APOD

[Moonraker]

Wow, nice shot of a colliding galaxy RR.

[Pags]

QUOTE (RushRevisited @ Nov 22 2004, 11:00 AM)

http://antwrp.gsfc.nasa.gov/apod/image/0411/ngc2207_hst.jpg Explanation: Billions of years from now, only one of these two galaxies will remain. Until then, spiral galaxies NGC 2207 and IC 2163 will slowly pull each other apart, creating tides of matter, sheets of shocked gas, lanes of dark dust, bursts of star formation, and streams of cast-away stars. Astronomers predict that NGC 2207, the larger galaxy on the left, will eventually incorporate IC 2163, the smaller galaxy on the right. In the most recent encounter that peaked 40 million years ago, the smaller galaxy is swinging around counter-clockwise, and is now slightly behind the larger galaxy. The space between stars is so vast that when galaxies collide, the stars in them usually do not collide.

This is amazing. I have a question for you.... you stated that the stars within these galaxies are most likely not to collide. Do you know what the actual event(s) are expected to be as these two galaxies continue to collide? I guess to ask it another way... What is going to happen to IC 2163 as it is overtaken?

[Moonraker]

There is so much empty space between the stars in any galaxy, it would be almost impossible for them to actually get close enough to collide with each other.

[launchpad67a]

QUOTE (paganoman @ Nov 22 2004, 11:26 AM)

This is amazing. I have a question for you.... you stated that the stars within these galaxies are most likely not to collide. Do you know what the actual event(s) are expected to be as these two galaxies continue to collide? I guess to ask it another way... What is going to happen to IC 2163 as it is overtaken?

I can answer this one. IC 2163 will be engulfed by NGC 2207, thus making a larger, more dense 2207. Gravity is the key factor here, 2207 is much larger and will pull anything and everything into it. There could be collisions of one kind or another which will just create more matter, making it even more dense.

For example: if Jupiter were closer to the earth, it's gravity would pull us right into it, making for a very impressive event...if you could see it from another planet!!

[Pags]

QUOTE (launchpad67a @ Nov 22 2004, 11:51 AM)

QUOTE (paganoman @ Nov 22 2004, 11:26 AM) This is amazing.  I have a question for you.... you stated that the stars within these galaxies are most likely not to collide.  Do you know what the actual event(s) are expected to be as these two galaxies continue to collide?  I guess to ask it another way... What is going to happen to IC 2163 as it is overtaken? I can answer this one. IC 2163 will be engulfed by NGC 2207, thus making a larger, more dense 2207. Gravity is the key factor here, 2207 is much larger and will pull anything and everything into it. There could be collisions of one kind or another which will just create more matter, making it even more dense. For example: if Jupiter were closer to the earth, it's gravity would pull us right into it, making for a very impressive event...if you could see it from another planet!! So IC 2163's 'sun' becomes just a star within NGC 2207's galaxy? The stars/planets that currently orbit to IC 2163's sun will change their orbit and their direction to NGC 2207's sun? Is this a fair guess?   I wonder what will happen to the surfaces of these planets as their rotations change over time.   KEWL

[launchpad67a]

QUOTE (paganoman @ Nov 22 2004, 12:15 PM)

So IC 2163's 'sun' becomes just a star within NGC 2207's galaxy? The stars/planets that currently orbit to IC 2163's sun will change their orbit and their direction to NGC 2207's sun? Is this a fair guess? I wonder what will happen to the surfaces of these planets as their rotations change over time. KEWL

Well you must understand that a galaxy doesn't have a single 'sun', like our 'Solar System'. I think your referring to the center of the galaxy, where it's very bright and dense. This area is filled with millions of suns (stars).

Our Solar System has a single sun and 9 planets. Our 'Milky Way Galaxy', which our solar system resides in, has millions of suns!!!

