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A well known behavior of EUV light curves of discrete coronal loops is that the peak intensities of cooler channels or spectral lines are reached at progressively later times than hotter channels. This time lag is understood to be the…

Solar and Stellar Astrophysics · Physics 2015-06-04 Nicholeen M. Viall , James A. Klimchuk , NASA Goddard Space Flight Center

The high temporal, spatial and spectral resolution of Interface Region Imaging Spectrograph (IRIS) has provided new insights into the understanding of different small-scale processes occurring at the chromospheric and transition region (TR)…

Solar and Stellar Astrophysics · Physics 2019-05-03 Nancy Narang , Vaibhav Pant , Dipankar Banerjee , Tom Van Doorsselaere

We report on the first Interface Region Imaging Spectrograph (IRIS) study of cool transition region loops. This class of loops has received little attention in the literature. A cluster of such loops was observed on the solar disk in active…

Solar and Stellar Astrophysics · Physics 2015-09-09 Zhenghua Huang , Lidong Xia , Bo Li , Maria S. Madjarska

The relationships among coronal loop structures at different temperatures is not settled. Previous studies have suggested that coronal loops in the core of an active region are not seen cooling through lower temperatures and therefore are…

Solar and Stellar Astrophysics · Physics 2011-02-11 Ignacio Ugarte-Urra , Harry P. Warren , David H. Brooks

High-resolution observations of dynamic phenomena give insight into properties and processes that govern the low solar atmosphere. We present the analysis of jet-like phenomena emanating from a penumbral foot-point in active region (AR)…

Solar and Stellar Astrophysics · Physics 2020-10-09 Llŷr Dafydd Humphries , Erwin Verwichte , David Kuridze , Huw Morgan

Despite intensive studies of kink oscillations of coronal loops in the last decade, a large scale statistically significant investigation of the oscillation parameters has not been made using data from the Solar Dynamics Observatory (SDO).…

Solar and Stellar Astrophysics · Physics 2016-01-13 C. R. Goddard , G. Nistic`o , V. M. Nakariakov , I. V. Zimovets

In this paper, we report our multiwavelength observations of the large-amplitude longitudinal oscillations of a filament on 2015 May 3. Located next to active region 12335, the sigmoidal filament was observed by the ground-based H$\alpha$…

Solar and Stellar Astrophysics · Physics 2017-06-21 Q. M. Zhang , T. Li , R. S. Zheng , Y. N. Su , H. S. Ji

High-frequency wave phenomena present a great deal of interest as one of the possible candidates to contribute to the energy input required to heat the corona as a part of the AC heating theory. However, the resolution of imaging…

Solar and Stellar Astrophysics · Physics 2023-04-05 Elena Petrova , Norbert Magyar , Tom Van Doorsselaere , David Berghmans

I report on observations of a set of magnetic loops above a region with late-phase flux emergence taken by IRIS, Hinode and SDO. The loop system consists of many transition region loop threads with size of 5--12\arcsec\ in length and…

Solar and Stellar Astrophysics · Physics 2019-01-09 Zhenghua Huang

Three-minute oscillations over sunspot's umbra in AR 11131 were observed simultaneously in UV/EUV emission by SDO/AIA and in radio emission by Nobeyama Radioheliograph (NoRH). We use 24-hours series of SDO and 8-hours series of NoRH…

Solar and Stellar Astrophysics · Physics 2015-05-30 V. E. Reznikova , K. Shibasaki , R. A. Sych , V. M. Nakariakov

Evidence of flare induced, large-amplitude, decay-less transverse oscillations is presented. A system of multi-thermal coronal loops as observed with the Atmospheric Imaging Assembly (AIA), exhibit decay-less transverse oscillations after a…

Solar and Stellar Astrophysics · Physics 2021-08-04 Sudip Mandal , Hui Tian , Hardi Peter

Aims. To study intensity oscillations in the solar chromosphere/corona above a quiet-Sun magnetic network. Methods. We analyse the time series of He II 256.32, Fe XI 188.23 and Fe XII 195.12 spectral lines observed by EUV Imaging…

Astrophysics · Physics 2009-11-13 A. K. Srivastava , D. Kuridze , T. V. Zaqarashvili , B. N. Dwivedi

We analyze a time sequence of He II 256.32 angstrom images obtained with EIS/Hinode, sampling a small magnetic loop in magnetic network. Wavelet analysis indicates 11-min periodicity close to the loop apex. We interprete this oscillation as…

Solar and Stellar Astrophysics · Physics 2015-05-13 A. K. Srivastava , D. Kuridze , T. V. Zaqarashvili , B. N. Dwivedi , B. Rani

Standing slow mode waves in hot flaring loops are exclusively observed in spectrometers and are used to diagnose the magnetic field strength and temperature of the loop structure. Due to the lack of spatial information, the longitudinal…

Solar and Stellar Astrophysics · Physics 2015-07-15 D. Yuan , T. Van Doorsselaere , D. Banerjee , P. Antolin

The Extreme ultraviolet Imaging Spectrometer (EIS) on board Hinode is the first solar telescope to obtain wide slit spectral images that can be used for detecting Doppler flows in transition region and coronal lines on the Sun and to relate…

Astrophysics · Physics 2009-11-13 D. E. Innes , R. Attie , H. Hara , M. S. Madjarska

We study plasma flows along selected coronal loops in NOAA Active Region 10926, observed on 3 December 2006 with Hinode's EUV Imaging Spectrograph (EIS). From the shape of the loops traced on intensity images and the Doppler shifts measured…

Solar and Stellar Astrophysics · Physics 2015-06-05 P. Syntelis , C. Gontikakis , M. K. Georgoulis , C. E. Alissandrakis , K. Tsinganos

We use coronal imaging observations with SDO/AIA, and Hinode/EIS spectral data, to explore the potential of narrow band EUV imaging data for diagnosing the presence of hot (T >~5MK) coronal plasma in active regions. We analyze observations…

Solar and Stellar Astrophysics · Physics 2015-06-04 Paola Testa , Fabio Reale

We aim to ascertain the physical parameters of a propagating wave over the solar disk detected by the Interface Region Imaging Spectrograph (IRIS). Using imaging data from the IRIS and the Solar Dynamic Observatory (SDO), we tracked bright…

Solar and Stellar Astrophysics · Physics 2018-03-21 B. Zhang , Y. J. Hou , J. Zhang

Observations of recurrent explosive events (EEs) with time scale of 3-5 minutes are reported. These EEs have been observed with the Interface Region Imaging Spectrograph (IRIS) and have a spatial dimension of $\sim1.5"$ along the slit. The…

Solar and Stellar Astrophysics · Physics 2015-08-14 G. R. Gupta , Durgesh Tripathi

One of the most interesting discoveries of the X-ray Telescope and EUV Imaging Spectrometer (EIS) on board the Hinode solar observatory is the presence of persistent high temperature high speed outflows from the edges of active regions.…

Solar and Stellar Astrophysics · Physics 2015-05-20 David H. Brooks , Harry P. Warren