Nebula - Cat's Eye (NGC 6543)

8/9/2019 Nebula - Cat's Eye (NGC 6543)

1/4

National Aeronautics and Space Administration

Cats Eye Nebula (NGC 6543)

www.nasa.gov
http://www.nasa.gov/http://www.nasa.gov/http://www.nasa.gov/http://www.nasa.gov/http://www.nasa.gov/


2/4

A Sun-like Stars Last Hurrah

This image reveals new details o the Cats Eye Nebula (catalogued as NGC 6543), one

o the most complex planetary nebulae ever seen. A planetary nebula is the glowing gasejected during the nal stages o evolution o a star similar in mass to our Sun.Planetary nebulae are like snowfakes: no two look alike. When a Sun-like star nears the

end o its lie, it expands in size to become a bloated red giant, with a diameter about 100times greater than its original size. The star then ejects its outer layers into space, exposingits hot core. Ultraviolet radiation rom the central core streams out into the surroundingejected gas, causing it to glow. The glowing gas is called a planetary nebula, so-namedbecause its round shape resembles that o a planet when viewed with a small telescope.Over the next several thousand years, the nebula will gradually disperse into space, andthen the star will cool and ade away or billions o years as a white dwar. Our Sun isexpected to undergo a similar ate, but not or another 5 billion years. Astronomers still donot ully understand many details o the process that lead a star to lose its gaseous enve-

lope. The study o planetary nebulae is one o the ew ways to recover inormation aboutthese last ew thousand years in the lie o a Sun-like star.

The expelled gas rom the dying, central star has intr iguing symmetrical patterns as wellas more chaotic structures. Scientists are trying to understand how a spherical star canproduce such prominent, non-spherical symmetries in the gas that it ejects.

Astronomers have considered several mechanisms to explain the shapes o planetarynebulae. One possible explanation is that the stars magnetic eld aects the shape.Another is that a companion star exerts a strong gravitational orce on the ejected gas andsculpts it into the patterns we see. Trying to explain these complex patterns is dicultbecause we view planetary nebulae rom Earth and cannot move around them to see theirthree-dimensional structure.

The Hubble telescope has made several observations o the Cats Eye. This image, takenwith Hubbles Advanced Camera or Surveys, reveals the ull beauty o a bulls eye patterno 11 or more concentric rings, or shells, around the dying star. Each ring is actually theedge o a spherical bubble seen projected onto the sky that is why the nebula appearsbright along its outer edge. These rings suggest that the initial ejection o gas rom the starwas episodic, recurring about every 1,500 years. Observations with the Hubble telescopewere the rst to reveal these puzzling concentric rings, which have now been seenaround a number o planetary nebulae.

Hubbles images o the Cats Eye and other planetary nebulae are revealing many newmysteries o these glowing patterns o gas spun into space by dying stars.

VOCABULARY

Red giant:When a Sun-like star nears the end o its lie, its outer layers expand in size andbecome cooler, orming a bright star much larger and cooler than the Sun.

White dwarf: The hot, compact remains o a low-mass star like our Sun that has exhaustedits sources o uel or thermonuclear usion.

You can get images and other information about the Hubble Space Telescope on theWorld Wide Web. Visit http://www.stsci.edu/outreachand follow the links.

The corresponding classroom activity for this lithograph can be found at:http://amazing-space.stsci.edu/ or may be obtained by contacting the Office ofPublic Outreach at the Space Telescope Science Institute, 3700 San Martin Drive,

Baltimore, MD 21218.

STScI L-05-05 LG-2005-9-95-GSFC


Goddard Space Flight Center

Cats Eye Nebula (NGC 6543)

A Nebula Gallery.Above is a sampling o nebulae imaged by the HubbleSpace Telescope: The Helix Nebula (A ), Little Ghost Nebula (B), Ant Nebula(C ), Spirograph Nebula (D), and Eskimo Nebula (E).

Credits: Helix Nebula: NASA, ESA, C.R. ODell (Vanderbilt University), and M.Meixner, P. McCullough (STScI); Little Ghost, Ant, and Spirograph Nebulae:NASA and TheHubble HeritageTeam (STScI/AURA); Eskimo Nebula: NASA, A.

Fruchter, and the ERO Team (STScI).

FAST FACTSLocation: Constellation Draco.Distance from Earth: 3,000 light-years.

