New to solar observing question. The prominence on the NE limb has been visible for days. I witnessed a huge outgassing a couple days ago. Does that mean it has been huge but mostly hidden by the limb?
Posted 11 January 2020 - 09:34 AM
I expect the answer is the rather useless: It could have been.
Prominence's seem to be gas, more correct plasma, held in a magnetic loop, so if the magnetic loop has existed for a few day then yes it will rotate into view.
It could as equally last shorter in time and so has appeared at a convenient time - hence the useless "could have been".
At either end should be a "sun spot" where the magnetic field(s) exit the sun, but visibility will depend on the temperature of the spot, not all have a great temperature difference, and for the distances involved the prominence needs to be big to get sufficence separation. Suppose the prominence itself could also mask/cover any sun spot from our view