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The Science behind theEagle Nebula Image
Howard E. Bond
Space Telescope Science Institute
and
Co-founder, Hubble Heritage Team
Dust pillar in theEagle Nebula, Messier 16
Credit: NASA, ESA,and the Hubble Heritage Team
What’s this?
The Hubble Heritage Program
• Founded in 1998 to bring the most compelling Hubble images to the public
• Main criterion is pictorial beauty, with scientific interest also considered
• Images are taken from archive, sometimes supplemented by new observations obtained by the Heritage team through Director’s Discretionary time, and processed for release
The Hubble Heritage Program
• Some observations, including the Eagle Nebula Pillar released today, are entirely new images obtained by Heritage team
• Prizes & honors:– Images on US & British postage stamps– 2003 Klumpke-Roberts Award of the
Astronomical Society of the Pacific for contributions to public appreciation of astronomy
Amateur Photograph of M16
M16 is an emission nebula or H II region;red color is due to ionized hydrogen gas
Star Formation in the Eagle Nebula
• Dense cloud of interstellar gas, molecules, & dust contracts under its own gravity
• Massive, hot, blue stars form inside the cloud
• Stellar winds and UV light push gas & dust away
• Dense clouds can resist this erosion longer, forming pillars pointing back toward hot stars
Blue = oxygen atoms ionized by UV light
Dark = dense dust & molecules
Gas evaporating off pillar
Dust & gas compressedby stellar winds, formingnew stars—currently visible only in infraredlight
Red = cooler hydrogen &nitrogen ions
Visible-light and Infrared Images
Hubble Infrared Space Observatory
IR revealsvery youngstarsembeddedIn dust
Summary
• The pillars in the Eagle Nebula illustrate some of the complex events that accompany the formation of new stars
• First-generation stars produce a cavity in their dust cocoons with pillars pointing back to the hot young stars
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