𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Oscillatory behaviour in sunspot umbrae

✍ Scribed by M. A. Aballe Villero; J. I. García Rosa; E. Marco; M. Vázquez


Publisher
Springer Netherlands
Year
1990
Tongue
English
Weight
285 KB
Volume
170
Category
Article
ISSN
0004-640X

No coin nor oath required. For personal study only.


📜 SIMILAR VOLUMES


Hα oscillations in sunspot umbrae
✍ Gary L. Phillis 📂 Article 📅 1975 🏛 Springer 🌐 English ⚖ 689 KB

Direct measurement of intensity and photographic subtractions of simultaneous Doppler filtergrams at Hc~zk0.3 ,~ in a time-lapse sequence of McMath 11482 has shown velocity oscillations in sunspot umbrae. These oscillations exhibit the following characteristics: (a) A characteristic oscillation freq

The Mgiih line in sunspot umbrae
✍ J. B. Gurman 📂 Article 📅 1984 🏛 Springer 🌐 English ⚖ 152 KB

Observations of the MglI h line in the umbrae of five sunspots show a spread of a factor of 3 in peak intensity. This range is larger than, and brackets, the range found in a single umbra by Lites and Skumanich (1982).

Waves in the sunspot umbra
✍ H. M. Antia; S. M. Chitre 📂 Article 📅 1979 🏛 Springer 🌐 English ⚖ 589 KB

The magnetoacoustic modes excited in a thermally conducting polytropic fluid layer in the presence of a vertical magnetic field are examined with a view to classify them with the help of phase diagrams. The possibility of identifying the umbral flashes with overstable magnetoacoustic modes is explor

Oscillatory motions in sunspots
✍ J. M. Beckers; R. B. Schultz 📂 Article 📅 1972 🏛 Springer 🌐 English ⚖ 601 KB

We observe vertical velocity oscillations in some sunspot umbrae with periods of about 180 s and peak to peak amplitudes up to 1 km s -1. These oscillations are not visible in either the line depth, line width or the continuum intensity. No correlation seems to exist between the occurence of these o