A Look at Space: Part 3: Nebulae

Nebula : A diffuse mass of interstellar dust or gas or both, visible as luminous patches or areas of darkness depending on the way the mass absorbs or reflects incident radiation.
They possess the raw material for the formation of stars.

There are many types of Nebulae, as described here: home.cwru.edu...
Namely,
Emission, Reflection, Dark, Planetary, and Supernova-remnants.

The Crab Nebula : A Supernova Remnant
external image
Source: antwrp.gsfc.nasa.gov...

Pictures of Nebulae are breath-taking and colorful. Feel free to post pictures/links of different nebulae that you find interesting or comments on different pictures. Please, if possible, give their names and a brief description.
Thanks in advance

--------
Also Check out:
> A Look at Space: Part 1: The Weirdest and The Mysterious
> A Look at Space: Part 2: Galaxies

[edit on 8/9/2004 by jp1111]

More:
heritage.stsci.edu...

Jesus,,,i just realize now that i have post nebulas in the galaxies topic...my fault, sorry mate, i will try to fix that.~


heritage.stsci.edu...

heritage.stsci.edu...

heritage.stsci.edu...



*edited to putt the right objects

[edit on 8-8-2004 by kangaxx]

[edit on 8-8-2004 by kangaxx]

I have to stick with the ring nebula... simple, yet beautiful.

Thanks for the pictures everybody!

For viewers' convenience, here are some picture-descriptions that I found for the ones posted above:

Thackeray's Globules in IC 2944: The globules are the dark nebula type and the background (IC 2944) is a bright emission nebula.
Description: Link 1: www.spaceref.ca...
"The globules appear to be heavily fractured, as if major forces were tearing them apart. When radio astronomers observed the faint hiss of molecules within the globules, they realized that the globules are actually in constant, churning motion, moving supersonically among each other."
Description: Link 2: antwrp.gsfc.nasa.gov...
"These and similar dark globules known to be associated with other star forming regions may ultimately be dissipated by their hostile environment -- like cosmic lumps of butter in a hot frying pan."

IC 418 : Also known as The Spirograph Nebula: A Planetary Nebula.
Description: antwrp.gsfc.nasa.gov...
"What is creating the strange texture of IC 418? Dubbed the Spirograph Nebula for its resemblance to drawings from a cyclical drawing tool, planetary nebula IC 418 shows patterns that are not well understood. Perhaps they are related to chaotic winds from the variable central star, which changes brightness unpredictably in just a few hours."

NGC 6751 : A Planetary Nebula.
Description: Link 1: grin.hq.nasa.gov...
"The nebula shows several remarkable and poorly understood features. Blue regions mark the hottest glowing gas, which forms a roughly circular ring around the central stellar remnant. Orange and red show the locations of cooler gas. The cool gas tends to lie in long streamers pointing away from the central star, and in a surrounding, tattered-looking ring at the outer edge of the nebula. The origin of these cooler clouds within the nebula is still uncertain, but the streamers are clear evidence that their shapes are affected by radiation and stellar winds from the hot star at the center."
Description: antwrp.gsfc.nasa.gov...
"Winds and radiation from the intensely hot central star (140,000 degrees Celsius) have apparently created the nebula's streamer-like features. The nebula's actual diameter is approximately 0.8 light-years or about 600 times the size of our solar system. NGC 6751 is 6,500 light-years distant in the constellation Aquila."

The Keyhole Nebula : An Emission Nebula. Largely known as The Carina Nebula, NGC 3372.
Description: Link: hubblesite.org...
"When 19th century astronomer Sir John Herschel spied a swirling cloud of gas with a hole punched through it, he dubbed it the Keyhole Nebula. Now the Hubble telescope has taken a peek at this region, and the resulting image reveals previously unseen details of the Keyhole's mysterious, complex structure. The Keyhole is part of a larger region called the Carina Nebula (NGC 3372), about 8,000 light-years from Earth."
Further, I also found that "This[the one on the top-left] dense cloud of gas and dust is being deleted. Likely, within a few million years, the intense light from bright stars will have boiled it away completely." Source Link: antwrp.gsfc.nasa.gov...

The Ring Nebula : M57: A Planetary Nebula.
Description: Link: www.seds.org...
"There are even indications from investigations of deep observations such as George Jacoby's deep photos obtained at Kitt Peak National Observatory that the overall shape might be more that of a cylinder viewed along the direction of the axis than that of a ring, i.e., we are looking down a tunnel of gas ejected by a star at the end of its nuclear-burning life."
Description: Link: antwrp.gsfc.nasa.gov...
"Except for the rings of Saturn, the Ring Nebula (M57) is probably the most famous celestial band. This planetary nebula's simple, graceful appearance is thought to be due to perspective -- our view from planet Earth looking straight into what is actually a barrel-shaped cloud of gas shrugged off by a dying central star."

