From RHESSI Wiki
Welcome to the RHESSI Science Nuggets: science notes from RHESSI. The following is a time-ordered list of the latest Nuggets added to the wiki. An alphabetical list of wiki Nuggets is also available. If you are looking for older Nuggets than please visit the original series of RHESSI Science Nuggets and use the search facilities there; for this new series of Nuggets in the Wiki format, use your browser's search facility for title words or authors.
We welcome volunteer authors - please see our page of help for authors.
Please note that each Nugget page has a Discussion page, which sometimes has really interesting information.
193
| Passages of Electron Beams
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11 February 2013 by Bin Chen
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New VLA capability for imaging spectroscopy shows several remarkable features of type III bursts. Click the title to read more.
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192
| Kappa Distribution
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21 January 2013 by Mitsuo Oka
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A simpler function fits both thermal and nonthermal RHESSI spectral ranges. Click the title to read more.
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190
| Flare Productivity
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27 December 2012 by Hugh Hudson and Lyndsay Fletcher
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An anomalous change in flare productivity per active region. Click the title to read more.
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189
| FOXSI Success
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27 December 2012 by Lindsay Glesener and Säm Krucker
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The FOXSI rocket soars, and a flare occurs on schedule. Click the title to read more.
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188
| "Impulse Response Flares" and Gamma Rays
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13 November 2012 by Stephen White and Hugh Hudson
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A simplifying paradigm may describe acceleration to the highest energies in flares. Click the title to read more.
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186
| Photospheric Temperature Gradient
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22 October 2012 by Martin Fivian and Hugh Hudson
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RHESSI observes the photosphere with exquisite precision. Click the title to read more.
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184
| New TGFs Found in the RHESSI Data
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10 September 2012 by Thomas Gjesteland and Nikolai Østgaard
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RHESSI sees many, many gamma-ray flashes from lightning. Click the title to read more.
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183
| The RHESSI Flare Catalog
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29 August 2012 by Jim McTiernan and Hugh Hudson
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The Catalog is a powerful and easy-to-use access tool for the RHESSI flare observations. Click the title to read more.
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182
| RHESSI Catches Gamma-Ray Bursts
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15 August 2012 by Jakub Ripa
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RHESSI catches gamma-ray bursts, and they come in three flavors. Click the title to read more.
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181
| Dense Loop Flares
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6 August 2012 by Jingnan Guo and Gordon Emslie
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Direct electron mapping teaches us about the structure of electron acceleration in flares. Click the title to read more.
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180
| The Slowest Flare
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23 July 2012 by Sam Freeland and Hugh Hudson
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A flare with an exceptionally slow rise phase, more than 5 hours in GOES 1-8 A soft X-rays. Click the title to read more.
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179
| Dimmings and Sustained Gamma-Ray Events
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25 June 2012 by Hugh Hudson and Nicola Omodei
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Coronal disruptions reveal themselves as depletions and gamma-ray emissions. Click the title to read more.
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178
| Flare Nimbus
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14 June 2012 by Susan McKenna-Lawlor
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The Flare Nimbus, its history and significance. Click the title to read more.
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174
| A Shocking Type II
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30 April 2012 by Hazel Bain, Säm Krucker and Lyndsay Glesener
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The properties of global coronal waves sorted out. Click the title to read more.
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173
| RHESSI and IRIS
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16 April 2012 by Hugh Hudson
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Flare gold at the foot of the rainbow. Click the title to read more.
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172
| A New Day Dawns
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26 March 2012 by Dale Gary
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Soon, true microwave imaging spectroscopy. Click the title to read more.
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171
| An Fe Cascade
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12 March 2012 by Hugh Hudson
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Iron everywhere in the EVE spectra. Click the title to read more.
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169
| RHESSI's Tenth Anniversary
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15 February 2012 by B. Dennis and R. Lin
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On RHESSI's tenth, a top-ten discovery list. Click the title to read more.
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168
| Supra-Arcade Downflows
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23 January 2012 by S. Savage and D. McKenzie
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A re-interpretation of the famous SAD tadpoles. Click the title to read more.
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166
| No Hard X-rays from Comet Lovejoy
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19 December 2011 by H. Hudson and P. Saint-Hilaire
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An amazing sungrazing comet, but not detectable at high energies. Click the title to read more.
