The Twin Jet Nebula
The night sky around the Twin Jet Nebula (ground-based image)
Videos
Panning across the Twin Jet Nebula
The shimmering colours visible in this
NASA/ESA Hubble Space Telescope image show off the remarkable complexity
of the Twin Jet Nebula. The new image highlights the nebula’s shells
and its knots of expanding gas in striking detail. Two iridescent lobes
of material stretch outwards from a central star system. Within these
lobes two huge jets of gas are streaming from the star system at speeds
in excess of one million kilometres per hour.
The cosmic butterfly pictured in this NASA/ESA Hubble Space Telescope
image goes by many names. It is called the Twin Jet Nebula as well as
answering to the slightly less poetic name of PN M2-9.
The M in this name refers to Rudolph Minkowski, a German-American
astronomer who discovered the nebula in 1947. The PN, meanwhile, refers
to the fact that M2-9 is a planetary nebula.
The glowing and expanding shells of gas clearly visible in this image
represent the final stages of life for an old star of low to
intermediate mass. The star has not only ejected its outer layers, but
the exposed remnant core is now illuminating these layers — resulting in
a spectacular light show like the one seen here. However, the Twin Jet
Nebula is not just any planetary nebula, it is a bipolar nebula.
Ordinary planetary nebulae have one star at their centre, bipolar nebulae have two, in a binary star system.
Ordinary planetary nebulae have one star at their centre, bipolar nebulae have two, in a binary star system.
Astronomers have found that
the two stars in this pair each have around the same mass as the Sun,
ranging from 0.6 to 1.0 solar masses for the smaller star, and from 1.0
to 1.4 solar masses for its larger companion. The larger star is
approaching the end of its days and has already ejected its outer layers
of gas into space, whereas its partner is further evolved, and is a
small white dwarf.
The characteristic shape of the wings of the Twin Jet Nebula is most
likely caused by the motion of the two central stars around each other.
It is believed that a white dwarf orbits its partner star and thus the
ejected gas from the dying star is pulled into two lobes rather than
expanding as a uniform sphere.
However, astronomers are still debating whether all bipolar nebulae are
created by binary stars. Meanwhile the nebula’s wings are still growing
and, by measuring their expansion, astronomers have calculated that the
nebula was created only 1200 years ago.
Within the wings, starting from the star system and extending
horizontally outwards like veins are two faint blue patches. Although
these may seem subtle in comparison to the nebula’s rainbow colours,
these are actually violent twin jets streaming out into space, at speeds
in excess of one million kilometres per hour. This is a phenomenon that
is another consequence of the binary system at the heart of the nebula.
These jets slowly change their orientation, precessing across the lobes as they are pulled by the wayward gravity of the binary system.
The two stars at the heart of the nebula circle one another roughly
every 100 years. This rotation not only creates the wings of the
butterfly and the two jets, it also allows the white dwarf to strip gas
from its larger companion, which then forms a large disc of material
around the stars, extending out as far as 15 times the orbit of Pluto!
Even though this disc is of incredible size, it is much too small to be
seen on the image taken by Hubble.
An earlier image of the Twin Jet Nebula using data gathered by Hubble’s Wide Field Planetary Camera 2 was released in 1997. This newer version incorporates more recent observations from the telescope’s Space Telescope Imaging Spectrograph (STIS).
A version of this image was entered into the Hubble’s Hidden
Treasures image processing competition, submitted by contestant Judy
Schmidt.
Notes
The Hubble Space Telescope is a project of international cooperation between ESA and NASA.
More Information
Image credit: ESA/Hubble & NASA
Acknowledgement: Judy Schmidt
Acknowledgement: Judy Schmidt
Contacts
Mathias Jäger
ESA/Hubble, Public Information Officer
Garching bei München, Germany
Tel: +49 176 62397500
Email: mjaeger@partner.eso.org
ESA/Hubble, Public Information Officer
Garching bei München, Germany
Tel: +49 176 62397500
Email: mjaeger@partner.eso.org
Source: ESA/HUBBLE - Space Telescope
