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Related papers: Statistical properties of coronal hole rotation ra…

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Coronal holes (CHs) are darker than quiet Sun (QS) when observed in coronal channels. This study aims to understand the similarities and differences between CHs and QS in the transition region using the \ion{Si}{4}~1394~{\AA} line recorded…

Solar and Stellar Astrophysics · Physics 2021-02-17 Durgesh Tripathi , V. N. Nived , Sami K Solanki

The relationship between the peak velocities of high-speed solar wind streams near Earth and the areas of their solar source regions, i.e., coronal holes, has been known since the 1970s, but it is still physically not well understood. We…

Solar and Stellar Astrophysics · Physics 2020-07-10 Stefan J. Hofmeister , Astrid M. Veronig , Stefaan Poedts , Evangelia Samara , Jasmina Magdalenic

We will use new data from the High-resolution Coronal Imager (Hi-C) with unprecedented spatial resolution of the solar corona to investigate the structure of coronal loops down to 0.2 arcsec. During a rocket flight Hi-C provided images of…

Solar and Stellar Astrophysics · Physics 2015-06-16 H. Peter , S. Bingert , J. A. Klimchuk , C. de Forest , J. W. Cirtain , L. Golub , A. R. Winebarger , K. Kobayashi , K. E. Korreck

Context. The corona of the Sun is the part of the solar atmosphere with temperatures of over one million Kelvin, which needs to be heated internally in order to exist. This heating mechanism remains a mystery; we see large magnetically…

Solar and Stellar Astrophysics · Physics 2023-11-03 I. Kraus , Ph. -A. Bourdin , J. Zender , M. Bergmann , A. Hanslmeier

The rotation rates in the deep interior and at the surface of 22 main-sequence stars with masses between $1.0$ and $1.6\,{\rm M}_{\odot}$ are constrained by combining asteroseismological analysis with spectroscopic measurements. The…

Solar and Stellar Astrophysics · Physics 2015-08-06 O. Benomar , M. Takata , H. Shibahashi , T. Ceillier , R. A. Garcia

Coronal holes are the darkest and least active regions of the Sun, as observed both on the solar disk and above the solar limb. Coronal holes are associated with rapidly expanding open magnetic fields and the acceleration of the high-speed…

Solar and Stellar Astrophysics · Physics 2015-05-14 Steven R. Cranmer

The rotation of sunspots of 2 yr in two different solar cycles is studied with the data from the Helioseismic and Magnetic Imager on board the \it Solar Dynamics Observatory \rm and the Michelson Doppler Imager instrument on board the \it…

Solar and Stellar Astrophysics · Physics 2016-07-29 Jianchuan Zheng , Zhiliang Yang , Kaiming Guo , Haimin Wang , Shuo Wang

We develop a reliable, fully automatic method for the detection of coronal holes, that provides consistent full-disk segmentation maps over the full solar cycle and can perform in real-time. We use a convolutional neural network to identify…

Solar and Stellar Astrophysics · Physics 2021-08-09 R. Jarolim , A. M. Veronig , S. Hofmeister , S. G. Heinemann , M. Temmer , T. Podladchikova , K. Dissauer

Understanding coronal structure and dynamics can be facilitated by analyzing green-line emission, which enables the investigation of diverse coronal structures such as coronal loops, streamers, coronal holes, and various eruptions in the…

Solar and Stellar Astrophysics · Physics 2024-11-27 Jacob Oloketuyi , Yu Liu , Linhua Deng , Abouazza Elmhamdi , Fengrong Zhu , Ayodeji Ibitoye , Opeyemi Omole , Feiyang Sha , Qiang Liu

We investigate the deflection and rotation behavior of 49 Earth-directed coronal mass ejections (CMEs) spanning the period from 2010 to 2020 aiming to understand the potential influence of coronal holes (CHs) on their trajectories. We…

Solar and Stellar Astrophysics · Physics 2026-04-30 Suresh Karuppiah , Mateja Dumbović , Karmen Martinić , Manuela Temmer , Stephan G. Heinemann , Bojan Vršnak

The daily sunspot numbers of the whole disk as well as the northern and southern hemispheres from January 1, 1945 to December 31, 2010 are used to investigate the temporal variation of the rotational cycle length through the continuous…

Solar and Stellar Astrophysics · Physics 2015-06-03 J. -L. Xie , X. -J. Shi , J. -C. Xu

Using the multi-wavelength data from the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO) spacecraft, we study a jet occurred in coronal hole near the northern pole of the Sun. The jet presented distinct…

Solar and Stellar Astrophysics · Physics 2015-06-03 Huadong Chen , Jun Zhang , Suli Ma

Context. Solar active regions are known to have jets. These jets are associated with heating and the release of particles into the solar wind. Aim. Our aim is to understand the spatial distribution of coronal jets within active regions to…

Solar and Stellar Astrophysics · Physics 2022-09-07 Jonas Odermatt , Krzysztof Barczynski , Louise K. Harra , Conrad Schwanitz , Säm Krucker

Decayless kink oscillations are omnipresent in the solar atmosphere and a viable candidate for coronal heating. Though there have been extensive studies of decayless oscillations in coronal loops with a few hundred Mm lengths, the…

The aim of this paper is to investigate whether there are any 11-yr or quasi-biennial solar cycle-related variations in solar rotational splitting frequencies of low-degree solar p modes. Although no 11-yr signals were observed, variations…

Solar and Stellar Astrophysics · Physics 2015-06-04 Anne-Marie Broomhall , David Salabert , William J. Chaplin , Rafael A. Garcia , Yvonne Elsworth , Rachel Howe , Savita Mathur

Coronal density, temperature and heat flux distributions for the equatorial and polar corona have been deduced by Lemaire [2012] from Saito's model of averaged coronal white light (WL) brightness and polarization observations. They are…

Solar and Stellar Astrophysics · Physics 2015-06-05 V. Pierrard , K. Borremans , J. F. Lemaire

The solar tachocline at the bottom of the convection zone is an important region for the dynamics of the Sun and the solar dynamo. In this region, the sound speed inferred by global helioseismology exhibits a bump of approximately 0.4%…

Solar and Stellar Astrophysics · Physics 2009-09-28 Junwei Zhao , Thomas Hartlep , A. G. Kosovichev , N. N. Mansour

We use time series observations from the SOHO and Yohkoh spacecraft to study solar polar rays. Contrary to our expectations, we find that the rays are associated with active regions on the sun and are not features of the polar coronal…

Astrophysics · Physics 2009-10-31 Jing Li , David Jewitt , Barry LaBonte

Helioseismology revealed an increase in the rotation rate with depth just beneath the solar surface. The relative magnitude of the radial shear is almost constant with latitude. This rotational state can be interpreted as a consequence of…

Solar and Stellar Astrophysics · Physics 2016-06-01 Leonid Kitchatinov

Solar-cycle related variation of differential rotation is investigated through analyzing the rotation rates of magnetic fields, distributed along latitudes and varying with time at the time interval of August 1976 to April 2008. More…

Solar and Stellar Astrophysics · Physics 2015-06-16 K. J. Li , X. J. Shi , J. L. Xie , P. X. Gao , H. F. Liang , L. S. Zhan , W. Feng