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 SN 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 this lab.

1) Astronomers study these supernova events for they often contain information that:

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 space

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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