Analogy between Sunspots 1158,1164,1166 on the Sun
- A.Deoras
I- Introduction
This article describes the phases of sunspots 1158,1164,1166 on the sun during a period of Feb-Mar 2011. This article tries to establish a relation between the mentioned sunspots ( Magnetic Field Relation) which powered X class flares from region 1158,1166 during the Solar Cycle 24
II- What are Sunspots?
Sunspots are the temporary features on the photosphere of the sun which are formed due to inhibits convection making them to appear dark due to reduced temperature as compared to other regions of sun
III- Magnetic Classification of Sunspots i.e Classification of Sunspots on the nature of magnetic fields around them
Sunspots are classified on the basis of Magnetic field around them i.e on the basis of magnetic poles,their complexity(intensity).
Mount Wilson Sunspot Magnetic Classification
Classification of the magnetic character of sunspots according to rules set forth by the Mount Wilson Observatory in California.
alpha: A unipolar sunspot group.
beta: A sunspot group having both positive and negative magnetic polarities (bipolar), with a simple and distinct division between the polarities.
gamma: A complex active region in which the positive and negative polarities are so irregularly distributed as to prevent classification as a bipolar group.
beta-gamma: A sunspot group that is bipolar but which is sufficiently complex that no single, continuous line can be drawn between spots of opposite polarities.
delta: A qualifier to magnetic classes(see below) indicating that umbrae separated by less than 2 degrees within one penumbra have opposite polarity.
beta-delta: A sunspot group of general beta magnetic classification but containing one (or more) delta spot(s).
beta-gamma-delta: A sunspot group of beta-gamma magnetic classification but containing one (or more) delta spot(s).
gamma-delta: A sunspot group of gamma magnetic classification but containing one (or more) delta spot(s).
II. SUNSPOT 1158-
First appeared - 7th Feb 2011 as an area ( AR 1158)
Disappeared/Rotated Away - Rotated away on 21st Feb 2011
First Significant Flare produced- M6.6 on 13th Feb 2011
Max Flare produced- X2.2 ( First X class flare of Solar Cycle 24)
Date- 15th Feb 2011 at 0156UT
AR 1158 Magnetic Field starts becoming more complex after the formation.
As a result, a marked sunspot 1158 appears on the sun on 11th Feb 2011.
Status as of 11-12th Feb 2011
Sunspot 1158's Magnetograms clearly indicate strengthening of polarity i.e the black and white patches ( South and North pole) respectively becomes wide and complex
The Magnetic classification now reaches a Gamma Magnetic Field which produces C class flares to low M class flares.
13th Feb 2011-
An M6.6 Solar Flare was produced from this sunspot.
Magnetic Classification on 13th Feb- Beta-Gamma magnetic field.
Earth Directed flare caused a R2 Radio Blackout.
Sunspot Widened more than 100,000 kms as seen here
Below are the Magnetogram Images of 12th Feb and 13th Feb of nearly the same time i.e 1753UT.
First Image is of 12th Feb showing Gamma Magnetic field
Second Image is of 13th Feb showing Beta-Gamma Magnetic field.
Note- The polarity of Sunspot 1158 strengthened as seen from widening of black and white patches ( South and North Pole respectively) in a period of 24hrs.
14TH Feb 2011-
Sunspot continued to become more complex due to differential rotation speeds at different latitudes on the sun.
Magnetic field- Beta Gamma Delta.
Above- The 14th Feb Magnetogram of the region encircled in green showing more complex polarity and classification into Beta-Gamma-Delta spot.
15th Feb 2011-
On early morning hours (0156UT), An X2.2 solar flare was released from the sunspot.
The sunspot continued to have a Beta-Gamma-Delta field. But the question arises what made this Sunspot to hurl an X2.2 Solar Flare.
Explanation using a new product view which show something very common with sunspots.
