High Spatial Resolution Observations of a Sunspot with an ``Orphan Penumbra''
Abstract
We present a detailed analysis of a high spatial resolution, six hour time-series of a stable sunspot (NOAA 5612) obtained at the Big Bear Solar Observatory (BBSO) with the 65 cm vacuum reflector on August 2nd, 1989 (cf. H. Zirin and H. Wang: 1991, Adv. Space. Res., Vol. 11, pp. 225-231). The sunspot shows an ``orphan penumbra'' which exhibits motions similar to normal penumbrae. The time-series consists of filtergrams taken at Hα , CaK, and the continuum. In addition, magnetograms and dopplergrams were recorded with the BBSO Video Magnetograph System. Our investigation aims at a better understanding of moving magnetic features, penumbral fine-structures, and characteristics of the Evershed flow. Therefore, we derived and compared the proper motions visible in the different filtergrams, dopplergrams, and magnetograms.
- Publication:
-
AAS/Solar Physics Division Meeting #28
- Pub Date:
- May 1997
- Bibcode:
- 1997SPD....28.0245D