Supernova 1987 A
In this webpage are a series of scanned pages from my "Activities
in Astronomy" lab book. The assignment is here, but
the form you submit it to me on is at Supernova
1987a Lab. Since I have blatantly copied these pages for this exercise,
I want to take time to give credit to Darrel B. Hoff, the chief author and editor.
Kendall/Hunt Publishing Company in Dubuque, Iowa, 1996. Since I am using these
pages entirely for the purposes of education and not for resale or profit in
my part or that of Hopkins On-line Academy, I believe that the "Fair
Use" rules of the Internet apply, and that I am fully within those
guidelines. If I were in a classroom setting, I would make copies of these pages
for those students as well.
On to the Supernova that occurred in 1987 and an explanation
of the images below:
Above and to the left is a nice photo of the Large Magellanic Cloud. This
irregular galaxy is about 170,000 light years from Earth and is a close neighbor
to the Milky Way. In the center of the left image, near the top, is a pink region
of nebulosity called the Tarantula Nebula. Angling down and slightly to the
left is the area where the supernova occurred. The image above and to the right
shows that region of the LMC, but rotated counterclockwise for better viewing.
The bright star to the lower right of that image is the SN 1987A event.
Below, and to the left is a closer look at the event as it appeared 12 years
later, and to the right of that picture is a close-up of the rings of expanding
gas. I just think these pictures are so cool!
Below is an extreme close-up image of SN 1987A. All of these images are courtesy
of the NOAO/AURA.
A little about SN 1987A and what you are to do for this lab:
Astronomers were greeted in February 23, 1987 with a relatively
nearby supernova. A star in the Large Magellanic Cloud (above) erupted. Such
an event has not taken place in the Milky Way for almost 400 years, so they
are rare events for a galaxy (most estimate an average of one supernova per
galaxy per 100 years, so our Milky Way is long overdue). Since the LMC is so
close to us, astronomers were able to witness the event and make some detailed
observations. I want you to go through the pages I have scanned and complete
the data sheet and graph at your home. Then I would like you to go to a similar
1987A page where you can submit your final answers to me over the internet.
Before you begin, there are a few key points to helping you complete
1) Astronomers study these supernova events for they often contain
a) helps them understand the evolution of stars
b) helps them understand the origin of elements
c) helps them understand the distance to far away objects in
2) There are two main classes of supernova events (Type I and
Type II), and both are critical to answering the first two levels of understanding
listed above. However, there is a distinct difference between the way the two
classes of stars explode. The light curve of a Type I event is different in
form and magnitude of brightening from that of a Type I event. As you can see
from the comparitive graph below, the curve of a Type I event is higher in terms
of absolute brightness and steadily dims over time. The Type II event does not
get as bright and dims more slowly over time. To learn more about these events
go to Supernovae
in this course.
3) Astronomers measure distance in space using the measure of
parsecs. One parsec is the same as 3.26 light years.
4) Astronomers study supernova events, looking for Type I events
because they all originate from the sudden collapse of a White
Dwarf that exceeds the mass limit of 1.44 Solar Masses. Type II events originate
from massive stars that suddenly implode and explode, and their masses at the
time of eruption are different every time. Type
I events start with the same mass so it is assumed that they will explode
in the same manner every time. The Type I supernovae events are real good for
measuring the distance to galaxies because they always explode from similar
starting circumstances and explode the same way because they are composed of
similar material. If their eruptive events are so similar, they could be used
as a standard
candle to help astronomers determine the distance to a far away galaxy where
such an event might be witnessed.
THE PURPOSE OF THIS LAB IS TO DETERMINE WHAT KIND OF EVENT THE
1987 SUPERNOVA WAS.
From the data you have collected, there is one critical question for you to
answer ... is SN 1987A a Type I or a Type II Supernova event. Please consider
the light curve as well as the maximum brightness in your answer. If the graph
paper does not print out from this site, then go to the SN 1987A graph page
to get it. You do not need to submit the light curve to me, but you will need
to generate one from the data in order to determine whether this was a Type
I or Type II event.
Please move forward to the mirror SN
1987A page where you can put your answers in little boxes and send them
to me over the internet.
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