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Astronomy Picture of the Day |
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Astronomy Picture of the Day |
APOD: 2008 December 17 - The Dumbbells
Explanation:
These two nebulae are cataloged as M27 (left) and M76,
popularly known as
The Dumbbell and the
Little Dumbbell.
Not intended to indicate
substandard mental prowess,
their popular names refer to their similar,
dumbbell or hourglass shapes.
Both are planetary nebulae, gaseous shrouds cast off by
dying sunlike
stars, and are similar in physical size, at a light-year or
so across.
In each panel, the images were made at the same scale, so the
apparent size difference is mostly because one is closer.
Distance estimates suggest 1,200 light-years for the Dumbbell
compared to 3,000 light-years or more for the Little Dumbell.
These deep, narrow-band, false-color
images show some remarkably
complex structures
in M27
and M76,
highlighting emission from hydrogen,
nitrogen, and oxygen atoms within the cosmic clouds.
APOD: 2008 November 21 - M76 Above and Below
Explanation:
Also known by the popular name the "Little Dumbbell Nebula",
M76 is
one of the fainter objects listed in Charles Messier's 18th century
Catalog of
Nebulae and Star Clusters.
Like its better-known namesake M27
(the Dumbbell Nebula), M76 is recognized
as a planetary
nebula - a gaseous shroud cast off by a
dying sunlike star.
The nebula itself is thought to be shaped more like a donut, its
central box-like appearance
due to our nearly edge-on view.
Gas expanding more rapidly away from the donut hole produces the
more extensive, far flung material in
this remarkable image
that uses narrow-band
filters to highlight the
emission from hydrogen (in red) and
oxygen atoms (in greenish blue).
In particular, complex oxygen emission features are seen
above and below the main nebula to a degree not detected
in most images of M76.
Distance estimates place M76 about 3 to 5 thousand light-years away
toward the heroic constellation
Perseus,
making the nebula over a
light-year in diameter.
APOD: 2006 November 2 - Messier 76
Explanation:
"Nebula at the right foot
of
Andromeda ... " begins the description
for the 76th object in Charles Messier's 18th century Catalog
of
Nebulae and Star Clusters.
In fact, M76 is
one of the fainter objects on the Messier list and
is also known by the popular name of the "Little Dumbbell Nebula".
Like its brighter namesake M27
(the Dumbbell Nebula), M76 is recognized
as a planetary
nebula - a gaseous shroud cast off by a
dying sunlike star.
The nebula itself is thought to be shaped more like a donut, while its
box-like appearance is
due to our nearly edge-on view.
Gas expanding more rapidly away from the donut hole produces the
faint loops of far flung material.
The nebula's dying star can be picked out in
this sharp color image as
the bottom, blue-tinted member of the double star near the center
of the box-like shape.
Distance estimates place M76 about 3 to 5 thousand light-years away,
making the nebula over a
light-year in diameter.
