Download Slide 1

Journal 11/15/16
Why might we care if the sun’s surface is getting a little
more violent?
Objective
Tonight’s Homework
To learn about activity on the
surface of the sun
Read 16.1 and 16.4 (pp 386 387, 396 - 401)
Sunspots
Like many planets, the sun has a magnetic
field (from metallic hydrogen).
Unlike the planets, though, the sun’s
magnetic field doesn’t have just one north
and south pole, but millions.
This
extremely
complex
field has
several
results.
Sunspots
The visible evidence of the sun’s magnetic
field are the sunspots. These spots are
roughly the size of the Earth and are
indications of places where the magnetic field
has become
twisted.
Their appearance
comes from the
fact that they
are about 1,000
K cooler than
the regions of
the sun around
them.
Sunspots
Sunspots form as the sun’s magnetic field
becomes twisted, as illustrated in this picture.
Sunspots
Sunspots
Sunspots are noted for appearing in certain
latitudes as well. The more sunspots visible on
the sun, the more positive and negative the
latitudes will be. At their most extreme,
sunspots will reach as far as 60 N or 60 S, but
never farther.
Sunspots
So why do we care about sunspots?
They indicate more violent activity on the sun.
The more sunspots the sun has, the more
likely a violent outburst could happen in the
direction of Earth.
We call these outbursts “Coronal Mass
Ejections” and they can cause huge amounts
of damage to our electronic systems and
satellites.
We’ll study these later in more detail.
Sunspots
Sunspots also appear and disappear in
numerical patterns. Every certain number of
years, the number of sunspots increases
dramatically, then a few years later falls off
again.
We call the high point of this cycle the “solar
maximum”. The low point is called the “solar
minimum”.
We’ll look at this more in detail later, but we
have data reaching back on sunspots to the
mid 1600s so the patterns we know are very
established.
Graphing Sunspots
It’s been of interest for scientists to note how many
sunspots appear each year so we can discover if there’s
an underlying nature of the sun for us to discover.
We’re going to replicate this activity a bit. Each of you is
going to graph a span of real sunspot data. We’ll then put
the data together and see what patterns we find.
Pick a set of data on the next slide and start graphing it
with bar graphs. We’ll continue this activity both today
and tomorrow.
Graphing Sunspots
Year
# of spots
Year
# of spots
Year
# of spots
Year
# of spots
1955
38
1970
104.5
1985
17.9
2000
119
1956
141.7
1971
66.6
1986
13.4
2001
110.9
1957
190.2
1972
68.9
1987
29.4
2002
104
1958
184.8
1973
38
1988
100.2
2003
63.7
1959
159
1974
34.5
1989
157.6
2004
40.4
1960
112.3
1975
15.5
1990
142.2
2005
29.8
1961
53.9
1976
12.6
1991
145.8
2006
15.2
1962
37.6
1977
27.5
1992
94.5
2007
7.5
1963
27.9
1978
92.5
1993
54.7
2008
2.9
1964
10.2
1979
155.4
1994
29.9
2009
3.1
1965
15.1
1980
154.6
1995
17.9
2010
1966
47
1981
140.4
1996
8.6
2011
16.5
55.6
1967
93.8
1982
115.9
1997
21.5
2012
57.6
1968
105.9
1983
66.6
1998
64.3
2013
64.7
1969
105.5
1984
45.9
1999
93.3
2014
79.3
Exit Question
What would we see if the sun had a stronger magnetic
field?
a) more sunspots
b) Less sunspots
c) Same number but in different location
d) One big sunspot
e) No difference