pith. sign in

arxiv: 2604.23084 · v1 · pith:PAOJLW67new · submitted 2026-04-25 · 🌌 astro-ph.SR

Multi-Viewpoint Observation of a Failed Prominence Eruption on the Sun

Pith reviewed 2026-05-08 07:24 UTC · model grok-4.3

classification 🌌 astro-ph.SR
keywords failed solar eruptionsolar prominenceflux ropeexternal reconnectionmagnetic confinementmulti-viewpoint observationcoronal mass ejection
0
0 comments X

The pith

External reconnection on an erupting solar flux rope slows it down and prevents escape from the Sun.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper uses simultaneous off-limb and on-disk multi-viewpoint imaging to track a prominence eruption that begins but fails to leave the Sun. It identifies two reconnection sites: the usual flare reconnection behind the structure plus strong external reconnection directly on the flux rope, shown through multi-wavelength and spectroscopic signatures. The external process removes magnetic flux and reduces the rope's acceleration, allowing overlying fields to confine the structure. This supplies a concrete physical account of failed eruptions and why some solar-type stars show little coronal mass ejection activity.

Core claim

Multi-viewpoint observations establish that external reconnection on the erupting flux rope, distinct from standard flare reconnection, proceeds at a high rate, removes magnetic flux, and produces noticeable deceleration of the flux rope and embedded prominence, so that the eruption fails to reach the heliosphere under confinement by strong overlying magnetic fields.

What carries the argument

External reconnection on the erupting flux rope, which competes with standard flare reconnection by altering magnetic flux and dynamics.

Load-bearing premise

The observed multi-wavelength and spectroscopic signatures are produced by external reconnection on the erupting flux rope rather than by unrelated coronal processes.

What would settle it

Spectroscopic or imaging data showing no reconnection signatures at the locations expected on the flux rope, or no correlation between deceleration rate and external reconnection intensity.

read the original abstract

Solar eruptions are sudden ejections of coronal mass and magnetic fields accompanied by intense energy release. The eruptive structure does not always erupt successfully, but sometimes fails to escape the Sun after initiation. The failure of an eruption, however, provides an invaluable opportunity for understanding the intricate mechanism of eruptions. We present a comprehensive observation of a failed prominence eruption on the Sun, taking advantage of multi-viewpoint and multi-messenger imaging. Simultaneous off-limb and on-disk observation gives evidence of magnetic reconnection processes occurring at different sites during the flare. Particularly, in addition to the standard flare reconnection behind the eruption, strong external reconnection occurs on the erupting flux rope, evidenced by a wealth of signatures via multi-wavelength imaging and spectroscopy. The two reconnection processes may play contrasting roles in the flux rope's acceleration and compete in altering the magnetic flux in the rope. As the high rate of external reconnection proceeds, the flux rope and embedded prominence decelerate noticeably and fail to erupt into the heliosphere, under strong magnetic confinement of overlying fields. Our results illustrate a well-defined physical picture for solar eruptive activities and provide insight into the lack of coronal mass ejections found in other solar-type stars.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 2 minor

Summary. The paper reports multi-viewpoint, multi-wavelength observations of a failed solar prominence eruption. It identifies simultaneous signatures of standard flare reconnection behind the erupting structure and external reconnection occurring directly on the flux rope, and concludes that the high rate of the latter process causes the observed deceleration, preventing escape into the heliosphere under strong overlying magnetic confinement. The study uses off-limb and on-disk data to illustrate competing reconnection roles and offers implications for the scarcity of CMEs on other solar-type stars.

Significance. If the multi-viewpoint signatures unambiguously establish external reconnection as the dominant decelerating agent, the work supplies a concrete observational template for how external reconnection can suppress eruptions. The simultaneous imaging and spectroscopy from multiple vantage points is a clear strength for an observational solar-physics paper and could inform statistical studies of eruption success versus failure.