There are more stars in the sky, then there are grains of sand on All the beaches in the world....thats a lot of suns/stars. It's enough to make your brain melt

[RushRevisited]

http://antwrp.gsfc.nasa.gov/apod/image/0204/etacarinae3_hst.jpg

 

Explanation: Eta Carinae may be about to explode. But no one knows when - it may be next year, it may be one million years from now. Eta Carinae's mass - about 100 times greater than our Sun - makes it an excellent candidate for a full blown supernova. Historical records do show that about 150 years ago Eta Carinae underwent an unusual outburst that made it one of the brightest stars in the southern sky. Eta Carinae, in the Keyhole Nebula, is the only star currently thought to emit natural LASER light. This image, taken in 1996, resulted from sophisticated image-processing procedures designed to bring out new details in the unusual nebula that surrounds this rogue star. Now clearly visible are two distinct lobes, a hot central region, and strange radial streaks. The lobes are filled with lanes of gas and dust which absorb the blue and ultraviolet light emitted near the center. The streaks remain unexplained. Will these clues tell us how the nebula was formed? Will they better indicate when Eta Carinae will explode?

[Jack Aubrey]

QUOTE (RushRevisited @ Nov 29 2004, 11:24 AM)

http://antwrp.gsfc.nasa.gov/apod/image/0204/etacarinae3_hst.jpg Explanation: Eta Carinae may be about to explode. But no one knows when - it may be next year, it may be one million years from now. Eta Carinae's mass - about 100 times greater than our Sun - makes it an excellent candidate for a full blown supernova. Historical records do show that about 150 years ago Eta Carinae underwent an unusual outburst that made it one of the brightest stars in the southern sky. Eta Carinae, in the Keyhole Nebula, is the only star currently thought to emit natural LASER light. This image, taken in 1996, resulted from sophisticated image-processing procedures designed to bring out new details in the unusual nebula that surrounds this rogue star. Now clearly visible are two distinct lobes, a hot central region, and strange radial streaks. The lobes are filled with lanes of gas and dust which absorb the blue and ultraviolet light emitted near the center. The streaks remain unexplained. Will these clues tell us how the nebula was formed? Will they better indicate when Eta Carinae will explode?

OK, now that's just breathtaking.

 

[Phoenix]

[RushRevisited]

http://antwrp.gsfc.nasa.gov/apod/image/0412/lakeeffect_seawifs.jpg

 

Explanation: What are those strange clouds stretching out from these lakes? The clouds are caused by cold air moving over a warm water and result in bands of lake-effect snow. The rising bands of moistened, warmed air that drop lake-effect snow alternate with clear bands of falling cold air. During a winter, such bands can create hundreds of centimeters of snow more than upwind areas only a hundred kilometers away. During this lake-effect snowfall of 2000 December 5, practically all of the state of Michigan, USA got covered. A cold southeasterly wind over Great Lakes Superior and Michigan created the unusual clouds. The above image was taken with NASA's SeaWiFS satellite.

[The Notorious B.S.G.]

WOW! Boy, do I miss my home state Mich-i-gan! But not THAT sort of weather. Cool pic!

[RushRevisited]

http://antwrp.gsfc.nasa.gov/apod/image/0412/helix_hst.jpg

 

 

Explanation: How did a star create the Helix nebula? The shapes of planetary nebula like the Helix are important because they likely hold clues to how stars like the Sun end their lives. Recent observations by the orbiting Hubble Space Telescope and the 4-meter Blanco Telescope in Chile, however, have shown the Helix is not really a simple helix. Rather, it incorporates two nearly perpendicular disks as well as arcs, shocks, and even features not well understood. Even so, many strikingly geometric symmetries remain. How a single Sun-like star created such beautiful yet geometric complexity is a topic of research. The Helix Nebula is the nearest planetary nebula to Earth, lies only about 700 light years away toward the constellation of Aquarius, and spans about 3 light-years.

