Search Publications
Photometric Oscillations of Low-Luminosity Red Giant Stars
Gilliland, Ronald L.
I present details of the variations of several hundred red giant stars on timescales of a few hours to a few days from Hubble Space Telescope (HST) observations of a low-extinction galactic bulge sample from an intensive seven-day campaign. Variations in the red giants are shown to be a strong function of position within the color-magnitude diagra…
Near-surface heating on Enceladus and the south polar thermal anomaly
Nimmo, F.; Roberts, J. H.
Strike-slip motion is predicted to be a consequence of diurnal tidal stresses in most satellites of the outer solar system. Such motion can lead to near-surface heating through friction or viscous dissipation. Here we discuss the effect of near-surface shear heating on convection in the underlying ice shells of icy satellites. We present models of…
Electron trapping around a magnetic null
Escoubet, C. P.; Dandouras, I.; Glassmeier, K. -H. +18 more
Magnetic reconnection is an important process in astrophysical, space and laboratory plasmas. The magnetic null pair structure is theoretically suggested to be a crucial feature of the three-dimensional magnetic reconnection. The physics around the null pair, however, has not been explored in combination with the magnetic field configuration deduc…
Long-period oscillations in solar coronal bright points
Li, S.; Tian, H.; Xia, L. -D.
Aims: By analyzing TRACE (Transition Region and Coronal Explorer) data, we investigate intensity oscillations in coronal bright points (BPs) as well as the underlying chromosphere.
Methods: A Fourier analysis is applied to a sequence of images observed in the 195 Å and 1216 Å passbands of TRACE. We produce images of Fourier power in three diff…
A Search for New Galactic Magnetars in Archival Chandra and XMM-Newton Observations
Miller, J. M.; Muno, M. P.; Gaensler, B. M. +2 more
We present constraints on the number of Galactic magnetars, which we have established by searching for sources with periodic variability in 506 archival Chandra observations and 441 archival XMM-Newton observations of the Galactic plane (| b| < 5°). Our search revealed four sources with periodic variability on timescales of 200-5000 s, all of w…
Non-Gaussian Line Profiles in a Large Solar Flare Observed on 2006 December 13
Mariska, J. T.; Hara, H.; Watanabe, T. +4 more
We have studied the characteristics of the non-Gaussian line profile of the Fe XIV 274.20 Å line in and around a flare arcade. We found that broad non-Gaussian line profiles associated with redshifts are observed in the flare arcade. There were two typical types of broad line profiles. One was a distorted line profile caused by multiple flows, and…
A Statistical Study of Solar Active Regions That Produce Extremely Fast Coronal Mass Ejections
Wang, Yuming; Zhang, Jie
We present statistical results on the properties of the solar source regions that produced the 57 fastest (>=1500 km s-1) front-side coronal mass ejections (CMEs) from 1996 June to 2007 January. The properties of these fast-CME-producing regions, 35 in total, are compared with those of all 1143 active regions (ARs) in the period stud…
INTEGRAL observations of the variability of OAO 1657-415
Klochkov, D.; Santangelo, A.; Wilms, J. +7 more
Context: The Galactic Plane Scan (GPS) was one of the core observation programmes of the INTEGRAL satellite. The highly variable accreting pulsar
Aims: We investigate the spectral and timing properties of OAO 1657-415 and their variability on short and long time scales in …
X-ray spectral variability in PG 1535+547: the changing look of a ``soft X-ray weak'' AGN
Cappi, M.; Vignali, C.; Schartel, N. +5 more
Context:
A New Forecasting Index for Solar Wind Velocity Based on EIT 284 Å Observations
Luo, Bingxian; Zhong, Qiuzhen; Liu, Siqing +1 more
Various solar wind forecasting methods have been developed during the past decade, such as the Wang - Sheeley model and the Hakamada - Akasofu - Fry Version 2 (HAFv2) model. Also, considerable correlation has been found between the solar wind speed v and the coronal hole (CH) area AM on the visible side of the Sun, showing quantitative …