No filter. Visible only as a slight darkening of the background sky. Averted vision begins to reveal helical structure, lobed appearance.
sketches : Nebulae : NGC 7293 Helix Nebula PN 11-22-2003 |
Back |
NGC 7009 Saturn Nebula PN 11-06-2004 |
NGC 7293 Helix Nebula PN 11-22-2003 |
NGC 7009 Saturn Nebula PN 11-06-2004 |
NGC 7293 Helix Nebula PN 11-22-2003 |
Copyright © 2003-2007 Michael Portuesi. See the front page for licensing information.