Astronomy and Cosmology Spring2004 Quarter Project.
Sunspots and Solar Phenomena
Jake Sarrantonio, Eddie Janicki, John Samson, Jon Germano
A sunspot is an area seen as a dark spot, in contrast with its surroundings, on the photosphere of the Sun. Sunspots are
concentrations of magnetic flux, typically occurring in bipolar clusters or groups. They appear dark because they are cooler
than the surrounding photosphere. Larger and darker sunspots sometimes are surrounded (completely or partially) by penumbra
The dark centers are umbra.
Observations
•Sunspots appear as small dark areas on the
Sun’s brilliant surface.
Observations were originally done with the
Sunspotter, The Sunspotter is an amateur tool
that made accurate observations difficult. The
idea of the Sunspotter in practice is excellent
but due to the rotation of the Earth, the object
falls out of the field of view very quickly and
readjustment controls are non existent making it
necessary to manually move the whole unit to
keep the sun in the needed position to make
drawings from.
After two weeks of observation with the
Sunspotter, We received the solar filter we had
ordered. At that time, during early May, people
we’re purchasing solar filters in record numbers
to be prepared for the transit of Venus on June
8th. The solar filter fits on the end of the Meade
ETX 125ec telescope. We took pictures through
the telescope with a Minolta X-370 SLR
camera. We chose Ilford Delta 100 film for its
high resolution and low graininess.
The biggest difficulty was the weather leaving
gaps of days between sessions where usable
data was obtained.
•They were first recorded more than 2000
years ago by the Chinese.
•Because they are so large and prominent
Sunspots became a take off point for the
study of solar phenomena.
•Sunspots are observed to move across
the solar surface from East to West and
generally last from several hours to
several months
•Sunspots generally form in pairs with
one spot leading and the other following.
•Right now the number of Sunspots on
the sun is decreasing as we move
towards a sunspot minimum predicted to
be in the vicinity of 2007
The surface of the Sun is characterized by millions of
vertical cells, called granules, of gas rising and falling.
Hotter gas rises in the middle of the cells,while cooler
gases fall at the edges.
Granules pushed
onto their sides, the
penumbra.
Fig 1.5 Courtesy of
www.astronomy.gr
Umbra
Granules
Fig 1.7 Courtesy of Royal Swedish Academy of Sciences
http://www.solarphysics.kva.se/NatureNov2002/press_images_eng.html
Fig 1.6 Courtesy of Meade
Solar Flares
Effects of Sunspots on Earth
•The observed Sunspot cycle last 11
years corresponding to the Sun’s 22 year
magnetic cycle.
When the Sun is very active it generates a large number of
Sunspots, in turn causing a large amount of charged particles
between the Earth and itself. This effectively causes the
thickening of the Van Allen Belts, and as a result the lower
atmosphere is shielded from cosmic radiation, thus less
radioactivity occurs on Earth.
•As the cycle progresses towards the
Sunspot Maximum, Sunspots show up
closer and closer to the equator.
Conversely at times of low solar activity, when there are few if any
Sunspots, there fewer ions between the Earth and the Sun to shield
cosmic rays . Therefore, lower solar activity creates more
radioactivity on Earth.
•Sunspots cycles are best illustrated by
the “Butterfly Diagram.” As shown
below.
Fig. 1.2 &1.3 In these photographs, both the penumbra and
umbra are visible. Fig. 1.2 &1.3
Periods of high solar activity, large numbers of sunspots, correlate
exactly with the growth of powerful and sophisticated
civilizations. Low sunspot activity seems to be linked with Dark
Ages, which are marked by the general decline in the level of
cultural achievement that has also coincided with the fall of
civilizations.
A Solar Flare is a sudden release of energy and mass, created
by magnetic fields from Sunspots, twisting and braking.
Flares give off intense an amount of radiation in the covering
the spectrum from radio waves to X-rays.
X-class flares are big; they are major events that can trigger
planet-wide radio blackouts and long-lasting radiation storms.
M-class flares are medium-sized; they generally cause brief
radio blackouts that affect Earth's polar regions. Minor
radiation storms sometimes follow an M-class flare.
Compared to X- and M-class events, C-class flares are small
with few noticeable consequences here on Earth. Solar Flares
are best observed from orbital platforms that are not shielded
by the Earth’s atmosphere and can detect X-rays. From Earth
flares are observed by using a filter that isolates light from
Hydrogen Alpha as it is the best element to observe in the
visual spectrum for Sun Flares.
Acknowledgements
First and foremost:
Our Teacher, E.J. Zita, the CAL staff, and anyone else we forgot to mention
Images:
Our Data
1.1 taken from, http://spacescience.spaceref.com/ssl/pad/solar/images/bfly.gif
During the course of the project we accumulated 18 images of
the sun 5 photographs and thirteen drawings from the
Sunspotter. After unsuccessfully trying to calculate the
rotation of the sun do to missing data from poor weather, and
dealing with a 3 dimensional object with 2 dimensional
images. Preventing us from calculating rotation with any spots
near the edge, and the missing data made our calculations
worthless.
1.2&1.3 produced by our team.
1.4 taken from Mayan Prophecies Gilbert, Cotterell
1.5 taken from www.astronomy.gr
1.6 taken from www.meade.com
1.7 taken from Royal Swedish Academy of Sciences
http://www.solarphysics.kva.se/NatureNov2002/press_images_eng.html
Data:
Aveni, Anthony The Sky in Mayan Literature Oxford University Press 1992
Cotterell, Maurice Astrogenetics, Brooks Hill, 1988
Stix, Michael. The Sun: an Introduction. New York: Springer-Verlag. 1989
Kaufman, & Freedman. Universe sixth edition. New York: W.H. Freedman and
Company. 2002
Fig. 1.1 http://spacescience.spaceref.com/ssl/pad/solar/images/bfly.gif
Gribbin, John. Blinded by the Light. New York: 1991
Menzel, Donald Howard, Our Sun. Revised edition. Cambridge, Harvard University Press, 1959
Fig. 1.4 Mayan Prophecies Gilbert, Cotterell