Credits: R. Corradi (Isaac Newton Group of Telescopes, Spain), Z. Tsvetanov (NASA).
http://www.nasa.gov/http://www.gsfc.nasa.gov/http://www.nasa.gov/http://www.esa.int/esaCP/index.htmlhttp://www.stsci.edu/resources/http://heritage.stsci.edu/http://www.stsci.edu/http://www.aura-astronomy.org/http://www.nasa.gov/http://www.stsci.edu/resources/http://www.stsci.edu/resources/http://www.nasa.gov/http://www.aura-astronomy.org/http://www.stsci.edu/http://heritage.stsci.edu/http://www.stsci.edu/resources/http://www.esa.int/esaCP/index.htmlhttp://www.nasa.gov/http://www.nasa.gov/http://www.gsfc.nasa.gov/http://www.nasa.gov/


3/4


In Search of the Complex Structures of Planetary Nebulae

Description

Using the Cats Eye Nebula (NGC 6543) lithograph, engage your students ina Level One Inquiry activity to compare the complex structures o planetarynebulae. A Level One Inquiry activity can help prepare students to be moreindependent thinkers. Students conduct research to answer questions theyhave about planetary nebulae.

Grade Level

High school, grades 912

Prerequisites

Students should know that stars vary in brightness, color, age, temperature,and mass, and that mass determines a stars ate. Students should also be awarethat normal stars, like the Sun, use hydrogen in their cores. The depletion othis uel source initiates the fnal stages in the lie o a star, resulting, or Sun-like stars, in a planetary nebula.

Misconceptions

Teachers should be aware o the ollowing common misconceptions anddetermine whether their students harbor any o them. Students may have

misconceptions regarding the evolution and ate o stars. The name planetarynebula in itsel is misleading. Students may think that planetary nebulae areassociated with planets, when, in act, they have nothing to do with them.The name originates rom William Herschel, who thought their uzzy shapesresembled the disks o the outer planets as seen through small telescopes. Thename remains despite the act that it represents a late stage in the lives o low-mass, Sun-like stars.

Students may think all stars end their lives in the same way as superno-vae. Whether a star becomes a planetary nebula or a supernova depends on itsoriginal mass. The Sun and other less massive stars will orm planetary nebulae.

Students may think that stars dont change. The act is that stars evolve overbillions o years. Most stellar changes, such as the birth o a star, occur overmany human lietimes.

Purpose

The purpose o this activity is to apply a Level One Inquiry technique, us-ing images and text to compare the complex structures o planetary nebulae.In this activity, the components o inquiry learning that students can practiceare: asking questions, planning and conducting investigations, using critical-thinking skills, making comparisons, and communicating results. Students willmake comparisons, develop questions, and read or a purpose.

Materials

Cats Eye Nebula (NGC 6543) lithograph.

Computer with Internet connection or researching answers.

Instructions for the Teacher

Preparation

Obtain a lithograph or each student. Lithographs are available as PDF fles athttp://amazing-space.stsci.edu/eds/tools/type/pictures.php.

Familiarize yoursel with the evolution o Sun-like stars using a currentastronomy textbook or the AstroFile: The Glorious End o Stellar Lie: http:

//hubblesite.org/newscenter/archive/1997/38/astrofle.

Bookmark or identiy as avorites the ollowing suggested Web sites and/or pre-pare a list o Web sites that students can access to obtain additional inormationabout planetary nebulae.

Space Telescope Science Institute (STScI): Stellar Evolution Press Releases andImages:http://hubblesite.org/newscenter/newsdesk/archive/releases/category/nebula/planetary/.

STScI Planetary Nebula Gallery: http://oposite.stsci.edu/pubino/pr/97/pn/photo-gallery.html.

STScI Dying Star Creates Fantasy-like Sculpture o Gas and Dust: http:

//hubblesite.org/newscenter/newsdesk/archive/releases/2004/27/.STScI Planetary Nebulae: A Cosmic Funeral:http://hubblesite.org/discoveries/tour_the_cosmos/july_98/nebula/index.shtml.

