EDP Sciences
Free access
Volume 403, Number 2, May IV 2003
Page(s) L33 - L36
Section Letters
DOI http://dx.doi.org/10.1051/0004-6361:20030553

A&A 403, L33-L36 (2003)
DOI: 10.1051/0004-6361:20030553


Chromospheric polarity reversal on sunspots: New insight from spectro-polarimetric measurements

C. Briand1, 2 and A. Vecchio3

1  THEMIS, C/O IAC, via Lactea, 38200 La Laguna, Tenerife, Spain
2  LESIA, Observatoire de Meudon, 92195 Meudon Cedex principal, France
3  Dipartimento di Fisica - Ponte P. Bucci, Cubo 31C, Universitá della Calabria, 87036 Rende (CS), Italy

(Received 12 March 2003 / Accepted 13 April 2003)

We present here spectro-polarimetric observations of chromospheric and photospheric lines on an active region. We show that the presence of polarity reversal between photosphere and chromosphere cannot be detected relying on magnetograms and broad band and even narrow band filters only. We demonstrate that opposite signs in CaII magnetograms in sunspots compare to photospheric magnetograms are not due to a reversal of the magnetic field, but rather due to the presence of line core emission as suggested from theoretical arguments by Sánchez Almeida (1997).

Key words: Sun: magnetic field -- Sun: photosphere -- Sun: chromosphere

Offprint request: C. Briand, cbriand@themis.iac.es

© ESO 2003