I'm posting a few soon...

looking at this thread and the two other made by jp1111 really makes me want to explore space. dammit, why couldn't i be born later into the future where space travel is common like driving a car

Originally posted by 2009
looking at this thread and the two other made by jp1111 really makes me want to explore space. dammit, why couldn't i be born later into the future where space travel is common like driving a car

That's what I think sometimes, however...

Not to disappoint anybody here or anything, but when thinking of space travel to these beautiful stellar objects with the hopes of seeing the same colors and shapes, one has to consider the limited nature of human vision also. If you were to travel to any of these "colorful" objects in the universe, as much as its magnification, you wouldn't see the same as in the pictures.
More explained here: hubblesite.org...
And discussed here: www.photo.net...

Now, someone might question, what's the point of looking at pictures of stuff that wouldn't be the same for human eyes in reality? We should rather think of hubble and other space-telescopes as our "powerful eyes" that enable us to view the most amazing stuff in the universe, which wouldn't be always possible with a human eye!

We can't see it, but that doesn't mean that it doesn't exist!
Thanks hubble and other space telescopes for letting us "see" the invisible




[edit on 8/9/2004 by jp1111]

A few pictures here:
We will have a similar planetary nebula at the end of our Sun's life!

A Seemingly Square Nebula : IC 4406 : A Planetary Nebula
(Note: It was also posted by pushkin- Post Number: 712322 in Part1)
external image
Source & Description: antwrp.gsfc.nasa.gov...
"How can a round star make a square nebula? This conundrum comes to light when studying planetary nebulae like IC 4406. Evidence indicates that IC 4406 is likely a hollow cylinder, with its square appearance the result of our vantage point in viewing the cylinder from the side. Were IC 4406 viewed from the top, it would likely look similar to the Ring Nebula."
Another picture of the same: www.astro.psu.edu...


The Cat's Eye Nebula : NGC 6543 : A Planetary Nebula
external image
Source & Description: antwrp.gsfc.nasa.gov...
"Three thousand light-years away, a dying star throws off shells of glowing gas. This image from the Hubble Space Telescope reveals the Cat's Eye Nebula to be one of the most complex planetary nebulae known. In fact, the features seen in the Cat's Eye are so complex that astronomers suspect the bright central object may actually be a binary star system."
Description: hubblesite.org...
"Hubble reveals surprisingly intricate structures including concentric gas shells, jets of high-speed gas, and unusual shock-induced knots of gas. Estimated to be 1,000 years old, the nebula is a visual "fossil record" of the dynamics and late evolution of a dying star."
Description & Picture: chandra.harvard.edu...
"Chandra Reveals The X-Ray Glint In The Cat's Eye"
Description & Picture: antwrp.gsfc.nasa.gov...
"Halo of the Cat's Eye"

The Eskimo Nebula : NGC 2392 : A Planetary Nebula
external image
Source & Description: antwrp.gsfc.nasa.gov...
"From the ground, NGC 2392 resembles a person's head surrounded by a parka hood...From space, the nebula displays gas clouds so complex they are not fully understood...The inner filaments visible above are being ejected by strong wind of particles from the central star. The outer disk contains unusual light-year long orange filaments."

The Eight-burst Nebula : NGC 3132 : A Planetary Nebula
external image
Source & Description: antwrp.gsfc.nasa.gov...
"It's the dim star, not the bright one, near the center of NGC 3132 that created this odd but beautiful planetary nebula...Although photographed to explore unusual symmetries, it's the asymmetries that help make NGC 3132 so intriguing. Neither the unusual shape of the surrounding cooler shell nor the structure and placements of the cool filamentary dust lanes running across NGC 3132 are well understood."
Description: hubblesite.org...

The Little Ghost Nebula : NGC 6369 : A Planetary Nebula
external image
Source & Description: antwrp.gsfc.nasa.gov...
"Surprisingly complex details and structures of NGC 6369 are revealed in this delightful color image composed from Hubble Space Telescope data. The nebula's main ring structure is about a light-year across and the glow from ionized oxygen, hydrogen, and nitrogen atoms are colored blue, green, and red respectively. Over 2,000 light-years away, the Little Ghost Nebula offers a glimpse of the fate of our Sun, which should produce its own pretty planetary nebula only about 5 billion years from now."
Description: www.space.com...
"The nebula, officially called NGC 6369, appears in most telescopes as a small, ghostly cloud surrounding a faint, dying central star. It resides the constellation Ophiuchus, between 2,000 and 5,000 light-years away."

