A solar X-ray Bright point (BP) was observed with the SUMER-spectrograph of the SOHO-observatory. The data consist of four far-UV spectral lines formed between 2 10^4 - 6 10^5 K, with 2 arcsec spatial, 2.8 min temporal and 4 km/s spectral resolution. A striking feature is the strong microflaring and appearance of several short lived transients. Using simultaneous magnetic field measurements the region observed seemed to lie above a cancelling flux region. With respect to the filling factor and emission measure this particular BP was similar to the average surface of a moderately active solar type star.
@article{arxiv.astro-ph/0207274,
title = {Microflaring of a solar Bright point},
author = {O. Vilhu and J. Huovelin and S. Pohjolainen and J. Virtanen and W. Curdt},
journal= {arXiv preprint arXiv:astro-ph/0207274},
year = {2009}
}
Comments
7 pages, 6 figures, in press Astronomy and Astrophysics; for Fig.3 it is recommended to download separately the colour version h3653f3.pdf