www.nasa.gov
http://www.nasa.gov/http://amazing-space.stsci.edu/eds/tools/type/pictures.phphttp://hubblesite.org/newscenter/archive/1997/38/astrofilehttp://hubblesite.org/newscenter/archive/1997/38/astrofilehttp://hubblesite.org/newscenter/newsdesk/archive/releases/category/nebula/planetary/http://hubblesite.org/newscenter/newsdesk/archive/releases/category/nebula/planetary/http://oposite.stsci.edu/pubinfo/pr/97/pn/photo-gallery.htmlhttp://oposite.stsci.edu/pubinfo/pr/97/pn/photo-gallery.htmlhttp://hubblesite.org/newscenter/newsdesk/archive/releases/2004/27/http://hubblesite.org/newscenter/newsdesk/archive/releases/2004/27/http://hubblesite.org/discoveries/tour_the_cosmos/july_98/nebula/index.shtmlhttp://hubblesite.org/discoveries/tour_the_cosmos/july_98/nebula/index.shtmlhttp://www.nasa.gov/http://www.nasa.gov/http://hubblesite.org/discoveries/tour_the_cosmos/july_98/nebula/index.shtmlhttp://hubblesite.org/discoveries/tour_the_cosmos/july_98/nebula/index.shtmlhttp://hubblesite.org/newscenter/newsdesk/archive/releases/2004/27/http://hubblesite.org/newscenter/newsdesk/archive/releases/2004/27/http://oposite.stsci.edu/pubinfo/pr/97/pn/photo-gallery.htmlhttp://oposite.stsci.edu/pubinfo/pr/97/pn/photo-gallery.htmlhttp://hubblesite.org/newscenter/newsdesk/archive/releases/category/nebula/planetary/http://hubblesite.org/newscenter/newsdesk/archive/releases/category/nebula/planetary/http://hubblesite.org/newscenter/archive/1997/38/astrofilehttp://hubblesite.org/newscenter/archive/1997/38/astrofilehttp://amazing-space.stsci.edu/eds/tools/type/pictures.phphttp://www.nasa.gov/http://www.nasa.gov/


4/4

Goddard Space Flight Center STScI L-05-05 LG-2005-9-95-GSFC

Procedure

Beore beginning this activity, evaluate your students misconceptionsabout planetary nebulae by having them write down anything they knowand understand about the end o a Sun-like stars lie. Have students tell whatthey know about planetary nebulae. From those ideas, identiy their miscon-ceptions and discuss them with the class. Or, collect the papers containingtheir ideas about planetary nebulae. From those ideas, compile a list o their

misconceptions and discuss them with the class.Ask students to look at the images o the Cats Eye Nebula on the ront and

the other planetary nebulae on the back. Ater they have studied the photos,have them write down three questions they want answered about planetarynebulae. Compile a list o questions, and group students by common theme.

Ask students to read the inormation on the back o the lithograph, andcheck i any o their questions have been answered. Allow students to refnetheir questions by discussing them with their group. Ask students to use theInternet to research their questions. The Internet sites listed previously canprovide a starting point or their research. Instruct students on how to accessother Web sites that may be appropriate.

Ask students to prepare a report in which they compare planetary nebulaemorphology. This report could be in the orm o a slide show, a skit, a story, agraphic organizer, a Power Point presentation, or a written report anythingthat conveys their understanding o the topic to another student, a group ostudents, or the entire class. Ask students to review their original questions tosee i they were answered. Then ask them i they have any additional ques-tions.

Instructions for the StudentYour teacher will ask you to write down things you know and understand

about planetary nebulae. You may be asked to share this inormation with therest o the class. Study the images o the planetary nebulae, and write downthree questions about what you see in those pictures. Then read the back othe lithograph and check i any o your questions were answered.

Your teacher will assign you to a group to research the answers to yourquestions. You can search or your answers on Internet sites that your teacher

will provide to you. To demonstrate your understanding, your teacher will askyou to give a report that compares the similarities and dierences betweenplanetary nebulae structures. This report could be a slide show, a skit, a story,a graphic organizer, a Power Point presentation, or whatever presentation youthink will communicate the inormation you learned about planetary nebulae.

You may be allowed to work individually or in small groups, and make yourpresentations to another classmate, another group o students, or the entireclass.

Education Standards

Benchmarks for Science Literacy

American Association for the Advancement of Science:

http://www.project2061.org/tools/benchol/bolrame.htm

1. The Nature o Science

A. The Scientifc World ViewBy the end o the 12th grade, students should know that: No matter how well one theory fts observations, a new theory might ftthem just as well or better, or might ft a wider range o observations. Inscience, the testing, revising, and occasional discarding o theories, newand old, never ends. This ongoing process leads to an increasingly betterunderstanding o how things work in the world but not to absolute truth.Evidence or the value o this approach is given by the improving ability oscientists to oer reliable explanations and make accurate predictions.

B. Scientifc Inquiry

By the end o the 12th grade, students should know that: Investigations are conducted or dierent reasons, including: to explore newphenomena, to check on previous results, to test how well a theory predicts,and to compare dierent theories.
http://www.gsfc.nasa.gov/http://www.project2061.org/tools/benchol/bolframe.htmhttp://www.project2061.org/tools/benchol/bolframe.htmhttp://www.gsfc.nasa.gov/

Documents

Nebula - Cat's Eye (NGC 6543)