THE MAGNETIC FIELD LINES
AS SEEN FROM THE ABOVE 2048PFSS PLOT, THE SUNSPOT 1158 AS SEEN IN THE LOWER RIGHT OF THE IMAGE HAS SOME SYMMETRICAL MAGNETIC FIELD LINES. MAGNETIC LINES ( ASSUMED ) TO START FROM NORTH POLE( WHITE) REACHING TO BLACK(SOUTH POLE) CONSTITUTING A MAGNETIC DIPOLE.
DESPITE OF THE COMPLEXITY IN POLARITY AS SHOWN BY THE MAGNETOGRAM, THIS IMAGE SHOWS THAT THE MAGNETIC LINES AROUND THE SUNSPOT ARE SYMMETRICAL AND HAVE AN OPEN FIELD STRUCTURE.
III. Sunspot 1166
First Appeared- ( On the earth side of Sun ) on 3rd March 2011
Sunspot had formed on the side of the sun away from the earth.
Disappeared/Rotated away - Presently on the Earth side of Sun
First noted Solar flare- M2 class flare at 1400UT at 7th March 2011.
Max Solar Flare- X1.5 flare
AT- 2323UT on 9th March 2011.
Magnetogram of region 1166 showing a complex bipolar sunspot or Gamma Magnetic field.
6TH MARCH AND 7TH MARCH 2011
Sunspot 1166 continued to evolve and having beta-gamma classification.
Size of Sunspot highly increases.
BELOW-
MAGNETOGRAM IMAGES OF SUNSPOT 1166.
TOP IMAGE IS OF 6TH MARCH SHOWING THE REGION AS SEEN IN THE TOP LEFT OF THE SUN.
SECOND IMAGE IS OF THE MAGNETIC FIELD LINES ON 7TH MARCH 2011.
AS MENTIONED ABOVE, SUNSPOT 1166 PRODUCED AN M CLASS FLARE ON 7TH MARCH.
IT CAN BE NOTICED THAT THE POLARITY IS COMPLEX WITH SYMMETRIC ARRANGEMENT OF MAGNETIC FIELD LINES
*** SAME AS SEEN IN THE CASE OF SUNSPOT 1158 WHICH ALSO HAS OPEN MAGNETIC STRUCTURE
X 1.5 Class flare-
Sunspot 1166 produced an X 1.5 class flare as described here
IV. Sunspot 1164-
First appeared ( On the Earth side of the sun) - 25th Feb 2011
Sunspot had formed on the side of sun away from earth
Disappeared/Rotated away - Rotated away on 10th Mar 2011
First noted Solar flare- 24th Feb 2011 ..M3 Class flare
Max Solar Flare- M1 solar flare at 1431UT on 7th March 2011.
SUNSPOT REGION 1163-1164 FIRST APPEARED ON 25TH FEB 2011.
SUNSPOT DEVELOPED ON THE SIDE OF SUN AWAY FROM THE EARTH.
ON 25TH FEB 2011 THE SUNSPOT HAD "BETA-GAMMA MAGNETIC FIELD"
It was noted that despite having Beta-Gamma magnetic field in the initial period and then a Delta Magnetic classification, sunspot 1164 didn't produce any strong flare other than M1 flare.
Low C class flares were produced by the sunspot during the period of appearance.
MAGNETIC FIELD LINES OF 1164
AS SEEN FROM THE PICTURE ABOVE OF THE MAGNETOGRAM OF 7TH MARCH 2011, THE DELTA SUNSPOT HAS TREMENDOUS COMPLEX POLARITY AND EVEN TWISTED MAGNETIC FIELD LINES.
MAGNETIC FIELD LINES WERE TWISTED IN THE REGION 1164.
*** ALSO SEEN IN THE IMAGE, SUNSPOT 1166 AT THE UPPER LEFT OF THE SUN.
COMPARE THE MAGNETIC FIELD LINES OF THE SUNSPOT 1164 AND 1166!
IV - GENERAL OBSERVATIONS OF THE ACTIVITIES OF SUNSPOTS 1158,1164,1166
1] Sunspot 1158 and 1166 produced an X class flare along with multiple M and C class flares
2] Sunspot 1164 produced NO big flare other than a M1 class flare
3] The overall structure of Magnetic Field lines of Sunspot 1158 and 1166 were identical to each other while the structure of magnetic field lines of sunspot 1164 differed.
