Visible and near-infrared contrast of faculae in active region NOAA 8518

Document Type

Article

Publication Date

10-1-2004

Abstract

We compare the contrast of faculae, in visible light and in the near infrared (NIR), that were associated with the active region NOAA 8518 which crossed the solar disk from April 19 to 27, 1999. We obtained NIR continuum images at 1.6μm at the Big Bear Solar Observatory (BBSO) with an Indium Gallium Arsenide (InGaAs) NIR digital camera. We also obtained high-resolution longitudinal mag-netograms and visible light filtergrams at 610.3 nm with the newly developed Digital Vector Magnetograph (DVMG). Our data show that the contrast of faculae has the same sign in both the visible and the NIR. We did not find any so-called "dark faculae", faculae that are bright in the visible and simultaneously dark in the NIR. We determined a threshold magnetic flux density that separates pores from faculae.

Identifier

84999086319 (Scopus)

Publication Title

Chinese Journal of Astronomy and Astrophysics

External Full Text Location

https://doi.org/10.1088/1009-9271/4/5/481

ISSN

10099271

First Page

481

Last Page

489

Issue

5

Volume

4

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