The Helix Nebula : NGC 7293 : A Planetary Nebula
external image
Source & Description: antwrp.gsfc.nasa.gov...
"The Helix Nebula is the closest example of a planetary nebula created at the end of the life of a Sun-like star...The Helix Nebula, given a technical designation of NGC 7293, lies about 650 light-years away towards the constellation of Aquarius and spans about 2.5 light-years."
Description: hubblesite.org...
Description & Picture: hubblesite.org...
"Hubble captured thousands of these knots from a doomed star in the Helix nebula, the closest planetary nebula to Earth at 450 light-years away in the constellation Aquarius."

The Hour-glass Nebula : MyCn18 : A Planetary Nebula
external image
Source & Description: antwrp.gsfc.nasa.gov...
"Here, delicate rings of colorful glowing gas (nitrogen-red, hydrogen-green, and oxygen-blue) outline the tenuous walls of the "hourglass". The unprecedented sharpness of the HST images has revealed surprising details of the nebula ejection process and may help resolve the outstanding mystery of the variety of complex shapes and symmetries of planetary nebulae."
Description: hubblesite.org...
"According to one theory for the formation of planetary nebulae, the hourglass shape is produced by the expansion of a fast stellar wind within a slowly expanding cloud which is more dense near its equator than near its poles...Hubble has also revealed other features in MyCn18 which are completely new and unexpected. For example, there is a pair of intersecting elliptical rings in the central region which appear to be the rims of a smaller hourglass. There are the intricate patterns of the etchings on the hourglass walls."

[edit on 8/9/2004 by jp1111]

Originally posted by jp1111
... but when thinking of space travel to these beautiful stellar objects with the hopes of seeing the same colors and shapes, one has to consider the limited nature of human vision also.

Absolutely TRUE!!

Human vision has a certain field of frequencies, and below and/or above them we can't retain visual data, In other words...we can't see!

To those that believe that we can reach at higher levels of our conscious mind, it is certain that the higher the vibration, the higher the specter, thus ... more colours to add to our collection

Originally posted by HARAK
Absolutely TRUE!!

Human vision has a certain field of frequencies, and below and/or above them we can't retain visual data, In other words...we can't see!

To those that believe that we can reach at higher levels of our conscious mind, it is certain that the higher the vibration, the higher the specter, thus ... more colours to add to our collection

so you can modify you retina and brain?

Originally posted by DarkSide

Originally posted by HARAK
Absolutely TRUE!!

Human vision has a certain field of frequencies, and below and/or above them we can't retain visual data, In other words...we can't see!

To those that believe that we can reach at higher levels of our conscious mind, it is certain that the higher the vibration, the higher the specter, thus ... more colours to add to our collection

so you can modify you retina and brain?

No but those who smoke can quit and it will significantly increase your night vision which will make naked eye sightings of quite a few deep space objects possible under a properly dark sky.

Originally posted by DarkSide

so you can modify you retina and brain?

No, i can�t. Can you???

Originally posted by groingrinder
No but those who smoke can quit and it will significantly increase your night vision which will make naked eye sightings of quite a few deep space objects possible under a properly dark sky.

Thanks groingrinder!

Horsehead Nebula


The sky is strange near the Chamaeleon I complex of bright nebulas and hot stars in the constellation of the same name, close to the southern celestial pole(ESO's Very Large Telescope in Chile)


The Dumbbell Nebula is about 1,200 light-years away. It's packed with rarified gas ejected by the hot central star (visible on this photo). The gas is now lit by intense ultraviolet radiation from this star.


Bright enough to be seen with the naked eye to keen observers, the Orion nebula is a few tens of light-years' wide complex of gas and dust, illuminated by several massive and hot stars at its core, the famous Trapezium stars.



ref: space.com

Thanks pushkin for providing descriptions to your pictures, I don't have to do much work now!

A few more...

A Close-up of Cone Nebula : part of NGC 2264 : An Emission Nebula
external image
Description & Source: antwrp.gsfc.nasa.gov...
"Cones, pillars, and majestic flowing shapes abound in stellar nurseries where natal clouds of gas and dust are buffeted by energetic winds from newborn stars...While the Cone Nebula, about 2,500 light-years away in Monoceros, is around 7 light-years long, the region pictured here surrounding the cone's blunted head is a mere 2.5 light-years across."
Description: www.skyhound.com...
Distant view: Description & Picture: antwrp.gsfc.nasa.gov...