4] Sunspot 1158 and 1166 had open magnetic field structure while there was complex magnetic field lines in the region 1164.
V- GRAPHICAL DISPLAY OF MAGNETIC FIELD LINES OF SUNSPOT 1158,1164
- DISPLAY OF SYMMETRIC MAGNETIC FIELD LINES.
THE COMPARISON OF IMAGES OF SUNSPOT 1166,1158 AND 1169 SHOW SYMMETRICAL CORONAL LOOPS.
EXAMPLES BELOW
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VI. EFFECT OF SYMMETRIC CORONAL LOOPS ON VARIOUS REGIONS OF THE SUN ( Open Flux Tube modification proposal)
As seen from the above few images of the magnetic field around sunspot 1158,1166 we can clearly see that magnetic field lines are symmetrical from one pole to another pole i.e there is no complexity in field line symmetry. Due to such orderly arrangement, there is an area having Coronal loop directly reaching to the transition region of the sun. These coronal loops also have symmetrical arrangement.
From the Photosphere of the sun the coronal loops originate having an extent till the Sun's corona. It can also be said that there is some passage which connects the Sun's interior to the Corona which acts as a gateway to Coronal Mass Ejections.
Due to Symmetry of Coronal loops outside the photosphere, it can be inferred that the symmetry is maintained in the interior part of the sun.
Thus due to supposed orderly arrangement of these coronal loops, there is symmetric magnetic field line arrangement from one polarity to another polarity which enhances energy transfer through transition region and corona.
*** Open Flux tube
Open Flux tube is that passage passing from Sun's interior to Sun's Corona. They are surrounded by the coronal loops.
VII- ELASTIC BAND EXAMPLE AND CONCLUSION
The symmetry of the magnetic field lines can be compared to an elastic band.
Consider an elastic band of any mass,volume.
The elastic band is at rest position with no potential energy stored in it as seen from the below figure top portion ( Untwisted Elastic Band).
On Winding the Elastic band,potential energy of user is stored in it and band takes the form of a twisted band as seen in the lower picture.
After the user removes the hand, Potential Energy gets converted into unwinding energy which again brings back the elastic band in original form as of the top image.
During Winding,after a certain limit ( number of Rotations of the elastic band about the thumb axis of user were the band is held), user can't wind the elastic band. On releasing, band starts unwinding rapidly ( Energy conversion and release)
Thus that becomes the maximum energy limit that can be stored. If user doesn't wind till that Max limit, then on unwinding, weak energy release is obtained.
* Similarly, magnetic field of a sunspot starts winding up due to differential rotation speed at different latitude of the sun. The required energy is stored in the coronal loops.
Some sunspot region reach the maximum limit where they become more symmetrical or maximum wound ( Sunspot 1169,1158,1166) while some don't reach till that max limit ( Sunspot 1164) which restricts Intensity of Solar Flare
BASIC CONCLUSIONS-
1] MAGNETIC FIELD OF EVERY SUNSPOT BECOMES COMPLEX BUT WINDING ABOUT A PERPENDICULAR AXIS PASSING THROUGH THE GEOMETRICAL CENTER OF PERPENDICULAR DISTANCE BETWEEN REGIONS OF OPPOSITE POLARITY
2] SOME SUNSPOTS WHICH ARE CAPABLE OF PRODUCING X CLASS FLARES HAVE GONE THROUGH MAXIMUM WINDING.
3] SOME SUNSPOTS DON'T REACH TO THE MAXIMA AND SO PRODUCE ONLY LOW CLASS FLARES
4] THE MORE SYMMETRICAL MAGNETIC FIELD( DEGREE OF CLOSENESS OF FIELD LINES) THE MORE HIGH CLASS FLARES AND CORONAL MASS EJECTION THE SUNSPOT CAN TRIGGER.
VIII- References
3] Spaceweather.com for providing database on sunspots,solar flare activities and simplified magnetic classification rules
4] Mount Wilson Observatory for providing the rules of Magnetic Classification of Sunspots.
