Search Publications
VFISV: Very Fast Inversion of the Stokes Vector for the Helioseismic and Magnetic Imager
Schou, J.; Kubo, M.; Borrero, J. M. +4 more
In this paper we describe in detail the implementation and main properties of a new inversion code for the polarized radiative transfer equation (VFISV: Very Fast Inversion of the Stokes Vector). VFISV will routinely analyze pipeline data from the Helioseismic and Magnetic Imager (HMI) on-board of the Solar Dynamics Observatory (SDO). It will prov…
Small-Scale Flux Emergence Observed Using Hinode/SOT
Parnell, C. E.; Thornton, L. M.
The aim of this paper is to determine the flux emergence rate due to small-scale magnetic features in the quiet Sun using high-resolution Hinode SOT NFI data. Small-scale magnetic features are identified in the data using two different feature identification methods (clumping and downhill); then three methods are applied to detect flux emergence e…
Coronal-Temperature-Diagnostic Capability of the Hinode/ X-Ray Telescope Based on Self-Consistent Calibration
Weber, M.; Golub, L.; Bando, T. +10 more
The X-Ray Telescope (XRT) onboard the Hinode satellite is an X-ray imager that observes the solar corona with unprecedentedly high angular resolution (consistent with its 1″ pixel size). XRT has nine X-ray analysis filters with different temperature responses. One of the most significant scientific features of this telescope is its capability of d…
Multiwavelength Observations of a Failed Flux Rope in the Eruption and Associated M-Class Flare from NOAA AR 11045
Filippov, B.; Erdélyi, R.; Kumar, Pankaj +2 more
We present the multiwavelength observations of a flux rope that was trying to erupt from NOAA AR 11045 and the associated M-class solar flare on 12 February 2010 using space-based and ground-based observations from TRACE, STEREO, SOHO/MDI, Hinode/XRT, and BBSO. While the flux rope was rising from the active region, an M1.1/2F class flare was trigg…
Coronal Dimmings and the Early Phase of a CME Observed with STEREO and Hinode/EIS
Möstl, C.; Temmer, M.; Veronig, A. M. +2 more
We investigate the early phase of the 13 February 2009 coronal mass ejection (CME). Observations with the twin STEREO spacecraft in quadrature allow us to compare for the first time in one and the same event the temporal evolution of coronal EUV dimmings, observed simultaneously on-disk and above-the-limb. We find that these dimmings are synchroni…
Nonlinear Force-Free and Potential-Field Models of Active-Region and Global Coronal Fields during the Whole Heliosphere Interval
Canou, A.; Amari, T.; Petrie, G. J. D.
Between 24 March 2008 and 2 April 2008, the three active regions (ARs) NOAA 10987, 10988 and 10989 were observed daily by the Synoptic Optical Long-term Investigations of the Sun (SOLIS) Vector Spectro-Magnetograph (VSM) while they traversed the solar disk. We use these measurements and the nonlinear force-free magnetic field code XTRAPOL to recon…
Comparison of Nonlinear Force-Free Field and Potential Field in the Quiet Sun
Zhang, H. Q.; Su, J. T.; Liu, S.
In this paper, a potential field extrapolation and three nonlinear force-free (NLFF) field extrapolations (optimization, direct boundary integral (DBIE), and approximate vertical integration (AVI) methods) are used to study the spatial configuration of magnetic field in the quiet Sun. It is found that differences in the computed field strengths am…
Non-Varying Granulation and Photospheric Network During the Extended 2007 - 2009 Solar Minimum
Utz, D.; Hanslmeier, A.; Muller, R.
We have analysed the wide band images taken by Hinode/SOT, in a blue continuum window and in the G-band, more or less on a daily basis in the frame of the synoptic program, to investigate the variation of the solar granulation and of the photospheric network with the activity cycle. A particular attention has been given to disentangle solar effect…
The Global Context of Solar Activity During the Whole Heliosphere Interval Campaign
Plunkett, S. P.; Webb, D. F.; Mandrini, C. H. +9 more
The Whole Heliosphere Interval (WHI) was an international observing and modeling effort to characterize the 3-D interconnected "heliophysical" system during this solar minimum, centered on Carrington Rotation 2068, March 20 - April 16, 2008. During the latter half of the WHI period, the Sun presented a sunspot-free, deep solar minimum type face. B…
Determining the Solar Source of a Magnetic Cloud Using a Velocity Difference Technique
Mandrini, C. H.; Gulisano, A. M.; Dasso, S. +3 more
For large eruptions on the Sun, it is often a problem that the core dimming region cannot be observed due to the bright emission from the flare itself. However, spectroscopic data can provide the missing information through the measurement of Doppler velocities. In this paper we analyse the well-studied flare and coronal mass ejection that erupted…