MUSE image of the Saturn Nebula
Three-dimensional MUSE view of the Saturn Nebula
Annotated image showing features in the Saturn Nebula
The Saturn Nebula in the constellation of Aquarius
The sky around the Saturn Nebula
Videos
ESOcast 129 Light: The Strange Structures of the Saturn Nebula (4K UHD)
Looking at the Saturn Nebula in 3D
Zooming in on the Saturn Nebula
The spectacular planetary nebula NGC
7009, or the Saturn Nebula, emerges from the darkness like a series of
oddly-shaped bubbles, lit up in glorious pinks and blues. This colourful
image was captured by the powerful MUSE instrument on ESO’s Very Large
Telescope (VLT), as part of a study which mapped the dust inside a
planetary nebula for the first time. The map — which reveals a wealth of
intricate structures in the dust, including shells, a halo and a
curious wave-like feature — will help astronomers understand how
planetary nebulae develop their strange shapes and symmetries.
The Saturn Nebula is located approximately 5000 light years away in the constellation of Aquarius (The Water Bearer). Its name derives from its odd shape, which resembles everyone’s favourite ringed planet seen edge-on.
But in fact, planetary nebulae have nothing to do with planets. The Saturn Nebula was originally a low-mass star, which expanded into a red giant
at the end of its life and began to shed its outer layers. This
material was blown out by strong stellar winds and energised by ultraviolet
radiation from the hot stellar core left behind, creating a
circumstellar nebula of dust and brightly-coloured hot gas. At the heart
of the Saturn Nebula lies the doomed star, visible in this image, which
is in the process of becoming a white dwarf [1].
In order to better understand how planetary nebulae are
moulded into such odd shapes, an international team of astronomers led
by Jeremy Walsh from ESO used the Multi Unit Spectroscopic Explorer
(MUSE) to peer inside the dusty veils of the Saturn Nebula. MUSE is an
instrument installed on one of the four Unit Telescopes of the Very Large Telescope
at ESO’s Paranal Observatory in Chile. It is so powerful because it
doesn’t just create an image, but also gathers information about the
spectrum — or range of colours — of the light from the object at each
point in the image.
The team used MUSE to produce the first detailed optical maps of the gas and dust distributed throughout a planetary nebula [2].
The resulting image of the Saturn Nebula reveals many intricate
structures, including an elliptical inner shell, an outer shell, and a
halo. It also shows two previously imaged streams extending from either
end of the nebula’s long axis, ending in bright ansae (Latin for
“handles”).
Intriguingly, the team also found a wave-like feature in
the dust, which is not yet fully understood. Dust is distributed
throughout the nebula, but there is a significant drop in the amount of
dust at the rim of the inner shell, where it seems that it is being
destroyed. There are several potential mechanisms for this destruction.
The inner shell is essentially an expanding shock wave, so it may be
smashing into the dust grains and obliterating them, or producing an
extra heating effect that evaporates the dust.
Mapping the gas and dust structures within planetary
nebulae will aid in understanding their role in the lives and deaths of
low mass stars, and it will also help astronomers understand how
planetary nebulae acquire their strange and complex shapes.
But MUSE’s capabilities extend far beyond planetary
nebulae. This sensitive instrument can also study the formation of stars
and galaxies in the early Universe, as well as map the dark matter distribution in galaxy clusters in the nearby Universe. MUSE has also created the first 3D map of the Pillars of Creation in the Eagle Nebula (eso1518) and imaged a spectacular cosmic crash in a nearby galaxy (eso1437).
Notes
[1] Planetary nebulae are generally short-lived; the Saturn Nebula
will last only a few tens of thousands of years before expanding and
cooling to such an extent that it becomes invisible to us. The central
star will then fade as it becomes a hot white dwarf.
[2] The NASA/ESA Hubble Space Telescope has previously provided a spectacular image of the Saturn Nebula — but, unlike MUSE, it cannot reveal the spectrum at each point over the whole nebula.
More Information
ESO is the foremost intergovernmental astronomy organisation in Europe
and the world’s most productive ground-based astronomical observatory by
far. It is supported by 16 countries: Austria, Belgium, Brazil, the
Czech Republic, Denmark, France, Finland, Germany, Italy, the
Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United
Kingdom, along with the host state of Chile. ESO carries out an
ambitious programme focused on the design, construction and operation of
powerful ground-based observing facilities enabling astronomers to make
important scientific discoveries. ESO also plays a leading role in
promoting and organising cooperation in astronomical research. ESO
operates three unique world-class observing sites in Chile: La Silla,
Paranal and Chajnantor. At Paranal, ESO operates the Very Large
Telescope and its world-leading Very Large Telescope Interferometer as
well as two survey telescopes, VISTA working in the infrared and the
visible-light VLT Survey Telescope. ESO is also a major partner in two
facilities on Chajnantor, APEX and ALMA, the largest astronomical
project in existence. And on Cerro Armazones, close to Paranal, ESO is
building the 39-metre Extremely Large Telescope, the ELT, which will
become “the world’s biggest eye on the sky”.
Links
- Photos of the VLT
- Photos of MUSE
- Press release on first light of MUSE
Contacts