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163
| X-ray and H-alpha Flare Impulses
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14 November 2011 by K. Radziszewski and P. Rudawy
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Strikingly precise correlations of H-alpha kernels and hard X-ray bursts. Click the title to read more.
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160
| A Flare in 3D
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10 October 2011 by Hugh Hudson and Juan Carlos Martinez Oliveros
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Solar astrometry in 3D. Click the title to read more.
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159
| Solar Max Arrives
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28 September 2011 by Hugh Hudson and Richard Schwartz
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Seven X-class flares already in 2011. Click the title to read more.
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155
| Hard X-rays and Sympathy
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13 July 2011 by Hugh Hudson
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A hard X-ray spike elicits a sympathetic response. Click the title to read more.
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154
| Suzaku Microflares
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30 June 2011 by S. Ishikawa
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Microflares too have powerful particle acceleration. Click the title to read more.
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153
| Acceleration without Heating
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13 June 2011 by G. Fleishman & E. Kontar
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Strong hard X-rays and weak soft X-rays - breaking the paradigm?. Click the title to read more.
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151
| EVE/ESP and the Neupert Effect
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9 May 2011 by H. Hudson
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The Neupert Effect works, sort of, in a limb gamma-ray flare. Click the title to read more.
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146
| M is for Magnifique Part Deux
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22 February 2011 by Steven Christe and Andrew Inglis
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A type II radio burst but no CME and introducing a new way to search for waves in SDO. (CORRECTION There is a CME!). Click the title to read more.
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145
| At last, the EUV Spectrum
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8 February 2011 by Hugh Hudson
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The main flare radiated energy is not in the EUV. Click the title to read more.
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144
| Black and White Flares
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24 January 2011 by Juan Carlos Martinez Oliveros and Charles Lindsey
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HMI sees a black-light flare (?). Click the title to read more.
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142
| Brilliant Timing
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20 December 2010 by Säm Krucker and Hugh Hudson
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Hinode and RHESSI observations strain the credibility of the thick-target model. Click the title to read more.
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141
| M is for Magnifique
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6 December 2010 by Steven Christe and Andrew Inglis
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RHESSI and SDO see a remarkable flare. Click the title to read more.
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140
| Major Flare Watch Evaluation
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15 November 2010 by Dick Canfield and Shaun Bloomfield
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How well the Chief Observers do. Click the title to read more.
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139
| But there was a bigger one
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8 November 2010 by Hugh Hudson and Lindsay Glesener
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A cycle 24 coronal hard X-ray event. Click the title to read more.
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138
| SDO EVE Flare Observation
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18 October 2010 by Phil Chamberlin and Tom Woods
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Introducing EVE spectroscopy of flares. Click the title to read more.
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137
| Sector Boundaries and RHESSI Flares
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4 October 2010 by Leif Svalgaard and Iain Hannah
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The interplanetary magnetic sectors seen in RHESSI flare statistics. Click the title to read more.
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136
| Quiet Sun III
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27 September 2010 by Iain Hannah and Hugh Hudson
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The quiet Sun can be an X-ray source. Click the title to read more.
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135
| The X-ray Limb
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6 September 2010 by Hugh Hudson and Gordon Hurford
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RHESSI gets to determine RSun. Click the title to read more.
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134
| Fast electrons relaxing
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23 August 2010 by Alec MacKinnon
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What do electrons do to relax?. Click the title to read more.
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133
| Chromospheric Plasma Parameters
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2 August 2010 by Stephanie Chow and Hugh Hudson
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Semi-empirical models of the chromosphere and plasma physics. Click the title to read more.
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132
| Harmonic Oscillations
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12 July 2010 by Ivan Zimovets and Andrew Inglis
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RHESSI rotation and nutation are necessary, but may complicate time-series analysis. Click the title to read more.
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131
| Cloudy SolarSoftware
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5 July 2010 by Laszlo Etesi and Brian Dennis
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The Cloud helps with access to data in the Virtual Solar Observatory. Click the title to read more.
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129
| Kernels and Ribbons
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14 June 2010 by Jiong QIU
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A clue to the differences between footpoints and ribbons. Click the title to read more.
