Search Publications
Eruptive Flare, CME, and Shock Wave in the 25 August 2001 High-Energy Solar Event
Grechnev, V. V.; Kochanov, A. A.; Uralov, A. M.
The major SOL2001-08-25 event produced a fast coronal mass ejection (CME: 1430 km s−1), strong flare emissions in hard X-rays and γ -rays extending to high energies, and neutrons detected both on spacecraft and by a low-latitude neutron monitor. To supplement the probable picture of this outstanding event, we reconstruct kinematic plots…
NGC 2659: a probable binary cluster
Perren, G. I.; Pera, M. S.; Giorgi, E. E. +2 more
We present and discuss photometric data, proper motions and parallaxes in a field of a 30'x30' centred in the area centered in the open cluster NGC 2659 in the region of Vela. In recent papers on the same region evidences of the presence of another cluster close to the north-east of NGC 2659 have been reported. Data were extracted from Gaia EDR3 a…
Two-horn quiescent prominence observed in Hα and Mg II h&k lines with THEMIS and IRIS
Barczynski, Krzysztof; Schmieder, Brigitte; Labrosse, Nicolas +2 more
Context. Prominences are large magnetic structures in the corona filled by cool plasma with fast evolving fine structure.
Aims: We aim to better understand the plasma conditions in the fine structure of a quiescent prominence including two transient horns observed at the bottom of the cavity using the high resolution Interface Region Imaging …
High-contrast detection of exoplanets with a kernel-nuller at the VLTI
Ireland, Michael J.; Martinache, Frantz; N'Diaye, Mamadou +5 more
Context. The conventional approach to direct imaging is to use a single aperture coronagraph with wavefront correction via extreme adaptive optics (AO). Such systems are limited to observing beyond an inner working angle (IWA) of a few λ/D. Nulling interferometry with two or more apertures will enable detections of companions at separations at and…
The universality of power law slopes in the solar photosphere and transition region observed with HMI and IRIS
Aschwanden, Markus J.; Nhalil, Nived Vilangot
We compare the size distributions of self-organized criticality (SOC) systems in the solar photosphere and the transition region, using magnetogram data from Helioseismic and Magnetic Imager (HMI) and Interface Region Imaging Spectrograph (IRIS) data. For each dataset we fit a combination of a Gaussian and a power law size distribution function, w…
Testing ultralow amplitude Cepheid candidates in the Galactic disk by TESS and Gaia
Bódi, Attila; Szabó, Róbert; Molnár, László +1 more
Ultralow amplitude (ULA) and strange mode Cepheids are thought to be pulsating variable stars that are near to or are at the edges of the classical instability strip. Until now, a few dozen such variable star candidates have been found both in the Large Magellanic Cloud and the Milky Way. For the present work, we studied six ULA Cepheid candidates…
The SPHEREx Target List of Ice Sources (SPLICES)
Kang, Miju; Lee, Jeong-Eun; Lee, Ho-Gyu +16 more
One of the primary objectives of the SPHEREx mission is to understand the origin of molecules such as H2O, CO2, and other volatile compounds at the early stages of planetary system formation. Because the vast majority of these compounds-typically exceeding 95%-exist in the solid phase rather than the gaseous phase in the syst…
A Revised Graduated Cylindrical Shell Model and its Application to a Prominence Eruption
Zhang, Qing-Min; Hou, Zhen-Yong; Bai, Xian-Yong
In this paper, the well-known graduated cylindrical shell (GCS) model is slightly revised by introducing longitudinal and latitudinal deflections of prominences originating from active regions (ARs). Subsequently, it is applied to the three-dimensional (3D) reconstruction of an eruptive prominence in AR 13110, which produced an M1.7 class flare an…
Search for particle acceleration in two massive Wolf-Rayet stars using uGMRT observations
Tej, Anandmayee; del Palacio, Santiago; Saha, Anindya +4 more
Large wind kinetic power of Wolf-Rayet (WR) stars make them ideal targets in low radio frequencies to search for non-thermal emission due to relativistic particle acceleration. In this paper, we present observations of two WR stars, WR 114 and WR 142, in Band 4 (550-950 MHz) and Band 5 (1050-1450 MHz) using the upgraded Giant Meterwave Radio Teles…
New Method to Detect and Characterize Active Be Star Candidates in Open Clusters
Granada, Anahí; Eenmäe, Tõnis; Ghoreyshi, Maziar R. +1 more
With the aim of better understanding the physical conditions under which Be stars form and evolve, it is imperative to further investigate whether poorly studied young open clusters host Be stars. In this work, we explain how data from Gaia DR2 and DR3 can be combined to recover and characterize active Be stars in open clusters. We test our method…