NASA Astronomy Picture of the Day Collection

At the Edge of the Helix Nebula

While exploring the inner edge of the Helix Nebula [ http://antwrp.gsfc.…] with the Hubble Space Telescope [ http://antwrp.gsfc.…]'s Wide Field Planetary Camera 2 [ http://www.stsci.ed…], astronomers were able to produce this striking image [ http://oposite.stsc…] - rich in details of an exotic environment. This planetary nebula [ http://www.noao.edu…], created near the final phase of a sun-like [ http://instruct1.ci…] star's life [ http://antwrp.gsfc.…], is composed of tenuous shells of gas ejected by the hot central star. The atoms [ http://education.jl…] of gas, stripped of electrons [ http://www.aip.org/…] by ultraviolet radiation [ http://liftoff.msfc…] from the central star, radiate light at characteristic energies allowing specific chemical elements [ http://pearl1.lanl.…] to be identified. In this image [ http://oposite.stsc…], emission from nitrogen [ http://pearl1.lanl.…] is represented as red, hydrogen [ http://pearl1.lanl.…] emission as green, and oxygen [ http://pearl1.lanl.…] as blue. The inner edge of the Helix Nebula [ http://www.seds.org…], also known as NGC 7293, is in the direction toward the central star, which is toward the upper right. Clearly visible near the inner edge are finger shaped cometary knots [ http://antwrp.gsfc.…].

R. O'Dell and K. Handron (Rice University [ http://space.rice.e…]), NASA [ http://www.nasa.gov/]

planetary nebula

Helix Nebula

NGC 7293

Goddard Space Flight Center (GSFC)

Marshall Space Flight Center (MSFC)

Sun

Camera 2

Wide Field Planetary Camera 2

nebula

Hubble Space Telescope (HST)

http://antwrp.gsfc.…

SPD-APOD-ap020512