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128
| Awesome Stellar Flare Spectra
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2 June 2010 by Adam Kowalski and Suzanne Hawley
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Can spectra of stellar flares be compared with images of solar flares?. Click the title to read more.
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127
| RHESSI's Anneal Adventure
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14 May 2010 by David Smith and Mark Lewis
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An operations anomaly leads to very successful improvements in RHESSI's performance. Click the title to read more.
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126
| History of Solar Oblateness
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26 April 2010 by Hugh Hudson and Jean-Pierre Rozelot
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RHESSI is contributing to an historically interesting and fundamental measurement. Click the title to read more.
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121
| Revisiting the SHH and SEP Link
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15 February 2010 by James Grayson and Säm Krucker
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RHESSI confirms the statistical link between flare hard X-ray spectral evolution and the acceleration of solar energetic particles. Click the title to read more.
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119
| Solar Hard X-ray Albedo
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18 January 2010 by Ed Schmahl and Gordon Hurford
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The elusive hard X-ray albedo source directly imaged at last!. Click the title to read more.
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118
| Cycle 24 has begun
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5 January 2010 by Hugh Hudson and Greg Slater
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Activity has increased sufficiently to state that we have left the doldrums at last.. Click the title to read more.
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116
| A tiny white-light flare
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7 December 2009 by Hugh Hudson
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A faint white-light flare serves as a model for the continuous energy distribution of the impulsive phase. Click the title to read more.
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115
| Dips and Waves
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23 November 2009 by Iain Hannah and Eduard Kontar
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The inclusion of wave-particle interactions appears to have a drastic effect on the classical thick-target model for flare hard X-ray emission.. Click the title to read more.
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113
| Imaging through visibility interpolation: uv-smooth
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23 October 2009 by A. M. Massone, M. Piana and A. G. Emslie
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RHESSI visibilities allow incredibly fast and robust imaging of solar flares. Read this nugget and you'll learn how.. Click the title to read more.
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112
| A Bad Time for Flares but a Good Time for Debris
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12 October 2009 by W. Dean Pesnell
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Orbital debris - dangerous to satellites in low Earth orbit - has been increasing recently. There are solar and non-solar reasons for this.. Click the title to read more.
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111
| RHESSI Deep Integrations
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29 September 2009 by Pascal Saint-Hilaire
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With an extremely deep integration, RHESSI may have detected X-rays from the base of a post-CME current sheet.. Click the title to read more.
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110
| RHESSI in Cycle 24
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14 September 2009 by Säm Krucker and Hugh Hudson
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RHESSI has successfully imaged one of the first flares of Cycle 24 in hard X-rays. Click the title to read more.
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108
| Solar Cosmic Rays of the GLE on 20 January 2005
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24 August 2009 by Sophie Masson & Ludwig Klein
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The relativistic solar protons of this event are related to an extended impulsive phase in the low corona. Click the title to read more.
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107
| CMEless Flares
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12 August 2009 by Hugh Hudson & Säm Krucker
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Major flares without CMEs have distinguishing X-ray properties. Click the title to read more.
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106
| Where are the flares
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21 July 2009 by Hugh Hudson & Leif Svalgaard
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The rise to maximum of Cycle 24 is much weaker, in terms of flare occurrence, than Cycle 23.. Click the title to read more.
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103
| STEREO observed stealth CME
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8 June 2009 by Eva Robbrecht
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Spectacular coronal effects with no chromospheric counterpart. Click the title to read more.
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102
| Hard X-ray Pulsations in Flares
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25 May 2009 by Andrew Inglis & Valery Nakariakov
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"Coronal seismology" via hard X-rays and microwaves. Click the title to read more.
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99
| Cycle 24 - don't panic yet!
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13 April 2009 by Leif Svalgaard and Hugh Hudson
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Cycle 24 is definitely late in arriving, and it's interesting, but this probably has happened before.. Click the title to read more.
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98
| Chree Analysis for Flares
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30 March 2009 by Hugh Hudson
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Exploring Chree analysis as applied to total solar irradiance measurements of flares.. Click the title to read more.
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97
| High Temperatures in Active Regions
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16 March 2009 by Jim McTiernan
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RHESSI discovers high temperatures, well above those of the corona, in quiescent active regions.. Click the title to read more.
