Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
February 9, 1996
The Eye of an Hourglass Nebula
Credit:
R. Sahai and J. Trauger (JPL),
WFPC2 Science
Team,
NASA
Explanation: What's happening in the eye-like center of this planetary nebula? The geometry revealed in this Hubble Space Telescope view of the central part of an "etched hourglass nebula" known as MyCn 18 presents a puzzle. First, the axis of this central region does not line up well with the outer hourglass structure. Next, the hot star (the white spot to the left of center) which ejected this gaseous nebula as it evolved towards its white dwarf phase, is not exactly at the center of the "eye". These unexpected results leave astronomers looking for the missing pieces of the ejection process that created this unusual and beautiful structure.
Authors & editors:
Robert Nemiroff
(GMU) &
Jerry
Bonnell (USRA).
NASA Technical Rep.:
Sherri
Calvo.
Specific rights apply.
A service of:
LHEA
at
NASA/
GSFC
