Bubble Nebula (NGC 7635)
Ground-based Field of View and Location of the Bubble Nebula
This graphic shows the wider context of the Bubble Nebula. The National
Optical Astronomy Observatory (NOAO) image (left) by Travis Rector has
been rotated and cropped to be north-up and closer to the orientation
of the Hubble Space Telescope image (right). In addition to the inner
bubble seen in the Hubble image, the wider view shows a large cloud
complex, including two larger shells surrounding the massive star near
the center. Credit: T. Rector/University of Alaska Anchorage, H. Schweiker/WIYN and NOAO/AURA/NSF, NASA, ESA, and the Hubble Heritage Team (STScI/AURA)
Twenty-six candles grace NASA's Hubble Space Telescope's birthday cake this year, and now one giant space "balloon" will add to the festivities. Just in time for the 26th anniversary of Hubble's launch on April 24, 1990, the telescope has photographed an enormous, balloon-like bubble being blown into space by a super-hot, massive star. Astronomers trained the iconic telescope on this colorful feature, called the Bubble Nebula, or NGC 7635. The bubble is 7 light-years across — about one-and-a-half times the distance from our sun to its nearest stellar neighbor, Alpha Centauri. The Bubble Nebula lies 7,100 light-years from Earth in the constellation Cassiopeia.
For the 26th birthday of NASA's Hubble Space Telescope, astronomers
are highlighting a Hubble image of an enormous bubble being blown into
space by a super-hot, massive star. The Hubble image of the Bubble
Nebula, or NGC 7635, was chosen to mark the 26th anniversary of the
launch of Hubble into Earth orbit by the STS-31 space shuttle crew on
April 24, 1990.
"As Hubble makes its 26th revolution around our home star, the sun,
we celebrate the event with a spectacular image of a dynamic and
exciting interaction of a young star with its environment. The view of
the Bubble Nebula, crafted from Wide Field Camera 3 images, reminds us
that Hubble gives us a front-row seat to the awe-inspiring universe we
live in,” said John Grunsfeld, astronaut and associate administrator of
NASA's Science Mission Directorate at NASA Headquarters, in Washington,
D.C.
The Bubble Nebula is 7 light-years across — about one-and-a-half
times the distance from our sun to its nearest stellar neighbor, Alpha
Centauri — and resides 7,100 light-years from Earth in the
constellation Cassiopeia.
The seething star forming this nebula is 45 times more massive than
our sun. Gas on the star gets so hot that it escapes away into space as
a "stellar wind" moving at over 4 million miles per hour. This outflow
sweeps up the cold, interstellar gas in front of it, forming the outer
edge of the bubble much like a snowplow piles up snow in front of it
as it moves forward.
As the surface of the bubble's shell expands outward, it slams into
dense regions of cold gas on one side of the bubble. This asymmetry
makes the star appear dramatically off-center from the bubble, with its
location in the 10 o'clock position in the Hubble view.
Dense pillars of cool hydrogen gas laced with dust appear at the
upper left of the picture, and more "fingers" can be seen nearly
face-on, behind the translucent bubble.
The gases heated to varying temperatures emit different colors:
oxygen is hot enough to emit blue light in the bubble near the star,
while the cooler pillars are yellow from the combined light of hydrogen
and nitrogen. The pillars are similar to the iconic columns in the
"Pillars of Creation" in the Eagle Nebula. As seen with the structures
in the Eagle Nebula, the Bubble Nebula pillars are being illuminated by
the strong ultraviolet radiation from the brilliant star inside the
bubble.
The Bubble Nebula was discovered in 1787 by William Herschel, a
prominent British astronomer. It is being formed by a prototypical
Wolf-Rayet star, BD +60°2522, an extremely bright, massive, and
short-lived star that has lost most of its outer hydrogen and is now
fusing helium into heavier elements. The star is about 4 million years
old, and in 10 million to 20 million years, it will likely detonate as a
supernova.
Hubble's Wide Field Camera 3 imaged the nebula in visible light with
unprecedented clarity in February 2016. The colors correspond to blue
for oxygen, green for hydrogen, and red for nitrogen. This information
will help astronomers understand the geometry and dynamics of this
complex system.
The Bubble Nebula is one of only a handful of astronomical objects
that have been observed with several different instruments onboard
Hubble. Hubble also imaged it with the Wide Field Planetary Camera
(WFPC) in September of 1992, and with Wide Field Planetary Camera 2
(WFPC2) in April of 1999.
For more information, contact:
Felicia Chou
NASA Headquarters, Washington, D.C.
202-358-0257
felicia.chou@nasa.gov
Ann Jenkins / Ray Villard
Space Telescope Science Institute, Baltimore, Maryland
410-338-4488 / 410-338-4514
jenkins@stsci.edu / villard@stsci.edu
Zolt Levay
Space Telescope Science Institute, Baltimore, Maryland
410-338-4907
levay@stsci.edu
Source: HubbleSite
