A TOEFL Integrated essay on supernovae

This is an example of an integrated essay on the TOEFL (Test of English as a Foreign Language). This essay responds to the writing task on page 407 of the Longman Preparation Course for the TOEFL. Students have three minutes to read the passage on supernovae. They then listen to a lecture on the same topic and write their essays within the 20-minute time limit.

It's important to write a well-organized essay, to have a clear thesis statement, which is the answer to the question, and to convey how the listening relates to the reading. Students should spend 2 minutes in the beginning to prepare a rough outline and leave 2 minutes in the end to edit their work before time runs out.

QUESTION: How does the information in the reading passage contrast with the information in the listening passage?

ESSAY:

This set of materials talks about supernovae, a celestial phenomenon that occurs when a star explodes. While the reading discusses the type 1 supernova, the listening talks about the type 2 kind.

According to the reading, a type 1 supernova only occurs when two stars exist next to each other and one star becomes a white dwarf, which is a star that has shrunk and is on the verge of collapse. Its companion star, on the other hand, continues to grow and eventually has to stop expanding once it comes in contact with the white dwarf. When this happens, material from the large star transfers into the white dwarf, and when the white dwarf grows to a critical mass (1.4 times that of the sun), the white dwarf explodes. This explosion is called a supernova, and it has been seen by the naked eye twice in recorded history, but more has been observed since the invention of the telescope.

On the other hand, the listening describes a type 2 supernova. The lecturer mentions that in a type 2 supernova, only one star is involved. This star is in the process of dying. It has become massive; its core is getting hotter and hotter, and once it reaches its critical mass or ten times the size of the sun, it collapses and explodes in a thermonuclear reaction, which is also called a supernova event. According to the professor, the most famous type 2 supernova was observed in China and was visible to the naked eye for 23 days in daylight and for a period of about two years at night. In 1987, another type 2 supernova was observed. This one was said to have occured close enough to the Milky Way galaxy and was strong enough to be seen by the naked eye.


This sample essay was written by Joe Yu, ESL instructor.