They can be visible from Earth without the aid of a telescope.
Sunspots are dark spots visible on the sun that are caused by intense magnetic activity and causes the area where the sunspots are seen to cool the temperature at that area.
Sun spots are physical phenomenons produced by difference of tenperatures between various regions of the Sun surface.
We call them sunspots, but dark and cool are relative terms. A sunspot is dark only relative to the surrounding solar surface, but still intensely bright compared to your common household light bulb. It's cooler than the surrounding solar material, but still hot enough to vaporize a spaceship and anyone inside it in a fraction of a second.
Dark spots on the sun that are visible with the naked eye at sunrise/sunset are sunspots, which are cold areas caused by the sun's magnetic field.
Sun spots.
sun spots are cooler parts of the sun
the sun spots like black little spots on the sun that explode every 11 years
Saturn may or may not have Saturn spots. Only the sun has sun spots.
sun spots
The number of sunspots on the Sun varies over an 11-year solar cycle. During periods of high solar activity, there can be hundreds of sunspots visible on the Sun's surface. The next peak in sunspot activity is expected around 2025-2026.
Sun spots are not permanent, therefore it depends.
I believe that the layer in which sun spots occur would be the chromosphere. The chromosphere is the second layer in the sun's atmosphere and is about 2,000km above the photosphere(the first layer).