From the National Optical Astronomical Observatories
This is a color composite infrared image using adaptive optics on the Gemini North telescope. The stellar images show remarkable resolution that approaches the theoretical limit for an 8 meter telescope. (Resolution = 0.083 arc seconds FWHM) In this Gemini near infrared image the young planetary nebula BD +30 3639 is glowing in the light of hydrogen, the most abundant element in the universe. It is about ten thousand light years from the Earth in the direction of the constellation of Cygnus. The sharpness of the star images, particularly apparent for the fainter stars around BD +30 3639, approaches the best image quality achievable with this size telescope at these wavelengths, promising a rich future of superb images from the Gemini telescopes.
This image was taken by the Gemini North 8-meter telescope on Mauna Kea using the University of Hawaii's Adaptive Optics system Hokupa'a. Adaptive Optics systems use deformable mirrors to correct for the effects of atmospheric distortions to starlight, resulting in significantly sharper images. Adaptive Optics will allow Gemini to at times produce sharper images than is possible with the Hubble Space Telescope.
A few million years ago BD +30 3639 was a star similar to our sun, but since then it has evolved, first into a red giant, and then more rapidly into the planetary nebula seen today. In the red giant phase, the center of the star heats up and drives off its outer layers. In the subsequent Planetary Nebula phase, the ejected material is heated by ultraviolet radiation from the hot central star until it begins to glow. In a few tens of thousands of years (a short time by astronomical standards) the ejected material will be dispersed into the interstellar medium and the central star will slowly cool and eventually disappear.
The bright box-like ring seen around the central star is due to emission from hydrogen in the material ejected during the red giant phase that has already been heated by the central star. This enormous shell is approximately one hundred times larger than our solar system. An unusual feature of this planetary nebula is the outer fainter and more wispy emission from molecular hydrogen. This larger shell of ejected material has yet to be broken apart by ultraviolet radiation from the star. The wispy structures visible in the light of molecular hydrogen reveals information about the extent of the ejected material and details about the dynamic processes involved in recycling material from stars back into interstellar space.
Image Title: The Planetary Nebula BD +30 3639
Credit: Gemini Observatory, US National Science Foundation, and the University of Hawaii Institute for Astronomy.
Text based on accompanying on-line materials.
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Last Modified On: Saturday, December 16, 2000