Zobrazeno 1 - 10
of 105
pro vyhledávání: '"Steven H. Saar"'
Publikováno v:
The Astrophysical Journal, Vol 973, Iss 1, p 11 (2024)
Stellar photospheric inhomogeneities are a significant source of noise, which currently precludes the discovery of Earth-mass planets orbiting Sun-like stars with the radial-velocity (RV) method. To complement several previous studies that have used
Externí odkaz:
https://doaj.org/article/f97484c2c4da4162925788610275c132
Autor:
Travis S. Metcalfe, Derek Buzasi, Daniel Huber, Marc H. Pinsonneault, Jennifer L. van Saders, Thomas R. Ayres, Sarbani Basu, Jeremy J. Drake, Ricky Egeland, Oleg Kochukhov, Pascal Petit, Steven H. Saar, Victor See, Keivan G. Stassun, Yaguang Li, Timothy R. Bedding, Sylvain N. Breton, Adam J. Finley, Rafael A. García, Hans Kjeldsen, Martin B. Nielsen, J. M. Joel Ong, Jakob L. Rørsted, Amalie Stokholm, Mark L. Winther, Catherine A. Clark, Diego Godoy-Rivera, Ilya V. Ilyin, Klaus G. Strassmeier, Sandra V. Jeffers, Stephen C. Marsden, Aline A. Vidotto, Sallie Baliunas, Willie Soon
Publikováno v:
The Astronomical Journal, Vol 166, Iss 4, p 167 (2023)
The bright star λ Ser hosts a hot Neptune with a minimum mass of 13.6 M _⊕ and a 15.5 day orbit. It also appears to be a solar analog, with a mean rotation period of 25.8 days and surface differential rotation very similar to the Sun. We aim to ch
Externí odkaz:
https://doaj.org/article/cb097db1977143629195bc3f6d94b093
Publikováno v:
The Astrophysical Journal, Vol 951, Iss 2, p 152 (2023)
We carry out detailed spectral and timing analyses of the Chandra X-ray data of HD 179949, a prototypical example of a star with a close-in giant planet with possible star–planet interaction (SPI) effects. We find a low coronal abundance A (Fe)/ A
Externí odkaz:
https://doaj.org/article/782a5254198d40a5bbd46c296f5df303
Publikováno v:
The Astrophysical Journal, Vol 949, Iss 2, p 51 (2023)
An α Ω dynamo, combining shear and cyclonic convection in the tachocline, is believed to generate the solar cycle. However, this model cannot explain cycles in fast rotators (with minimal shear) or in fully convective stars (no tachocline); an anal
Externí odkaz:
https://doaj.org/article/4639621852b94ca2b6b59a82229a5898
HD 166620 was recently identified as a Maunder Minimum candidate based on nearly 50 years of Ca II H & K activity data from Mount Wilson and Keck-HIRES (Baum et al. 2022). These data showed clear cyclic behavior on a 17-year timescale during the Moun
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::5f0b84938c1565f79f7ce8a4b958ec2f
http://arxiv.org/abs/2207.00612
http://arxiv.org/abs/2207.00612
Autor:
Chantanelle Nava, Mercedes López-Morales, Annelies Mortier, Li Zeng, Helen A. C. Giles, Allyson Bieryla, Andrew Vanderburg, Lars A. Buchhave, Ennio Poretti, Steven H. Saar, Xavier Dumusque, David W. Latham, David Charbonneau, Mario Damasso, Aldo S. Bonomo, Christophe Lovis, Andrew Collier Cameron, Jason D. Eastman, Alessandro Sozzetti, Rosario Cosentino, Marco Pedani, Francesco Pepe, Emilio Molinari, Dimitar Sasselov, Michel Mayor, Manu Stalport, Luca Malavolta, Ken Rice, Christopher A. Watson, A. F. Martinez Fiorenzano, Luca Di Fabrizio