[rickyrob]

QUOTE (RushRevisited @ Sep 8 2004, 09:10 AM)

http://antwrp.gsfc.nasa.gov/apod/image/0409/bhtorus_esa_big.jpg Explanation: Why do some black hole surroundings appear brighter than others? In the centers of active galaxies, supermassive black holes at least thousands of times the mass of our Sun dominate. Many, called Seyfert Type I, are very bright in visible light. Others, called Seyfert Type II, are rather dim. The difference might be caused by some black holes accreting much more matter than others. Alternatively, the black holes in the center of Seyfert Type II galaxies might be obscured by a surrounding torus. To help choose between these competing hypotheses, the nearby Seyfert II galaxy NGC 4388 has been observed in X-ray light recently by many recent Earth-orbiting X-ray observatories, including CGRO, SIGMA, BeppoSAX, INTEGRAL, Chandra, and XMM-Newton. Recent data from INTEGRAL and XMM-Newton have found that the X-ray flux in some X-ray colors varies rapidly, while flux in other X-ray colors is quite steady. The constant flux and apparent absorption of very specific X-ray colors by cool iron together give evidence that the central black hole in NGC 4388 is seen through a thick torus composed of molecular gas and dust.

RR...this is a BEAST! I've never seen this picture before....it puts Cygnus X-1 to shame! although Cygnus is drawing matter from a 'partner'.

 

Yes, the reason black holes generally don't look black is because the 'balck hole' itself it far too small to actually be seen. Only past the event horizon can light not escape, and this can vary in size from thousands of miles to just a few miles - very small on astronomical scales.

 

I've only just picked up this thread, its cool - I love astronomy

[Alsgalpal]

Wow, I totally forgot about this thread... I have a stupid question, is that Eta Carinae close to us??? Will it affect us once it decides to 'go'??

 

 

 

In case you didnt notice, AGP is a worrywart...

[rickyrob]

QUOTE (Alsgalpal @ Dec 29 2004, 10:25 AM)

Wow, I totally forgot about this thread... I have a stupid question, is that Eta Carinae close to us??? Will it affect us once it decides to 'go'?? In case you didnt notice, AGP is a worrywart...

AGP, I wouldn't worry too much about Eta Carinae, its Andromeda you really need to worry about. Our Milky Way Galaxy is apparently on a collision course with it.

[ES-335]

QUOTE (RushRevisited @ Nov 30 2004, 11:07 AM)

http://antwrp.gsfc.nasa.gov/apod/image/0412/lakeeffect_seawifs.jpg Explanation: What are those strange clouds stretching out from these lakes? The clouds are caused by cold air moving over a warm water and result in bands of lake-effect snow. The rising bands of moistened, warmed air that drop lake-effect snow alternate with clear bands of falling cold air. During a winter, such bands can create hundreds of centimeters of snow more than upwind areas only a hundred kilometers away. During this lake-effect snowfall of 2000 December 5, practically all of the state of Michigan, USA got covered. A cold southeasterly wind over Great Lakes Superior and Michigan created the unusual clouds. The above image was taken with NASA's SeaWiFS satellite.

Looks like a bad comb over

 

 

[rickyrob]

Looks can be deceiving, especially when it comes to celestial objects like galaxies and nebulas. These objects are so far away that astronomers cannot see their three-dimensional structure. The Helix Nebula, for example, resembles a doughnut in colorful images. Earlier images of this complex object — the gaseous envelope ejected by a dying, sun-like star — did not allow astronomers to precisely interpret its structure. One possible interpretation was that the Helix's form resembled a snake-like coil. Evidence suggests that the Helix consists of two gaseous disks nearly perpendicular to each other.

 

"Our new observations show that the previous model of the Helix was much too simple," O'Dell said. "About a year ago, we believed the Helix was a bagel shape, filled in the middle. Now we see that this filled bagel is just the inside of the object. A much larger disk, resembling a wide, flat ring, surrounds the filled bagel. This disk is oriented almost perpendicular to the bagel. The larger disk is brighter on one side because it is slamming into interstellar material as the entire nebula moves through space, like a boat plowing through water. The encounter compresses gas, making that region glow brighter. But we still don't understand how you get such a shape. If we could explain how this shape was created, then we could explain the late stages of the most common form of collapsing stars."

