Solar minimum Reference Libraries
Solar cycles: what are they and why should we care about them? Solar cycles are made up of what are known as solar minimums (min) and solar maximums (max). We refer to a solar min at the time when the sun is not active with many sunspots, while a solar max is just the opposite when we see a large increase in sunspot activity. So how long do solar cycles last? Typically they run on what is...
Sunspot -- A sunspot is a region on the Sun's surface (photosphere) that is marked by a lower temperature than its surroundings, and intense magnetic activity. Although they are blindingly bright, at temperatures of roughly 5000 Kelvin, the contrast with the surrounding material at some 6000 Kelvin leaves them clearly visible as dark spots. Interestingly, if they were isolated from the...
- A Roman unit of weight, 1⁄1728 of a pound.
- A weight of four grains used in weighing gold and precious stones; a carat.
- In anatomy, a formation suggesting a husk or pod.
- The lowest unit in the Roman coinage, the twenty-fourth part of a solidus.
- A coin of base silver of the Gothic and Lombard kings of Italy.