Lagoon Nebula : M8 : An Emission Nebula
external image
Source: antwrp.gsfc.nasa.gov...
external image
Source: antwrp.gsfc.nasa.gov...
external image
Source & Description: antwrp.gsfc.nasa.gov...
"The awesome spectacle of starbirth produces extreme stellar winds and intense energetic starlight -- bombarding dusty molecular clouds inside the Lagoon Nebula (M8). At least two long funnel shaped clouds, each roughly half a light-year long, have apparently been formed by this activity. They extend from the upper left of this close-up of the bright area of the Lagoon known as 'the Hour Glass'. Are these interstellar funnel clouds actually swirling, twisting analogs to Earthly tornados? It's possible. As energy from nearby young hot stars, like the one at lower right, pours into the cool dust and gas, large temperature differences in adjoining regions can be created generating shearing winds."

[edit on 8/10/2004 by jp1111]

[edit on 11-8-2004 by pushkin]

Nice pictures again, pushkin:
Here, I found descriptions as usual! The second one took some time to find!

First picture:
When Cosmic Winds Collide : LL Orionis in the Great Orion Nebula
Description: antwrp.gsfc.nasa.gov...
"This arcing, graceful structure is actually a bow shock about half a light-year across, created as the wind from young star LL Orionis collides with the Orion Nebula flow. Adrift in Orion's stellar nursery and still in its formative years, variable star LL Orionis produces a wind more energetic than the wind from our own middle-aged sun."

Second picture:
Elephant Trunk Nebula : part of IC 1396: A Dark Globule in an Emission Nebula
Description: antwrp.gsfc.nasa.gov...

Third picture:
Sharpless 140 : An Emission Nebula
Description: antwrp.gsfc.nasa.gov...
"Three young, massive stars will eventually emerge from this natal cloud of dust and gas, but their presence is already revealed in this false-color image from the Spitzer Space Telescope. The picture offers a penetrating infrared view of an emission nebula cataloged as Sharpless 140 which lies about 3,000 light-years away toward the constellation Cepheus."




[edit on 8/11/2004 by jp1111]

Antares and Rho Ophiuchi : Really colorful! ...can't post the picture, its copyrighted, but here is the link: antwrp.gsfc.nasa.gov...
"Why is the sky near Antares and Rho Ophiuchi so colorful? The colors result from a mixture of objects and processes. Fine dust illuminated from the front by starlight produces blue reflection nebulae. Gaseous clouds whose atoms are excited by ultraviolet starlight produce reddish emission nebulae. Backlit dust clouds block starlight and so appear dark. Antares, a red supergiant and one of the brighter stars in the night sky, lights up the yellow-red clouds on the upper left. Rho Ophiuchi lies at the center of the blue nebula on the right. The distant globular cluster M4 is visible just below Antares, and to the left of the red cloud engulfing Sigma Scorpii. These star clouds are even more colorful than humans can see, emitting light across the electromagnetic spectrum."

Reflection Nebula in Orion : NGC 1999 : A Dark Globule in a Reflection Nebula
external image
Description & Source: antwrp.gsfc.nasa.gov...
"A dusty bright nebula contrasts dramatically with a dusty dark nebula in this Hubble Space Telescope image recorded shortly after December's orbital servicing mission. The nebula, cataloged as NGC 1999, is a reflection nebula, which shines by reflecting light from a nearby star. Unlike emission nebulae, whose reddish glow comes from excited atoms of gas, reflection nebulae have a bluish cast as their interstellar dust grains preferentially reflect blue starlight...Extending right of center, the ominous dark nebula is actually a condensation of cold molecular gas and dust so thick and dense that it blocks light. From our perspective it lies in front of the bright nebula, silhouetted against the ghostly nebular glow. New stars will likely form within the dark cloud, called a Bok globule, as self-gravity continues to compress its dense gas and dust. Reflection nebula NGC 1999 lies about 1500 light-years away in the constellation Orion, just south of Orion's well known emission nebula, M42."

Reflecting Merope : IC 349: A Reflection Nebula
external image
Description & Source: antwrp.gsfc.nasa.gov...
"In the past 100,000 years, however, part of the cloud has by chance moved so close to the star - only 3500 times the Earth-Sun distance - that the star's light affects the cloud's dust in an unusual manner. Pressure of the star's light significantly repels the dust in the reflection nebula with smaller dust particles being repelled more strongly. Eventually parts of the dust cloud have become stratified and point toward Merope, with the closest particles being the most massive and so the least affected by the radiation pressure. A longer-term result is the general destruction of the dust by the energetic starlight. It is not known whether the cloud will survive this encounter."

[edit on 8/11/2004 by jp1111]

These are absolutely incredible. I love looking at this stuff.

Originally posted by TheHeggy
These are absolutely incredible. I love looking at this stuff.

I know. Many people have not seen a lot of these pictures from space. That's why I'm trying to find the most interesting and beautiful pictures to post them in these threads so that people can appreciate the amazing universe!