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Just trying to understand if these are the last of SC 23 or part of SC 24 and how do we tell?...And I thought the new cycle would have the spots at higher latitudes, or is that only later in the cycle?...

Thanx in advance!!!!!!!

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These three new groups are all Cycle 23 (old cycle) spots. They are of low solar latitude (7 to 10 degrees south) and are of the same polarity orientation as the old cycle spots ("black" polarity is leading in the southern hemisphere). The new cycle spots are appearing at higher solar latitudes (25 to 30 degrees north and south) and will have the "black" polarity leading in the northern hemisphere and the "white" polarity leading the groups in the southern hemisphere. Clear skies to you.

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David W. Knisely
Hyde Memorial Observatory
http://www.hydeobservatory.info
Prairie Astronomy Club
http://www.prairieastronomyclub.org

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David: It appears then that it is possible to have sunspots from both cycle 23 and 24 appearing at the same time, is that right? Is it normal to take a couple of months for a distinct changeover to occur?
How long would it take for the polarity of the sun to reverse? I gather it is not something that happens more or less instantly.
When we see the sunspots, do we have any idea just how deep inside the sun they originate? In other words, is this an action that starts very close to the surface, or does it start much closer to the centre?
Certainly learning lots about the sun this week!!
Keith

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Yes, sunspot cycles overlap to some degree, so we almost always see spots from both cycles present at least some of the time when the sun is near sunspot minimum. The typical overlap time period is around 18 months or so, but this varies somewhat. Sunspots exist in the uppermost regions of the solar photosphere, so they do not extend very deeply beneath the surface (typically, 2500 km or less). Clear skies to you.

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David W. Knisely
Hyde Memorial Observatory
http://www.hydeobservatory.info
Prairie Astronomy Club
http://www.prairieastronomyclub.org

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When looking at these pictures I am reminded of island chains. Is there a sub surface structure that is stationary and only breaks through the surface ocasionally as the surface rotates by? Sorry, but I know very little about astrophysics.

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Well, the structure below the surface that gives rise to an active region is a system of localized magnetic fields which are sometimes called a "flux tube". Each end of the tube where it breaks the surface marks one pole of a bipolar magnetic structure, although in some cases, there can be multiple flux tubes inside a single active region. The strong magnetic fields near the poles of the flux tubes inhibit the energy transfer from below, causing a cooling of the gas near the surface and thus creating the darkening that is seen in the sunspot itself. What exactly causes the creation of these flux tubes is not completely understood, but the older Babcock model of sunspot creation may be at least some factor in how they form. It involves the "wrapping up" of the overall solar magnetic field as the sun rotates differentially, creating the smaller-scale bipolar fields. Clear skies to you.

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David W. Knisely
Hyde Memorial Observatory
http://www.hydeobservatory.info
Prairie Astronomy Club
http://www.prairieastronomyclub.org

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>>>>Each end of the tube where it breaks the surface marks one pole of a bipolar magnetic structure,

Would we see this connection, if there was one between regions, in one of the EIT images?...If not, how can we tell?...

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Well, there may be some EIT images which show large arches that connect two ends of a flux tube well above the surface, but for what is going on *below*, there isn't much that can help. Looking at the H-alpha fibril structure around active regions can sometimes show a little of the "iron filings on paper with a bar magnet underneath" effect, as some of the fibrils and filaments tend to follow the magnetic field lines. However, as sunspot groups age, the spots tend to break their local connections with the other "pole" and form connections with other sometimes more distant fields of the opposite polarity. This can make it harder to see which spots are actually part of the same active region. Clear skies to you.

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David W. Knisely
Hyde Memorial Observatory
http://www.hydeobservatory.info
Prairie Astronomy Club
http://www.prairieastronomyclub.org

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