Helix Nebula NGC 7293

Despite public misconception the Hubble Space Telescope did not take this picture. However, it is a compilation of photographs from the Hubble and another ground-based telescope.

The Helix Nebula is one of the closest of all planetary nebulae: Lying at a distance of perhaps 450 light years, it is the only planetary nebula for which a parallax could be obtained by ground-based observations. Nevertheless, its distance is quite uncertain: The first determination by A. Van Maanen yielded about 85 light-years, the Sky Catalogue 2000.0 gives about 300 ly, and C.R. O'Dell (1963) obtains 450 light-years.

It is also one of the apparently largest planetaries known: Its apparent size covers an area of 16 arc minutes diameter, more than half of that of the full moon; its halo extends even further to 28 arc minutes or almost the moon's apparent diameter. Although the nebula is quite bright, its light is spread over this large area so that it is not an easy object for visual observing.

The popular name Helix Nebula refers to the nebula's appearance on photographs prior to 2003. The graphic above was produced by superimposing Hubble photographs with those from Kitt Peak telescope.

Technical information

• Name: Helix Nebula, NGC 7293
• Description: Planetary Nebula
• Position (J2000): R.A. 22h 29m 48.20s
• Dec. -20 degrees 49 minutes 26.0 seconds
• Constellation: Aquarius
• Distance: About 650 light-years (200 parsecs)
• Dimensions: The image is roughly 27 arcminutes (5.1 light-years or 1.6 parsecs) across.

* Hubble data have been superimposed onto ground-based data taken by Travis Rector (NRAO) at the 0.9 meter telescope located on Kitt Peak, Tucson, AZ (NOAO/AURA/NSF). The HST data are from proposal 9700. Processed images may be obtained from the Helix MAST web site. The Hubble Helix Team includes M. Meixner, H.E. Bond, G. Chapman (STScI), Y.-H. Chu (U. Illinois, Urbana-Champaign), P. Cox (Institut d'Astrophysique Spatiale, France), W. Crothers, L.M. Frattare, R.Gilliland (STScI), M. Guerrero R. Gruendl (U. Illinois, Urbana-Champaign), F. Hamilton, (STScI), R.Hook (STScI/ESO), P. Huggins (New York Univ.), I. Jordan, C.D. Keyes, A. Koekemoer (STScI), K.Kwitter (Williams College), Z.G. Levay, P.R. McCullough, M. Mutchler, K. Noll (STScI), C.R. O'Dell (Vanderbilt Univ.), N. Panagia, M. Reinhart, M. Robberto, K. Sahu, D. Soderblom, L. Stanghellini, C. Tyler, J. Valenti, A. Welty, R. Williams (STScI).

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