major comments (2)
  1. [Abstract and results on deceleration phase] The central claim that external reconnection proceeds at a sufficiently high rate to produce the observed deceleration (abstract; results section on flux-rope kinematics) is presented without any quantitative estimate of reconnection rate, reconnected flux, or Poynting-flux input. No integration of inflow velocities with local B-field strength, no comparison of energy or momentum budgets against standard flare reconnection, and no explicit test against simple magnetic-tension or projection-effect alternatives are provided, leaving the causal attribution qualitative.
  2. [Section describing multi-wavelength signatures] The attribution of specific brightenings, inflows, and spectroscopic flows to external reconnection on the erupting flux rope (rather than unrelated coronal reconnection or line-of-sight confusion) rests on multi-viewpoint morphology. However, the manuscript does not present a systematic exclusion of alternative interpretations, such as projection effects in the on-disk view or standard flare reconnection extending to the rope's leading edge; this weakens the uniqueness of the external-reconnection identification.
minor comments (2)
  1. Figure captions should explicitly label the observing instruments, wavelengths, and viewpoints for each panel to allow readers to trace the claimed spatial-temporal correlations without ambiguity.
  2. A short table summarizing the timing of key events (onset of standard reconnection, onset of external-reconnection signatures, start of deceleration) would improve readability.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for their constructive and detailed review. The comments have prompted us to strengthen the quantitative aspects of our analysis and to more explicitly address potential alternative interpretations. We have revised the manuscript accordingly.

read point-by-point responses
  1. Referee: [Abstract and results on deceleration phase] The central claim that external reconnection proceeds at a sufficiently high rate to produce the observed deceleration (abstract; results section on flux-rope kinematics) is presented without any quantitative estimate of reconnection rate, reconnected flux, or Poynting-flux input. No integration of inflow velocities with local B-field strength, no comparison of energy or momentum budgets against standard flare reconnection, and no explicit test against simple magnetic-tension or projection-effect alternatives are provided, leaving the causal attribution qualitative.

    Authors: We agree that the original manuscript presented the causal role of external reconnection largely through observational morphology and timing. In the revised version we have added quantitative estimates: reconnection rates are now calculated by combining measured inflow velocities from the multi-viewpoint EUV sequences with local magnetic-field strengths inferred from emission-measure analysis and standard coronal assumptions. We also include order-of-magnitude comparisons of the energy and momentum budgets between external reconnection and the standard flare reconnection, and we explicitly test against a pure magnetic-tension scenario by showing that the observed deceleration begins only after the external-reconnection signatures appear. These additions appear in the updated results section on flux-rope kinematics and in a new paragraph in the discussion. revision: yes

  2. Referee: [Section describing multi-wavelength signatures] The attribution of specific brightenings, inflows, and spectroscopic flows to external reconnection on the erupting flux rope (rather than unrelated coronal reconnection or line-of-sight confusion) rests on multi-viewpoint morphology. However, the manuscript does not present a systematic exclusion of alternative interpretations, such as projection effects in the on-disk view or standard flare reconnection extending to the rope's leading edge; this weakens the uniqueness of the external-reconnection identification.

    Authors: We have expanded the multi-wavelength signatures section with a dedicated subsection that systematically examines the main alternatives. Projection effects are ruled out by the three-dimensional reconstruction that places the brightenings and flows at the leading edge of the flux rope in both the on-disk and off-limb perspectives simultaneously. Standard flare reconnection is distinguished by its location beneath the rising structure, its higher-temperature X-ray signatures, and the absence of the observed Doppler flows on the rope itself. We also briefly consider unrelated coronal reconnection and show that its expected spatial and temporal characteristics do not match the data. These clarifications are now included in the revised text. revision: yes

Circularity Check

0 steps flagged

No circularity: pure observational report with no derivations or fitted parameters

full rationale

The paper is an observational study relying on multi-viewpoint imaging and spectroscopy to interpret signatures of external reconnection and its role in a failed eruption. No equations, derivations, parameter fitting, or quantitative models are presented; the central claim follows directly from data interpretation without reducing to self-defined inputs, fitted predictions, or self-citation chains. The analysis is self-contained against external benchmarks and contains no load-bearing steps that qualify as circular under the enumerated patterns.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

Observational study that applies standard solar-physics interpretations of EUV/X-ray signatures without introducing new parameters or entities.

axioms (1)
  • domain assumption Standard interpretation of EUV and X-ray imaging and spectroscopic signatures as indicators of magnetic reconnection in the solar corona.
    Invoked to link observed brightenings and flows to the two reconnection sites.

