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The solar photosphere is the visible surface of the Sun, where many bright granules, surrounded by narrow dark intergranular lanes, are observed everywhere. The granular pattern is a manifestation of convective motion at the photospheric…

Solar and Stellar Astrophysics · Physics 2017-02-15 T. Oba , Y. Iida , T. Shimizu

We present a method to derive outflow velocities in the solar corona using different data sets including solar wind mass flux coming from the SWAN/SOHO instrument, electron density values from LASCO-C2 and interplanetary solar wind…

Astrophysics · Physics 2009-11-13 E. Quemerais , R. Lallement , D. Koutroumpa , P. Lamy

We take advantage of the HMI/SDO instrument to study the naked emergence of active regions from the first imprints of the magnetic field on the solar surface. To this end, we followed the first 24 hours in the life of two rather isolated…

Solar and Stellar Astrophysics · Physics 2015-06-11 Rebecca Centeno

The Sun is the only star whose surface can be directly resolved at high resolution, and therefore constitutes an excellent test case to explore the physical origin of stellar radial-velocity (RV) variability. We present HARPS observations…

Earth and Planetary Astrophysics · Physics 2016-03-16 R. D. Haywood , A. Collier Cameron , Y. C. Unruh , C. Lovis , A. F. Lanza , J. Llama , M. Deleuil , R. Fares , M. Gillon , C. Moutou , F. Pepe , D. Pollacco , D. Queloz , D. Segransan

We studied the solar surface flows (differential rotation and meridional circulation) using a magnetic element feature tracking technique by which the surface velocity is obtained using magnetic field data. We used the line-of-sight…

Solar and Stellar Astrophysics · Physics 2018-09-05 Shinsuke Imada , Masashi Fujiyama

We developed a method to automatically detect and trace solar filaments in H\alpha\ full-disk images. The program is able not only to recognize filaments and determine their properties, such as the position, the area, the spine, and other…

Solar and Stellar Astrophysics · Physics 2015-06-15 Qi Hao , Cheng Fang , P. F. Chen

The Helioseismic and Magnetic Imager (HMI) onboard NASA's Solar Dynamics Observatory (SDO) produces estimates of the photospheric magnetic field which are a critical input to many space weather modelling and forecasting systems. The…

The detection of Earth-like planets with the radial-velocity method is currently limited by the presence of stellar activity signatures. On rotational timescales, spots and plages (or faculae) are known to introduce different RV signals,…

Solar and Stellar Astrophysics · Physics 2023-10-25 M. Cretignier , A. G. M. Pietrow , S. Aigrain

We present a dataset for investigating the impact of stellar activity on astrometric measurements using NASA's Solar Dynamics Observatory (SDO) images of the Sun. The sensitivity of astrometry for detecting exoplanets is limited by stellar…

Solar and Stellar Astrophysics · Physics 2023-10-20 Warit Wijitworasart , Zoe de Beurs , Andrew Vanderburg

Continuous high-cadence and high-spatial resolution Dopplergrams allow us to study sub-surface dynamics that may be further extended to explore precursors of visible solar activity on the surface. Since the p-mode power is absorbed in the…

Solar and Stellar Astrophysics · Physics 2016-01-20 Kiran Jain , S. C. Tripathy , B. Ravindra , R. Komm , F. Hill

Many phenomena taking place in the solar photosphere are controlled by plasma motions. Although the line-of-sight component of the velocity can be estimated using the Doppler effect, we do not have direct spectroscopic access to the…

Solar and Stellar Astrophysics · Physics 2017-08-02 A. Asensio Ramos , I. S. Requerey , N. Vitas

We have obtained H$\alpha$ high spatial and time resolution observations of the upper solar chromosphere and supplemented these with multi-wavelength observations from the Solar Dynamic Observatory (SDO) and the {\it Hinode}…

Solar and Stellar Astrophysics · Physics 2015-05-27 Damian J. Christian , David B. Jess , Patrick Antolin , Mihalis Mathioudakis

The south-north travel-time differences are measured by applying time-distance helioseismology to the MDI and HMI medium-degree Dopplergrams covering May 1996-April 2017. Our data analysis corrects for several sources of systematic effects:…

Solar and Stellar Astrophysics · Physics 2018-11-14 Zhi-Chao Liang , Laurent Gizon , Aaron C. Birch , Thomas L. Duvall , S. P. Rajaguru

We measure the Sun's velocity with respect to the Galactic halo using Gaia Early Data Release 3 (EDR3) observations of stellar streams. Our method relies on the fact that, in low-mass streams, the proper motion of stars should be directed…

Astrophysics of Galaxies · Physics 2020-12-11 Khyati Malhan , Rodrigo A. Ibata , Nicolas F. Martin

Context. It is possible to detect and track coronal bright points (CBPs) in SDO/AIA images. Combination of high resolution and high cadence provides a wealth of data that can be used to determine velocity flows on the solar surface with…

Solar and Stellar Astrophysics · Physics 2016-02-17 Davor Sudar , Steven H. Saar , Ivica Skokić , Ivana Poljančić Beljan , Roman Brajša

Solar inertial modes are quasi-toroidal modes of the Sun that are of practical interest as they allow probing the deep convection zone. Since 2010, solar images of the photospheric magnetic field are made available by HMI onboard the Solar…

Solar and Stellar Astrophysics · Physics 2025-02-10 Neelanchal Joshi , Zhi-Chao Liang , Damien Fournier , Laurent Gizon

Context: Solar sectoral Rossby waves have only recently been unambiguously identified in Helioseimsic and Magnetic Imager (HMI) and Michelson Doppler Imager (MDI) maps of flows near the solar surface. So far this has not been done with the…

Solar and Stellar Astrophysics · Physics 2020-03-18 Chris S. Hanson , Laurent Gizon , Zhi-Chao Liang

Since the Solar Dynamics Observatory (SDO) began recording ~ 1 TB of data per day, there has been an increased need to automatically extract features and events for further analysis. Here we compare the overall detection performance,…

Solar and Stellar Astrophysics · Physics 2011-09-05 Cis Verbeeck , Paul A. Higgins , Tufan Colak , Fraser T. Watson , Veronique Delouille , Benjamin Mampaey , Rami Qahwaji

We show that the motions of supergranules are consistent with a model in which they are simply advected by the axisymmetric flows in the Sun's surface shear layer. We produce a 10-day series of simulated Doppler images at a 15-minute…

Solar and Stellar Astrophysics · Physics 2015-05-19 David H. Hathaway , Peter E. Williams , Kevin Dela Rosa , Manfred Cuntz

The dynamics of prominence fine structures is a challenge to understand the formation of cool plasma prominence embedded in the hot corona. Recent observations from the high resolution Hinode/SOT telescope allow us to compute velocities…

Solar and Stellar Astrophysics · Physics 2015-05-14 B. Schmieder , R. Chandra , A. Berlicki , P. Mein