RHESSI Science Nuggets

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 old RHESSI Science Nuggets and use the search facilities there; for 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.

113	Imaging through visibility interpolation: uv-smooth
	23 October 2009 by A. M. Massone, M. Piana and A. G. Emslie
RHESSI visibilities allow incredibly fast and robust imaging of solar flares. Read this nugget and you'll learn how. Read more

112	A Bad Time for Flares but a Good Time for Debris
	12 October 2009 by W. Dean Pesnell
Orbital debris - dangerous to satellites in low Earth orbit - has been increasing recently. There are solar and non-solar reasons for this. Read more

111	RHESSI Deep Integrations
	29 September 2009 by Pascal Saint-Hilaire
With an extremely deep integration, RHESSI may have detected X-rays from the base of a post-CME current sheet. Read more

110	RHESSI in Cycle 24
	14 September 2009 by Säm Krucker and Hugh Hudson
RHESSI has successfully imaged one of the first flares of Cycle 24 in hard X-rays Read more

109	Confined Flares versus Eruptive Flares
	31 August 2009 by Jie Zhang
Eruptions tend not to happen for events that occur deep within an active region Read more

108	Solar Cosmic Rays of the GLE on 20 January 2005
	24 August 2009 by Sophie Masson & Ludwig Klein
The relativistic solar protons of this event are related to an extended impulsive phase in the low corona Read more

107	CMEless Flares
	12 August 2009 by Hugh Hudson & Säm Krucker
Major flares without CMEs have distinguishing X-ray properties Read more

106	Where are the flares
	21 July 2009 by Hugh Hudson & Leif Svalgaard
The rise to maximum of Cycle 24 is much weaker, in terms of flare occurrence, than Cycle 23. Read more

105	The 15.11 MeV Gamma-ray Line Detected?
	6 July 2009 by Brian Dennis
Carol Crannell's favorite gamma-ray line may have been detected at last Read more

104	Do solar decimetric spikes originate in coronal X-ray sources?
	22 June 2009 by Arnold Benz & Marina Battaglia
A surprise: radio and hard X-ray positions do not agree Read more

103	STEREO observed stealth CME
	8 June 2009 by Eva Robbrecht
Spectacular coronal effects with no chromospheric counterpart Read more

102	Hard X-ray Pulsations in Flares
	25 May 2009 by Andrew Inglis & Valery Nakariakov
"Coronal seismology" via hard X-rays and microwaves Read more

101	RHESSI microflares - Flare Cartoons and Reality
	11 May 2009 by Sigrid Berkebile-Stoiser
Do the standard cartoon models of solar flares describe the microflares as well? Read more

100	RHESSI - Concept to Fruition
	29 April 2009 by Brian Dennis & Bob Lin
A brief history of RHESSI. Read more

99	Cycle 24 - don't panic yet!
	13 April 2009 by Leif Svalgaard and Hugh Hudson
Cycle 24 is definitely late in arriving, and it's interesting, but this probably has happened before. Read more

98	Chree Analysis for Flares
	30 March 2009 by Hugh Hudson
Exploring Chree analysis as applied to total solar irradiance measurements of flares. Read more

97	High Temperatures in Active Regions
	16 March 2009 by Jim McTiernan
RHESSI discovers high temperatures, well above those of the corona, in quiescent active regions. Read more

96	The Jakimiec Track
	2 March 2009 by Hugh Hudson and Fabio Reale
A recent re-analysis of the relationship between emission measure and temperature in flares stimulates this new nugget. Read more

95	Coronal implosion
	16 February 2009 by Rui Liu
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. Read more

94	Other Discoveries from Carrington's Flare
	2 February 2009 by Hugh Hudson
During the sesquicentennial of the Carrington flare, let us not forget how "Space Weather" got its start. Read more

93	Collapsing Traps
	21 January 2009 by Boris Somov and Hugh Hudson
Large-scale plasma motions, as in magnetic reconnection, can directly accelerate high-energy particles. Read more

92	RHESSI Simulations of Complicated Flares
	5 January 2009 by Lyndsay Fletcher and Jim McTiernan
Comparing RHESSI images with ones simulated from TRACE "white light" reveals striking similarities but intriguing differences. Read more

91	Cycle 24
	22 December 2008 by Hugh Hudson and Steven Christe
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. Read more

90	Inverse Compton X-rays from relativistic flare leptons
	1 December 2008 by Alec MacKinnon and Procheta Mallik
Compton scattering makes the Sun visible at high energies, via processes related to the galactic cosmic rays. This is not your ordinary Bremsstrahlung... Read more

89	The Rise and Fall of The Low Energy Cut Off
	17 November 2008 by Ewan Dickson and Eduard Kontar
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? Read more

88	SEPs Link not Confirmed
	3 November 2008 by Gerry Share and Allan Tylka
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. Read more

87	The SphinX Instrument on CORONAS-PHOTON
	22 October 2008 by Janusz Sylwester and Ken Phillips
An exciting new instrument will begin observations at an exciting time. Read more

86	The Good Guys and the Rascals
	13 October 2008 by B. Dabrowski and Arnold Benz
Solar decimetric radio bursts - but only the good guys - correlate well with RHESSI hard X-rays. Read more

85	RHESSI Optical Images
	2008-09-29 by H. Jabran Zahid and Hugh Hudson
RHESSI makes optical images as well as X-ray and gamma-ray ones. This Nugget explains how. Read more

84	Flare Plasma Abundances - New X-ray Observations
	2008-09-15 by Brian Dennis and Richard Starr
MESSENGER is now exploring Mercury. It is also helping RHESSI to understand the solar X-ray spectrum and measure elemental abundances in flares. Read more

83	[[Hard X-rays from a Jet?]]
	2008-08-27 by Hazel Miller Bain and Lyndsay Fletcher
Observations during the rise phase of a M5.4 flare suggests that hard x-rays may be associated with a jet observed by TRACE. [[Hard X-rays from a Jet?|Read more]]

82	[[Are Stellar Flares like Solar Flares?]]
	2008-08-11 by Hugh Hudson and Beate Stelzer
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. [[Are Stellar Flares like Solar Flares?|Read more]]

81	[[The Microflare Height Distribution]]
	2008-07-28 by Steven Christe and Hugh Hudson
Another look at microflare positions... [[The Microflare Height Distribution|Read more]]

80	[[The McClymont Jerk]]
	2008-07-14 by Hugh Hudson and Brian Welsch
The sudden energy release of a flare in the solar atmosphere has many consequences. One of them may be the McClymont Jerk. [[The McClymont Jerk|Read more]]

For all previous Nuggets go to the old RHESSI Science Nugget Page.