pith-pipeline@v0.9.0 · 5534 in / 1085 out tokens · 60135 ms · 2026-05-08T07:24:41.969783+00:00 · methodology

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Reference graph

Works this paper leans on

72 extracted references

  1. [1]

    Priest, E. R. & Forbes, T. G. The magnetic nature of solar flares.Astron. Astrophys. Rev.10, 313–377 (2002)

  2. [2]

    Chen, P. F. Coronal Mass Ejections: Models and Their Observational Basis.Living Rev. Sol. Phys.8, 1 (2011)

  3. [3]

    Webb, D. F. & Howard, T. A. Coronal Mass Ejections: Observations.Living Rev. Sol. Phys.9, 3 (2012)

  4. [4]

    S.et al.Impact of space weather on climate and habitability of terrestrial- type exoplanets.Int

    Airapetian, V. S.et al.Impact of space weather on climate and habitability of terrestrial- type exoplanets.Int. J. Astrobiol.19, 136–194 (2020)

  5. [5]

    Commun.7, 13001 (2016)

    Lugaz, N.et al.Earth’s magnetosphere and outer radiation belt under sub-Alfv´ enic solar wind.Nat. Commun.7, 13001 (2016)

  6. [6]

    Davenport, J. R. A. The Kepler Catalog of Stellar Flares.Astrophys. J.829, 23 (2016)

  7. [7]

    Vida, K.et al.The quest for stellar coronal mass ejections in late-type stars. I. Inves- tigating Balmer-line asymmetries of single stars in Virtual Observatory data.Astron. Astrophys.623, A49 (2019)

  8. [8]

    M.et al.Indications of stellar coronal mass ejections through coronal dimmings.Nat

    Veronig, A. M.et al.Indications of stellar coronal mass ejections through coronal dimmings.Nat. Astron.5, 697–706 (2021)

  9. [9]

    & Lammer, H

    Odert, P., Leitzinger, M., Hanslmeier, A. & Lammer, H. Stellar coronal mass ejections - I. Estimating occurrence frequencies and mass-loss rates.Mon. Not. R. Astron. Soc. 472, 876–890 (2017)

  10. [10]

    M., T¨ or¨ ok, T., Vrˇ snak, B., Manchester, W

    Green, L. M., T¨ or¨ ok, T., Vrˇ snak, B., Manchester, W. & Veronig, A. The Origin, Early Evolution and Predictability of Solar Eruptions.Space Sci. Rev.214, 46 (2018)

  11. [11]

    L., Sterling, A

    Moore, R. L., Sterling, A. C., Hudson, H. S. & Lemen, J. R. Onset of the Magnetic Explosion in Solar Flares and Coronal Mass Ejections.Astrophys. J.552, 833–848 (2001)

  12. [12]

    K., DeVore, C

    Antiochos, S. K., DeVore, C. R. & Klimchuk, J. A. A Model for Solar Coronal Mass Ejections.Astrophys. J.510, 485–493 (1999)

  13. [13]

    & Titov, V

    T¨ or¨ ok, T., Kliem, B. & Titov, V. S. Ideal kink instability of a magnetic loop equilibrium. Astron. Astrophys.413, L27–L30 (2004)

  14. [14]

    & Veronig, A

    Gou, T., Liu, R., Kliem, B., Wang, Y. & Veronig, A. M. The Birth of A Coronal Mass Ejection.Sci. Adv.5, 7004 (2019)

  15. [15]

    Magnetic flux ropes in the solar corona: structure and evolution toward eruption

    Liu, R. Magnetic flux ropes in the solar corona: structure and evolution toward eruption. Res. Astron. Astrophys.20, 165 (2020). 31

  16. [16]

    & Forbes, T

    Lin, J. & Forbes, T. G. Effects of reconnection on the coronal mass ejection process. J. Geophys. Res.105, 2375–2392 (2000)

  17. [17]

    Gou, T.et al.Solar Flare-CME Coupling throughout Two Acceleration Phases of a Fast CME.Astrophys. J. Lett.897, L36 (2020)

  18. [18]

    Bateman, G.MHD instabilities(1978)

  19. [19]

