View Full Version : A Magnetically Backwards Sunspot

2006-Aug-16, 05:01 PM
Astronomers have been waiting to see a very special kind of sunspot, and this week, they saw what they were hoping for: it was backward. It only lasted a few hours, but it reveals that the Sun's next solar cycle could be getting underway. As the Sun moves through its 11-year cycle of solar maximum and minimums, the magnetic orientation of its sunspots reverses. Solar astronomers think that the upcoming Cycle 24 should be one of the stormiest in decades, producing many sunspots and powerful solar storms. The auroras should be beautiful.

Read the full blog entry (http://www.universetoday.com/2006/08/16/a-magnetically-backwards-sunspot/)

2006-Aug-17, 02:19 PM
"On July 31st, a tiny sunspot was born. It popped up from the sun’s interior, floated around a bit, and vanished again in a few hours. On the sun this sort of thing happens all the time and, ordinarily, it wouldn’t be worth mentioning. But this sunspot was special: It was backward."

hey i was just wondering what it means by how the sunspot was backwards? how can it be backwards? can someone please explain that to me? thanks

2006-Aug-17, 04:47 PM
I posted comments on this topic on my website on 31 July and an update on 04 August. See http://members.chello.be/j.janssens/Engwelcome.html

This group was not numbered by NOAA, and after verification with SIDC, it appears only very few observers saw this spot (despite its visibility for about 10 hours). Thus, it will probably not show up in the official daily Wolfnumbers.

We are in the same situation as at the beginning of SC23 over 11 years ago, when a (numbered) spotgroup appeared also at 13 degrees latitude. You can't be sure if these are new or old cycle groups. However, the appearance of this group did satisfy the "rule" that groups of a new cycle appear between 12 and 20 months prior to cycle minimum. It's interesting to note that the first real new cycle region (this is: at high solar latitude) appeared at the very month of solar cycle minimum (May 96), still at a modest 25 degrees. Until then, not a single "SC23"-group had latitudes in excess of 20 degrees!

It was not until early 1997 before SC23-groups outnumbered SC22-groups, and the latter remained visible till 1998. See graphic of 04 August.

One more thing: A new solar cycle starts when the smoothed monthly Wolfnumber reaches its minimum (at least: that's the definition). Other parameters like the number of flares or the radio-flux may reach their respective minima several months earlier or later. See http://members.chello.be/j.janssens/SC23web/SCweb2.pdf