Motions around a decaying sunspot

✍ Scribed by R. Muller; B. Mena

• Publisher: Springer
• Year: 1987
• Tongue: English
• Weight: 881 KB
• Volume: 112
• Category: Article
• ISSN: 0038-0938
• DOI: 10.1007/bf00148783

✦ Synopsis

We have measured the motion of facular points and granules in the same region near a decaying sunspot. It is found that both features move away across the moat surrounding the sunspot. The mean speed of facular points is larger than that of granules: 0.65 km s -~ and 0.4 km s -1, respectively. These results are consistent with previous measurements of the speed of bright network features and moving magnetic fields, as well as of non-magnetic photospherical material. They support models in which a decaying sunspot is at the center of a supergranule, whose horizontal motions sweep out granules and magnetic flux tubes associated to the facular points. It is also found that granules are dragged by supergranular motions away of the moat. * Contributions from the Kwasan and Hida Observatories, University of Kyoto. ** A part of this Work was done while one of the authors (R.M.) was staying at the Kwasan and Hida Observatories, University of Kyoto, Japan, as a JSPS research fellow.