    & T¨ or¨ ok, T

    Kliem, B. & T¨ or¨ ok, T. Torus Instability.Phys. Rev. Lett.96, 255002 (2006)

  20. [20]

    A., Moore, R

    Falconer, D. A., Moore, R. L. & Gary, G. A. Correlation of the Coronal Mass Ejection Productivity of Solar Active Regions with Measures of Their Global Nonpotentiality from Vector Magnetograms: Baseline Results.Astrophys. J.569, 1016–1025 (2002)

  21. [21]

    & Zhang, J

    Wang, Y. & Zhang, J. A Comparative Study between Eruptive X-Class Flares Asso- ciated with Coronal Mass Ejections and Confined X-Class Flares.Astrophys. J.665, 1428–1438 (2007)

  22. [22]

    Sun, X.et al.Why Is the Great Solar Active Region 12192 Flare-rich but CME-poor? Astrophys. J. Lett.804, L28 (2015)

  23. [23]

    & Kliem, B

    T¨ or¨ ok, T. & Kliem, B. Confined and Ejective Eruptions of Kink-unstable Flux Ropes. Astrophys. J. Lett.630, L97–L100 (2005)

  24. [24]

    & Gibson, S

    Fan, Y. & Gibson, S. E. Onset of Coronal Mass Ejections Due to Loss of Confinement of Coronal Flux Ropes.Astrophys. J.668, 1232–1245 (2007)

  25. [25]

    J., Moon, Y

    Ji, H., Wang, H., Schmahl, E. J., Moon, Y. J. & Jiang, Y. Observations of the Failed Eruption of a Filament.Astrophys. J. Lett.595, L135–L138 (2003)

  26. [26]

    Liu, Y.et al.New Observation of Failed Filament Eruptions: The Influence of Asymmet- ric Coronal Background Fields on Solar Eruptions.Astrophys. J. Lett.696, L70–L73 (2009)

  27. [27]

    & Ding, M

    Chen, Y., Cheng, X., Chen, J., Dai, Y. & Ding, M. Observations of a Failed Solar Filament Eruption Involving External Reconnection.Astrophys. J.959, 67 (2023)

  28. [28]

    T., Kumar, P., Wyper, P

    Karpen, J. T., Kumar, P., Wyper, P. F., DeVore, C. R. & Antiochos, S. K. Solar Eruptions in Nested Magnetic Flux Systems.Astrophys. J.966, 27 (2024)

  29. [29]

    Gibson, S. E. & Fan, Y. Coronal prominence structure and dynamics: A magnetic flux rope interpretation.J. Geophys. Res.111, A12103 (2006)

  30. [30]

    & Ding, M.-D

    Zhang, J., Cheng, X. & Ding, M.-D. Observation of an evolving magnetic flux rope before and during a solar eruption.Nat. Commun.3, 747 (2012)

  31. [31]

    J., Antiochos, S

    Lynch, B. J., Antiochos, S. K., DeVore, C. R., Luhmann, J. G. & Zurbuchen, T. H. Topological Evolution of a Fast Magnetic Breakout CME in Three Dimensions.Astro- phys. J.683, 1192–1206 (2008). 32

  32. [32]

    & Magara, T

    Shibata, K. & Magara, T. Solar Flares: Magnetohydrodynamic Processes.Living Rev. Sol. Phys.8, 6 (2011)

  33. [33]

    T., Antiochos, S

    Karpen, J. T., Antiochos, S. K. & DeVore, C. R. The Mechanisms for the Onset and Explosive Eruption of Coronal Mass Ejections and Eruptive Flares.Astrophys. J.760, 81 (2012)

  34. [34]

    Petschek, H. E. Magnetic Field Annihilation. In Hess, W. N. (ed.)NASA Special Publication, vol. 50, 425 (1964)

  35. [35]

    J.622, 1251–1264 (2005)

    Lin, J.et al.Direct Observations of the Magnetic Reconnection Site of an Eruption on 2003 November 18.Astrophys. J.622, 1251–1264 (2005)

  36. [36]

    M., Dickson, E

    Gou, T., Veronig, A. M., Dickson, E. C., Hernandez-Perez, A. & Liu, R. Direct Obser- vation of Two-step Magnetic Reconnection in a Solar Flare.Astrophys. J. Lett.845, L1 (2017)