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96
| The Jakimiec Track
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2 March 2009 by Hugh Hudson and Fabio Reale
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A recent re-analysis of the relationship between emission measure and temperature in flares stimulates this new nugget.. Click the title to read more.
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95
| Coronal implosion
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16 February 2009 by Rui Liu
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Though we expect flare implosions, we frequently observe explosions (i.e. eruptions). In this nugget, an observation of a contracting flare is described and analyzed.. Click the title to read more.
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94
| Other Discoveries from Carrington's Flare
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2 February 2009 by Hugh Hudson
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During the sesquicentennial of the Carrington flare, let us not forget how "Space Weather" got its start.. Click the title to read more.
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93
| Collapsing Traps
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21 January 2009 by Boris Somov and Hugh Hudson
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Large-scale plasma motions, as in magnetic reconnection, can directly accelerate high-energy particles.. Click the title to read more.
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92
| RHESSI Simulations of Complicated Flares
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5 January 2009 by Lyndsay Fletcher and Jim McTiernan
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Comparing RHESSI images with ones simulated from TRACE "white light" reveals striking similarities but intriguing differences.. Click the title to read more.
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91
| Cycle 24
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22 December 2008 by Hugh Hudson and Steven Christe
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Solar cycle 24 seems to be delayed. Where are the spots? This Nugget discusses the problem and reviews the recent Solar24 meeting, the first in our field to be Wikified.. Click the title to read more.
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90
| Inverse Compton X-rays from relativistic flare leptons
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1 December 2008 by Alec MacKinnon and Procheta Mallik
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Compton scattering makes the Sun visible at high energies, via processes related to the galactic cosmic rays. This is not your ordinary Bremsstrahlung.... Click the title to read more.
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89
| The Rise and Fall of The Low Energy Cut Off
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17 November 2008 by Ewan Dickson and Eduard Kontar
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Solar hard X-rays tend to have a power-law distribution in energy, implying infinite photon numbers at low energy (a "soft X-ray catastrophe"). Can we observe what limits this behavior?. Click the title to read more.
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88
| SEPs Link not Confirmed
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3 November 2008 by Gerry Share and Allan Tylka
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The spectral evolution of a solar hard X-ray burst may give a clue to the acceleration of solar energetic particles (SEPs). This RHESSI Science Nugget questions the validity of this predictor.. Click the title to read more.
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87
| The SphinX Instrument on CORONAS-PHOTON
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22 October 2008 by Janusz Sylwester and Ken Phillips
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An exciting new instrument will begin observations at an exciting time.. Click the title to read more.
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86
| The Good Guys and the Rascals
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13 October 2008 by B. Dabrowski and Arnold Benz
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Solar decimetric radio bursts - but only the good guys - correlate well with RHESSI hard X-rays.. Click the title to read more.
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85
| RHESSI Optical Images
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2008-09-29 by H. Jabran Zahid and Hugh Hudson
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RHESSI makes optical images as well as X-ray and gamma-ray ones. This Nugget explains how.. Click the title to read more.
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84
| Flare Plasma Abundances - New X-ray Observations
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2008-09-15 by Brian Dennis and Richard Starr
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MESSENGER is now exploring Mercury. It is also helping RHESSI to understand the solar X-ray spectrum and measure elemental abundances in flares.. Click the title to read more.
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83
| [[Hard X-rays from a Jet?]]
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2008-08-27 by Hazel Miller Bain and Lyndsay Fletcher
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Observations during the rise phase of a M5.4 flare suggests that hard x-rays may be associated with a jet observed by TRACE.. Click the title to read more.
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82
| [[Are Stellar Flares like Solar Flares?]]
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2008-08-11 by Hugh Hudson and Beate Stelzer
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In this Nugget, we explore an extrasolar flare (aka stellar flare). These stellar and solar flares are similar but it is often in subtle differences that we may learn the most.. Click the title to read more.
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80
| [[The McClymont Jerk]]
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2008-07-14 by Hugh Hudson and Brian Welsch
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The sudden energy release of a flare in the solar atmosphere has many consequences. One of them may be the McClymont Jerk.. Click the title to read more.
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For all previous Nuggets go to the old RHESSI Science Nugget Page.