Publikováno v:
The Astronomical Journal
Nava, C, López-Morales, M, Mortier, A, Zeng, L, Giles, H A C, Bieryla, A, Vanderburg, A, Buchhave, L A, Poretti, E, Saar, S H, Dumusque, X, Latham, D W, Charbonneau, D, Damasso, M, Bonomo, A S, Lovis, C, Collier Cameron, A, Eastman, J D, Sozzetti, A, Cosentino, R, Pedani, M, Pepe, F, Molinari, E, Sasselov, D, Mayor, M, Stalport, M, Malavolta, L, Rice, K, Watson, C A, Martinez Fiorenzano, A F & Di Fabrizio, L 2022, ' K2-79b and K2-222b: Mass Measurements of Two Small Exoplanets with Periods beyond 10 days that Overlap with Periodic Magnetic Activity Signals ', Astronomical Journal, vol. 163, no. 2, 41 . https://doi.org/10.3847/1538-3881/ac3141
Nava, C, López-Morales, M, Mortier, A, Zeng, L, Giles, H A C, Bieryla, A, Vanderburg, A, Buchhave, L A, Poretti, E, Saar, S H, Dumusque, X, Latham, D W, Charbonneau, D, Damasso, M, Bonomo, A S, Lovis, C, Cameron, A C, Eastman, J D, Sozzetti, A, Cosentino, R, Pedani, M, Pepe, F, Molinari, E, Sasselov, D, Mayor, M, Stalport, M, Malavolta, L, Rice, K, Watson, C A, Fiorenzano, A F M & Fabrizio, L D 2022, ' K2-79b and K2-222b: Mass measurements of two small exoplanets with periods beyond 10 days that overlap with periodic magnetic activity signals ', Astronomical Journal, vol. 163, no. 2, 41, pp. 1-23 . https://doi.org/10.3847/1538-3881/ac3141
Nava, C, López-Morales, M, Mortier, A, Zeng, L, Giles, H A C, Bieryla, A, Vanderburg, A, Buchhave, L A, Poretti, E, Saar, S H, Dumusque, X, Latham, D W, Charbonneau, D, Damasso, M, Bonomo, A S, Lovis, C, Collier Cameron, A, Eastman, J D, Sozzetti, A, Cosentino, R, Pedani, M, Pepe, F, Molinari, E, Sasselov, D, Mayor, M, Stalport, M, Malavolta, L, Rice, K, Watson, C A, Martinez Fiorenzano, A F & Di Fabrizio, L 2022, ' K2-79b and K2-222b: Mass Measurements of Two Small Exoplanets with Periods beyond 10 days that Overlap with Periodic Magnetic Activity Signals ', Astronomical Journal, vol. 163, no. 2, 41 . https://doi.org/10.3847/1538-3881/ac3141
Nava, C, López-Morales, M, Mortier, A, Zeng, L, Giles, H A C, Bieryla, A, Vanderburg, A, Buchhave, L A, Poretti, E, Saar, S H, Dumusque, X, Latham, D W, Charbonneau, D, Damasso, M, Bonomo, A S, Lovis, C, Cameron, A C, Eastman, J D, Sozzetti, A, Cosentino, R, Pedani, M, Pepe, F, Molinari, E, Sasselov, D, Mayor, M, Stalport, M, Malavolta, L, Rice, K, Watson, C A, Fiorenzano, A F M & Fabrizio, L D 2022, ' K2-79b and K2-222b: Mass measurements of two small exoplanets with periods beyond 10 days that overlap with periodic magnetic activity signals ', Astronomical Journal, vol. 163, no. 2, 41, pp. 1-23 . https://doi.org/10.3847/1538-3881/ac3141
We present mass and radius measurements of K2-79b and K2-222b, two transiting exoplanets orbiting active G-type stars. Their respective 10.99d and 15.39d orbital periods fall near periods of signals induced by stellar magnetic activity. The two signa
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::fa3933bba179ec1d6d452237a5198a1a
Autor:
