Orion Nebula M42, Hubble images (2)

Orion Nebula M42 Hubble pictures:

Panorama with Trapezium,

protoplanetary systems,

edge-on disk.

Other HST pictures of M42:

Pre-repair,

proplyd discovery,

January 1997,

May 1997 (OMC 1 with NIC).

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Crucible of Creation

Panoramic Hubble mosaic zooms in

on Maelstrom of star birth

This color panorama of the center the Orion nebula is one

of the largest pictures ever assembled from individual images taken

with NASA’s Hubble Space Telescope. Seamlessly composited

from a mosaic of 15 separate fields, it covers an area about

five percent that covered by the full Moon.

The seemingly infinite tapestry of rich detail revealed by Hubble shows

a churning turbulent star factory set within a maelstrom of flowing,

luminescent gas. Though this 2.5 light-years wide view is still a

small portion of the entire nebula, it includes almost all of the light

from the bright glowing clouds of gas and a star cluster associated

with the nebula. Hubble reveals details as small as 4.1 billion miles

across (less than the distance of Neptune from the Sun).

Hubble Space Telescope observing time was devoted to making this

panorama because the nebula is a vast laboratory for studying the

processes which gave birth to our own Sun and solar system 4.5 billion

years ago. Many of the nebula’s details can’t be captured in a single

picture – any more than one snapshot of the Grand Canyon yields clues

to its formation and history. Like the Grand Canyon, the Orion nebula

has a dramatic surface topography — of glowing gasses instead of rock

— with peaks, valleys and walls. They are illuminated and heated by

a torrent of energetic ultraviolet light from its four hottest and most

massive stars, called the Trapezium, which lie near the center of the

image.

In addition to the Trapezium, this stellar cavern contains 700 hundred

other young stars at various stages of formation. High-speed jets of

hot gas spewed by some of the infant stars send supersonic shock waves

tearing into the nebula at 100,000 miles per hour. These shock waves

appear as thin curved loops, sometimes with bright knots on their end

(the brightest examples are near the bright star at the lower left).

The mosaic reveals at least 153 glowing protoplanetary disks (first

discovered with the Hubble in 1992, and dubbed “proplyds”) that are

believed to be embryonic solar systems that will eventually form

planets. (Our solar system has long been considered the relic of just

such a disk that formed around the newborn Sun). The abundance of such

objects in the Orion nebula strengthens the argument that planet

formation is a common occurrence in the universe. The proplyds that

are closest to the Trapezium stars (image center) are shedding some of

their gas and dust. The pressure of starlight from the hottest stars

forms “tails” which act like wind vanes pointing away from the

Trapezium. These tails result from the light from the star pushing the

dust and gas away from the outside layers of the proplyds. In addition

to the luminescent proplyds, seven disks are silhouetted against the

bright background of the nebula. These dark objects allow Hubble

astronomers to estimate the masses of the disks as at least 0.1 to 730

times the mass of our Earth.

Located 1,500 light-years away, along our spiral arm of the Milky Way,

the Orion nebula is located in the middle of the sword region of the

constellation Orion the Hunter, which dominates the early winter

evening sky, at northern latitudes. The stars have formed from

collapsing clouds of interstellar gas within the last million years.

The most massive clouds have formed the brightest stars near the center

and these are so hot that they illuminate the gas left behind after the

period of star formation was complete. The more numerous faint stars

are still in the process of collapsing under their own gravity, but

have become hot enough in their centers to be self luminous bodies.

Technical information: To create this color mosaic, 45 separate images

of the Orion nebula were taken in blue, green and red between January

1994 and March 1995. Light emitted by oxygen is shown as blue,

hydrogen emission is shown as green, and nitrogen emission as red

light. The overall color balance is close to that which an observer

living near the Orion nebula would see. The irregular borders produced

by the HST images have been smoothed out by the addition of images from

the European Southern Observatory in Chile obtained by Bo Reipurth and

John Bally, these being about 2% of the area shown here and lying at

the top left corner.

