doaj   +1 more source

Starspots and Flares are Generally Not Correlated

Sunspots and solar flares are two different manifestations of magnetic activity on the surface of the Sun. On the Sun, flares typically occur close to spots. In this paper we test this the connection between spots and flares on other stars. We detect 218,386 stellar flares on 14,163 spotted stars using a new algorithm called \textsc{toffee ...
Zhang, Andy B., Reeves, Jason R., Martin, David V., Pratt, Veronica, Tubthong, Wata, Weinstein, Arielle, Ward, Isabella E.   +6 more
openaire   +2 more sources

BS Cassiopeiae: A Contact Binary with Starspot-driven Variability and Evidence for Additional Components

The Astronomical Journal
We present a comprehensive photometric and spectroscopic analysis of the contact eclipsing binary BS Cas, based on 22 yr multisite light curves and 2 yr high-resolution spectra.
Min-Ji Jeong, Chun-Hwey Kim, Kyeongsoo Hong, Mi-Hwa Song, Hye-Young Kim, Jang-Ho Park, Cheongho Han, Joh-Na Yoon   +7 more
doaj   +1 more source

Starspots Found on the Ellipsoidal Variable V350 Lacertae = HR 8575 [PDF]

, 1995
It has been a puzzle why this chromospherically active, strong-dynamo K2 IV-III star is not known to have the large starspots characteristic of other such stars. Published individual radial velocities, which had never been analyzed, are used to derive an
Crews, Lionel J., Lines, Richard D., Hall, Douglas S., Henry, Gregory W., Lines, Helen C., Fried, Robert E.   +5 more
core  

Coincidence between Rotational Modulations of Coronal and Photospheric Activities on the Saturated Star AB Dor

The Astronomical Journal
The magnetic connection among different layers is observed on the Sun and plays a key role in solar activity. It is also expected to be common on other active stars.
Fu-Kun Xu, Shenghong Gu
doaj   +1 more source

A study of pulsation & rotation in a sample of A-K type stars in the Kepler field. [PDF]

Astrophys Space Sci, 2018
Chowdhury S, Joshi S, Engelbrecht CA, De Cat P, Joshi YC, Paul KT.   +5 more
europepmc   +1 more source