Willie Soon, Tiago L. Campante, Travis S. Metcalfe, Jeremy J. Drake, Oleg Kochukhov, Sallie L. Baliunas, Steven H. Saar, Adam J. Finley, Daniel Huber, Savita Mathur, Victor See, Jennifer L. van Saders, Derek Buzasi, Keivan G. Stassun, Sarbani Basu, Warrick H. Ball, Ricky Egeland, Timo Reinhold
Publikováno v:
Metcalfe, T S, Van Saders, J L, Basu, S, Buzasi, D, Drake, J J, Egeland, R, Huber, D, Saar, S H, Stassun, K G, Ball, W H, Campante, T L, Finley, A J, Kochukhov, O, Mathur, S, Reinhold, T, See, V, Baliunas, S & Soon, W 2021, ' Magnetic and Rotational Evolution of ρ CrB from Asteroseismology with TESS ', Astrophysical Journal, vol. 921, no. 2, 122 . https://doi.org/10.3847/1538-4357/ac1f19
The Astrophysical Journal
The Astrophysical Journal, 2021, 921, ⟨10.3847/1538-4357/ac1f19⟩
The Astrophysical Journal
The Astrophysical Journal, 2021, 921, ⟨10.3847/1538-4357/ac1f19⟩
During the first half of main-sequence lifetimes, the evolution of rotation and magnetic activity in solar-type stars appears to be strongly coupled. Recent observations suggest that rotation rates evolve much more slowly beyond middle-age, while ste
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::8f84de457ef35e14294dd0c7b7367b52
https://pure.au.dk/portal/da/publications/magnetic-and-rotational-evolution-of--crb-from-asteroseismology-with-tess(5cbda709-5ee5-4492-9c7b-cc71ca37bb2b).html
https://pure.au.dk/portal/da/publications/magnetic-and-rotational-evolution-of--crb-from-asteroseismology-with-tess(5cbda709-5ee5-4492-9c7b-cc71ca37bb2b).html
Autor:
Arnold O. Benz, R. Brajša, Hans-Günter Ludwig, Steven H. Saar, Caius L. Selhorst, Säm Krucker, Davor Sudar, Ivica Skokić
Aims. The main aim of the present analysis is to decipher (i) the small-scale bright features in solar images of the quiet Sun and active regions obtained with the Atacama Large Millimeter/submillimeter Array (ALMA) and (ii) the ALMA correspondence o
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::17fd4eda08bbafe8db0bee87b2be82f5
https://doi.org/10.1051/0004-6361/201936231
https://doi.org/10.1051/0004-6361/201936231
Autor:
Giuseppina Micela, Rosario Cosentino, D. W. Latham, Adriano Ghedina, Heather M. Cegla, David F. Phillips, D. Charbonneau, Samantha Thompson, Steven H. Saar, Timothy Milbourne, C. H. Li, M. Lopez-Morales, Alessandro Sozzetti, C. Lovis, Andrew Szentgyorgyi, François Bouchy, Christopher A. Watson, M. Gonzalez, Stéphane Udry, Emilio Molinari, M. L. Palumbo, N. Buchschacher, Andrew Collier Cameron, Ken Rice, Jesus Maldonado, J. Costes, Francesco Pepe, Alex Glenday, Massimo Cecconi, L. Malavolta, Xavier Dumusque, Raphaëlle D. Haywood, D. Segransan, G. Piotto, M. Mayor, Annelies Mortier, Dimitar Sasselov, Nicholas Langellier, Ronald L. Walsworth, Marcello Lodi
Publikováno v:
BASE-Bielefeld Academic Search Engine
Milbourne, T W, Haywood, R D, Phillips, D F, Saar, S H, Cegla, H M, Cameron, A C, Costes, J, Dumusque, X, Langellier, N, Latham, D W, Maldonado, J, Malavolta, L, Mortier, A, Palumbo, M L III, Thompson, S, Watson, C A, Bouchy, F, Buchschacher, N, Cecconi, M, Charbonneau, D, Cosentino, R, Ghedina, A, Glenday, A G, Gonzalez, M, Li, C-H, Lodi, M, López-Morales, M, Lovis, C, Mayor, M, Micela, G, Molinari, E, Pepe, F, Piotto, G, Rice, K, Sasselov, D, Ségransan, D, Sozzetti, A, Szentgyorgyi, A, Udry, S & Walsworth, R L 2019, ' HARPS-N Solar RVs Are Dominated by Large, Bright Magnetic Regions ', The Astrophysical Journal, vol. 874, no. 1 . https://doi.org/10.3847/1538-4357/ab064a
