Near-infrared observations at 1.56 microns of the 2003 october 29 X10 white-light flare

Yan Xu, Wenda Cao, Chang Liu, Guo Yang, Jiong Qiu, Ju Jing, Carsten Denker, Haimin Wang

Research output: Contribution to journalArticlepeer-review

65 Scopus citations

Abstract

We present high-resolution observations of an X10 white-light flare in solar NOAA Active Region 10486 obtained with the Dunn Solar Telescope (DST) at the National Solar Observatory/Sacramento Peak on 2003 October 29. Our investigation focuses on flare dynamics observed in the near-infrared (NIR) continuum at 1.56 μm. This is the first report of a white-light flare observed at the opacity minimum. The spatial resolution was close to the diffraction limit of the 76 cm aperture DST. The data benefited from a newly developed high-order adaptive optics system and a state-of-the-art NIR complex metal oxide semiconductor focal plane array. In addition, we compared hard X-ray (HXR) data of RHESSI and magnetograms of the Michelson Doppler Imager on board SOHO with the NIR continuum images. Although it is still possible that some high-energy electrons penetrate deep to this layer, a more likely explanation of the observed emission is back-warming. During the impulsive phase of the flare, two major flare ribbons moved apart, which were both temporally and spatially correlated with RHESSI HXR ribbons. The maximum intensity enhancement of the two flare ribbons is 18% and 25%, respectively, compared to the quiet-Sun NIR continuum. The separation speed of the ribbons is about 38 km s-1 in regions with weak magnetic fields and decreases to about 19 km s-1, where stronger magnetic fields are encountered. The derived electric field in reconnection current sheet Ec is of the order of 45 V cm-1 during the flare maximum.

Original languageEnglish (US)
Pages (from-to)L131-L134
JournalAstrophysical Journal
Volume607
Issue number2 II
DOIs
StatePublished - Jun 1 2004

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Keywords

  • Sun: activity
  • Sun: flares
  • Sun: infrared
  • Sun: photosphere

Fingerprint

Dive into the research topics of 'Near-infrared observations at 1.56 microns of the 2003 october 29 X10 white-light flare'. Together they form a unique fingerprint.

Cite this