Sun questions

[markus.a.bergh]

Dear Friends,

Please help me with the following questions:

How often does the sun rotate (sorry if the lingo is incorrect)?

How often can sunspots be seen (using a solar telescope for example)?

How long are sunspots visible for?

Have a nice day, Markus.

[renormalised (Carl)]

Well, at its equator the Sun rotates in roughly 25 days and at the poles 32 days or thereabouts.

Sunspots cycle over a roughly 11.2 year period and their occurrence over that time depends on how active (or not) the Sun is at the time.

You can see them whenever they're visible on the Sun's surface, some last days others for months.

[markus.a.bergh]

Wow. 11 year. So why would anyone want to buy a small solar telescope if you have to wait that long to see anything ! (other than looking for transits every x years etc).

[renormalised (Carl)]

Originally Posted by markus.a.bergh

Wow. 11 year. So why would anyone want to buy a small solar telescope if you have to wait that long to see anything ! (other than looking for transits every x years etc).

There's more to look at than just sunspots. There's solar granulation, prominences, flares, plages, spicules etc etc. The solar minimum usually only lasts a year or so before the cycle starts to climb back up again. You never know what the Sun is going to do, so it's good to keep an eye on it.

[casstony]

It's handy to have a white light solar filter ready to watch sunspots when they do occur - baader solar film filters can be purchased for around $40 and a cheap refractor will suffice.