Milbourne, T W, Haywood, R D, Phillips, D F, Saar, S H, Cegla, H M, Cameron, A C, Costes, J, Dumusque, X, Langellier, N, Latham, D W, Maldonado, J, Malavolta, L, Mortier, A, Palumbo, M L III, Thompson, S, Watson, C A, Bouchy, F, Buchschacher, N, Cecconi, M, Charbonneau, D, Cosentino, R, Ghedina, A, Glenday, A G, Gonzalez, M, Li, C-H, Lodi, M, López-Morales, M, Lovis, C, Mayor, M, Micela, G, Molinari, E, Pepe, F, Piotto, G, Rice, K, Sasselov, D, Ségransan, D, Sozzetti, A, Szentgyorgyi, A, Udry, S & Walsworth, R L 2019, ' HARPS-N Solar RVs Are Dominated by Large, Bright Magnetic Regions ', The Astrophysical Journal, vol. 874, no. 1 . https://doi.org/10.3847/1538-4357/ab064a
State-of-the-art radial-velocity (RV) exoplanet searches are currently limited by RV signals arising from stellar magnetic activity. We analyze solar observations acquired over a 3 yr period during the decline of Carrington Cycle 24 to test models of
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::9121ce527c2b3f924dcbafc9c92a0a8d
https://hdl.handle.net/10023/17411
https://hdl.handle.net/10023/17411
Autor:
C. Lovis, Giuseppina Micela, N. Buchschacher, David F. Phillips, Timothy Milbourne, Steven H. Saar, Luca Malavolta, Marcello Lodi, Christopher A. Watson, Emilio Molinari, Stéphane Udry, Annelies Mortier, Nicholas Langellier, Ronald L. Walsworth, M. Gonzalez, Rosario Cosentino, D. W. Latham, D. Charbonneau, Alessandro Sozzetti, Ken Rice, Samantha Thompson, Jesus Maldonado, A. Collier Cameron, Dimitar Sasselov, M. Lopez-Morales, C. H. Li, Andrew Szentgyorgyi, Heather M. Cegla, Xavier Dumusque, Alex Glenday, Raphaëlle D. Haywood, Ennio Poretti, Massimo Cecconi, A. Coffinet, Adriano Ghedina, J. Costes, Francesco Pepe
Publikováno v:
Cameron, A C, Mortier, A, Phillips, D, Dumusque, X, Haywood, R D, Langellier, N, Watson, C A, Cegla, H M, Costes, J, Charbonneau, D, Coffinet, A, Latham, D W, Lopez-Morales, M, Malavolta, L, Maldonado, J, Micela, G, Milbourne, T, Molinari, E, Saar, S H, Thompson, S, Buchschacher, N, Cecconi, M, Cosentino, R, Ghedina, A, Glenday, A, Li, M G C-H, Li, C-H, Lodi, M, Lovis, C, Pepe, F, Poretti, E, Rice, K, Sasselov, D, Sozzetti, A, Szentgyorgyi, A, Udry, S & Walsworth, R 2019, ' Three years of Sun-as-a-star radial-velocity observations on the approach to solar minimum ', Monthly Notices of the Royal Astronomical Society . https://doi.org/10.1093/mnras/stz1215
BASE-Bielefeld Academic Search Engine
BASE-Bielefeld Academic Search Engine
The time-variable velocity fields of solar-type stars limit the precision of radial-velocity determinations of their planets' masses, obstructing detection of Earth twins. Since 2015 July we have been monitoring disc-integrated sunlight in daytime us
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::0d1aa7b35379584e243fcece6a71261d
http://hdl.handle.net/11577/3343498
http://hdl.handle.net/11577/3343498