  37. [37]

    Processes and mechanisms governing the initiation and propagation of CMEs.Ann

    Vrˇ snak, B. Processes and mechanisms governing the initiation and propagation of CMEs.Ann. Geophys.26, 3089–3101 (2008)

  38. [38]

    P., Howard, R

    Zhang, J., Dere, K. P., Howard, R. A., Kundu, M. R. & White, S. M. On the Temporal Relationship between Coronal Mass Ejections and Flares.Astrophys. J.559, 452–462 (2001)

  39. [39]

    M., Kontar, E

    Temmer, M., Veronig, A. M., Kontar, E. P., Krucker, S. & Vrˇ snak, B. Combined STEREO/RHESSI Study of Coronal Mass Ejection Acceleration and Particle Acceler- ation in Solar Flares.Astrophys. J.712, 1410–1420 (2010)

  40. [40]

    & Dud´ ık, J

    Aulanier, G. & Dud´ ık, J. Drifting of the line-tied footpoints of CME flux-ropes.Astron. Astrophys.621, A72 (2019)

  41. [41]

    Jiang, C.et al.A model of failed solar eruption initiated and destructed by magnetic reconnection.Mon. Not. R. Astron. Soc.525, 5857–5867 (2023)

  42. [42]

    Astron.7, 815–824 (2023)

    Gou, T.et al.Complete replacement of magnetic flux in a flux rope during a coronal mass ejection.Nat. Astron.7, 815–824 (2023)

  43. [43]

    Ruffenach, A.et al.Multispacecraft observation of magnetic cloud erosion by magnetic reconnection during propagation.J. Geophys. Res.117, A09101 (2012)

  44. [44]

    & Liu, R

    Luo, R. & Liu, R. Where and How Does a Decay-index Profile Become Saddle-like? Astrophys. J.929, 2 (2022)

  45. [45]

    DeVore, C. R. & Antiochos, S. K. Homologous Confined Filament Eruptions via Mag- netic Breakout.Astrophys. J.680, 740–756 (2008)

  46. [46]

    C., Priest, E

    Demoulin, P., Henoux, J. C., Priest, E. R. & Mandrini, C. H. Quasi-Separatrix layers in solar flares. I. Method.Astron. Astrophys.308, 643–655 (1996). 33

  47. [47]

    & Howard, R

    Yashiro, S., Akiyama, S., Gopalswamy, N. & Howard, R. A. Different Power-Law Indices in the Frequency Distributions of Flares with and without Coronal Mass Ejections. Astrophys. J. Lett.650, L143–L146 (2006)

  48. [48]

    J.900, 128 (2020)

    Li, T.et al.Magnetic Flux of Active Regions Determining the Eruptive Character of Large Solar Flares.Astrophys. J.900, 128 (2020)

  49. [49]

    Donati, J. F. & Landstreet, J. D. Magnetic Fields of Nondegenerate Stars.Annu. Rev. Astron. Astrophys.47, 333–370 (2009)

  50. [50]

    D., Drake, J

    Alvarado-G´ omez, J. D., Drake, J. J., Cohen, O., Moschou, S. P. & Garraffo, C. Suppres- sion of Coronal Mass Ejections in Active Stars by an Overlying Large-scale Magnetic Field: A Numerical Study.Astrophys. J.862, 93 (2018)

  51. [51]

    R.et al.The Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory (SDO).Sol

    Lemen, J. R.et al.The Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory (SDO).Sol. Phys.275, 17–40 (2012)

  52. [52]

    D., Thompson, B

    Pesnell, W. D., Thompson, B. J. & Chamberlin, P. C. The Solar Dynamics Observatory (SDO).Sol. Phys.275, 3–15 (2012)

  53. [53]

    Cheung, M. C. M.et al.Thermal Diagnostics with the Atmospheric Imaging Assem- bly on board the Solar Dynamics Observatory: A Validated Method for Differential Emission Measure Inversions.Astrophys. J.807, 143 (2015)

  54. [54]

    Phys.243, 63–86 (2007)

    Golub, L.et al.The X-Ray Telescope (XRT) for the Hinode Mission.Sol. Phys.243, 63–86 (2007)

  55. [55]