 

http://imgsrc.hubblesite.org/hu/db/2004/32/images/a/formats/web_print.jpg

 

[RushRevisited]

http://antwrp.gsfc.nasa.gov/apod/image/0501/m45_russell.jpg

 

Explanation: Perhaps the most famous star cluster on the sky, the Pleiades can be seen without binoculars from even the depths of a light-polluted city. Also known as the Seven Sisters and M45, the Pleiades is one of the brightest and closest open clusters. The Pleiades contains over 3000 stars, is about 400 light years away, and only 13 light years across. Quite evident in the above photograph are the blue reflection nebulae that surround the brighter cluster stars. Low mass, faint, brown dwarfs have also been found in the Pleiades. (Editors' note: The prominent diffraction spikes are caused by the telescope itself and may be either distracting or provide aesthetic enhancement, depending on your point of view.)

[Phoenix]

QUOTE (RushRevisited @ Jan 3 2005, 09:15 AM)

Explanation: Perhaps the most famous star cluster on the sky, the Pleiades can be seen without binoculars from even the depths of a light-polluted city. Also known as the Seven Sisters and M45, the Pleiades is one of the brightest and closest open clusters. The Pleiades contains over 3000 stars, is about 400 light years away, and only 13 light years across. Quite evident in the above photograph are the blue reflection nebulae that surround the brighter cluster stars. Low mass, faint, brown dwarfs have also been found in the Pleiades. (Editors' note: The prominent diffraction spikes are caused by the telescope itself and may be either distracting or provide aesthetic enhancement, depending on your point of view.)

A facinating object.

Did some one know that the Maya allready counted more than 40 single stars in that cluster.

Everytime I look to the sky and saw them, I take a rest and watch for a minute or so.

[dr.nobraino]

cool stuff. . . .thought I saw the Rocinante their for a sec. . .

[RushRevisited]

http://antwrp.gsfc.nasa.gov/apod/image/0501/orionNeb_ukirt_c30.jpg

 

Explanation: At the edge of a dense molecular cloud, filaments of gas, cosmic dust, and a multitude of young stars beckon in this penetrating image of the Orion Nebula. Alluring structures in the well-known star forming region are revealed here in infrared light as viewed by a new Hawaiian eye - WFCAM - a powerful wide field camera commissioned at the United Kingdom Infrared Telescope (UKIRT) on Mauna Kea. Only a fraction of WFCAM's full field, this picture covers about 11 light-years at the 1,500 light-year distance of the nebula. In the image, otherwise invisible infrared light has been mapped into visible colors. Red represents narrow-band infrared emission from hydrogen molecules at a wavelength of 2.12 microns, green is emission at 2.2 microns, and blue is emission at 1.25 microns. Visible light has a wavelength of about 0.5 microns (micrometers).

[Jack Aubrey]

Cool! I'd forgotten about thtis thread. Thanks for bringing back, RR!

[RushRevisited]

http://antwrp.gsfc.nasa.gov/apod/image/0412/rosette_crawford.jpg

 

Explanation: What creates the cosmic dust sculptures in the Rosette Nebula? Noted for the common beauty of its overall shape, parts of the Rosette Nebula, also known as NGC 2244, show beauty even when viewed up close. Visible above are globules of dark dust and gas that are slowly being eroded away by the energetic light and winds by nearby massive stars. Left alone long enough, the molecular-cloud globules would likely form stars and planets. The above image was taken in very specific colors of Silicon (shaded red), Hydrogen (green), and Oxygen (blue). The Rosette Nebula spans about 50 light-years across, lies about 4,500 light-years away, and can be seen with a small telescope towards the constellation of Monoceros.

[afansince74]

I LOVE THIS THREAD! RR, you're awesome man!

[RushRevisited]

QUOTE (afansince74 @ Jan 10 2005, 10:18 PM)

I LOVE THIS THREAD! RR, you're awesome man!

All compliments of Nasa and the Astronomy Picture of the Day!