Credit: C.R. O’Dell (Rice University), and NASA

• Original press release
  

  Planetary Systems in the Making

  

  These are HST images of four newly discovered

  protoplanetary disks around young stars in the Orion nebula, located

  1,500 light-years away. Gas and dust disks, long suspected by

  astronomers to be an early stage of planetary formation, can be

  directly seen in visible light by Hubble.

  Disks around young stars (also known as circumstellar or protoplanetary

  disks) are thought to be made up of 99% gas and 1% dust. Even that

  small amount of dust is enough to make the disks opaque and dark at

  visible wavelengths. The dark disks are seen in these images because

  they are silhouetted against the bright backdrop of the hot gas of the

  Orion nebula.

  The red glow in the center of each disk is a young, newly formed star,

  roughly one million years old (compared to the 4.5 billion year age of

  the Sun). The stars range in mass from 30% to 150% of the mass of our

  own Sun. As they evolve, the disks may go on to form planetary systems

  like our own. While only a handful of these dark silhouette disks have

  been discovered so far, they seem to belong to a much larger family of

  similar objects, and current indications are that protoplanetary disks

  are common in the Orion nebula.

  Mark McCaughrean of the Max-Planck-Institute for Astronomy, Heidelberg,

  Germany, and his collaborator C. Robert O’Dell from Rice University,

  Houston, Texas, spotted the new disks in large-scale survey images of

  the Orion nebula that O’Dell had taken with Hubble between January 1994

  and March 1995. A detailed study of the disk images has been submitted

  for publication to the Astronomical Journal.

  Each image is 167 billion miles, or 257 billion kilometers across (30

  times the diameter of our own solar system). The disks range in size

  from two to eight times the diameter of our solar system. The

  researchers explain the different circular or elliptical shapes as

  being due to the fact that each disk is tilted toward Earth by

  different degrees.

  Each picture is a composite of three images taken with Hubble’s Wide

  Field and Planetary Camera 2, through narrow-band filters which admit

  the light of emission lines of ionized oxygen (represented here by

  blue), hydrogen (green), and nitrogen (red). The hot gas of the

  background Orion nebula emits strongly at each of these wavelengths,

  providing a strong backdrop for the disks to be silhouetted against.

  In each case, the central star is also clearly visible.

  Credit: Mark McCaughrean (Max-Planck-Institute for Astronomy),

  C. Robert O’Dell (Rice University), and NASA

• Original Press Release
  

  Edge-on protoplanetary disk in the Orion nebula

  

  Resembling an interstellar Frisbee, this is a disk of dust seen edge-on

  around a newborn star in the Orion nebula, located 1,500 light-years

  away. Because the disk is edge-on, the star is largely hidden inside,

  in this striking Hubble Space Telescope picture. The disk may be an

  embryonic planetary system in the making. Our solar system probably

  formed out of just such a disk 4.5 billion years ago. At 17 times the

  diameter of our own solar system, this disk is the largest of several

  recently discovered in the Orion nebula.

  The left image is a three-color composite, taken in blue, green, and

  red emission lines from glowing gas in the nebula. The right image was

  taken through a different filter, which blocks any bright spectral

  emission lines from the nebula, and hence the disk itself is less

  distinctly silhouetted against the background. However, clearly

  visible in this image are nebulosities above and below the plane of the

  disk; these betray the presence of the otherwise invisible central

  star, which cannot be seen directly due to dust in the edge-on disk.

  The images were taken between January 1994 and March 1995, and a study

  of their characteristics has been submitted for publication to the

  Astronomical Journal.

  Credit: Mark McCaughrean (Max-Planck-Institute for Astronomy),

  C. Robert O’Dell (Rice University), and NASA

• Original Press Release

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  Hartmut Frommert

  ([email protected])

  Christine Kronberg

  ([email protected])

  

  

  

  

  

  Last Modification: 24 May 1998, 15:55 MET