    Science overview.Astron

    M¨ uller, D.et al.The Solar Orbiter mission. Science overview.Astron. Astrophys.642, A1 (2020)

  56. [56]

    Rochus, P.et al.The Solar Orbiter EUI instrument: The Extreme Ultraviolet Imager. Astron. Astrophys.642, A8 (2020)

  57. [57]

    M.et al.Coronal dimmings and what they tell us about solar and stellar coronal mass ejections.Living Rev

    Veronig, A. M.et al.Coronal dimmings and what they tell us about solar and stellar coronal mass ejections.Living Rev. Sol. Phys.22, 2 (2025)

  58. [58]

    E.et al.The Large Angle Spectroscopic Coronagraph (LASCO).Sol

    Brueckner, G. E.et al.The Large Angle Spectroscopic Coronagraph (LASCO).Sol. Phys.162, 357–402 (1995)

  59. [59]

    Cargill, P. J. On the Aerodynamic Drag Force Acting on Interplanetary Coronal Mass Ejections.Sol. Phys.221, 135–149 (2004)

  60. [60]

    &ˇZic, T

    Vrˇ snak, B. &ˇZic, T. Transit times of interplanetary coronal mass ejections and the solar wind speed.Astron. Astrophys.472, 937–943 (2007)

  61. [61]

    Large-scale Globally Propagating Coronal Waves.Living Rev

    Warmuth, A. Large-scale Globally Propagating Coronal Waves.Living Rev. Sol. Phys. 12, 3 (2015)

  62. [62]

    Howard, T. A. & Pizzo, V. J. Challenging Some Contemporary Views of Coronal Mass Ejections. I. The Case for Blast Waves.Astrophys. J.824, 92 (2016). 34

  63. [63]

    E., Pomoell, J., Kumari, A., Kilpua, E

    Morosan, D. E., Pomoell, J., Kumari, A., Kilpua, E. K. J. & Vainio, R. A type II solar radio burst without a coronal mass ejection.Astron. Astrophys.675, A98 (2023)

  64. [64]

    L.et al.The EUV Imaging Spectrometer for Hinode.Sol

    Culhane, J. L.et al.The EUV Imaging Spectrometer for Hinode.Sol. Phys.243, 19–61 (2007)

  65. [65]

    De Pontieu, B.et al.The Interface Region Imaging Spectrograph (IRIS).Sol. Phys. 289, 2733–2779 (2014)

  66. [66]

    Astrophys.642, A15 (2020)

    Krucker, S.et al.The Spectrometer/Telescope for Imaging X-rays (STIX).Astron. Astrophys.642, A15 (2020)

  67. [67]

    Phys.298, 114 (2023)

    Massa, P.et al.The STIX Imaging Concept.Sol. Phys.298, 114 (2023)

  68. [68]

    E.et al.Microwave and Hard X-Ray Observations of the 2017 September 10 Solar Limb Flare.Astrophys

    Gary, D. E.et al.Microwave and Hard X-Ray Observations of the 2017 September 10 Solar Limb Flare.Astrophys. J.863, 83 (2018)

  69. [69]

    H.et al.The Helioseismic and Magnetic Imager (HMI) Investigation for the Solar Dynamics Observatory (SDO).Sol

    Scherrer, P. H.et al.The Helioseismic and Magnetic Imager (HMI) Investigation for the Solar Dynamics Observatory (SDO).Sol. Phys.275, 207–227 (2012)

  70. [70]

    K.et al.The Polarimetric and Helioseismic Imager on Solar Orbiter.Astron

    Solanki, S. K.et al.The Polarimetric and Helioseismic Imager on Solar Orbiter.Astron. Astrophys.642, A11 (2020)

  71. [71]

    Alissandrakis, C. E. On the computation of constant alpha force-free magnetic field. Astron. Astrophys.100, 197–200 (1981)

  72. [72]

    In Fineschi, S

    Wuelser, J.-P.et al.EUVI: the STEREO-SECCHI extreme ultraviolet imager. In Fineschi, S. & Gummin, M. A. (eds.)Telescopes and Instrumentation for Solar Astro- physics, vol. 5171 ofSociety of Photo-Optical Instrumentation Engineers (SPIE) Con- ference Series, 111–122 (2004). 35