APOD: Hydrogen in M51 (2010 Jun 11)

[APOD Robot]

Hydrogen in M51

Explanation: Perhaps the original spiral nebula, M51 is a large galaxy, over 60,000 light-years across, with a readily apparent spiral structure. Also cataloged as NGC 5194, M51 is a part of a well-known interacting galaxy pair, its spiral arms and dust lanes clearly sweeping in front of companion galaxy NGC 5195 (top). This dramatically processed color composite combines M51 image data from the Calar Alto Observatory's 1.2 meter telescope. The data include long exposures through a narrow hydrogen alpha filter that trace emission from atomic hydrogen. Reddish hydrogen emission regions, called HII regions, are the regions of intense star formation seen to lie mainly along M51's bright spiral arms. Intriguingly, this composite also shows red hydrogen emission structures in the faint features extending even beyond NGC 5195, toward the top of the frame.

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[Mizzou]

A beautiful shot for my birthday (June 11)!!

[orin stepanek]

Like fireworks going off! Happy B-day Mizzou.

[Beyond]

WOW!!!! - A fight in outer space between two Galaxies. Seeing as how it should have been over by the time we get the view, i wonder who won?
I've never seen a Galaxy take a swipe at another galaxy before. Any one know what the rules are?

[rstevenson]

... I've never seen a Galaxy take a swipe at another galaxy before. Any one know what the rules are?

Gravity.

Rob

[hakescl]

Backwards!

[neufer]

Hydrogen in M51

This dramatically processed color composite combines M51 image data from the Calar Alto Observatory's 1.2 meter telescope. The data include long exposures through a narrow hydrogen alpha filter that trace emission from atomic hydrogen.

<<The Calar Alto Observatory is an astronomical observatory owned and operated jointly by the Max-Planck-Institut für Astronomie in Heidelberg, Germany, and the Instituto de Astrofísica de Andalucía (Institute of Astrophysics of Andalusia) in Granada, Spain. It is located in Almería province in Spain on Calar Alto, a 2,168-meter (7,113 ft) high mountain. The site was proposed in 1970, and was officially opened in July 1975 with the commissioning of its 47-inch (1.2-meter) reflecting telescope. The Schmidt telescope was moved to Calar Alto in 1976 from the Hamburg Observatory at Bergedorf, where it had been completed in 1954.>>

<<What was later known as the Whirlpool Galaxy was discovered in 1774 by Charles Messier, and is designated as M51. Its companion galaxy, NGC 5195, was discovered in 1781 by Pierre Méchain. It was however not until 1845 that the Whirlpool became the first to be recognized as a spiral. This was achieved by Lord Rosse employing a 72-inch (1.83 m) reflecting telescope which he constructed at Birr Castle, Ireland.>>

[Beyond]

Geeze....I ask if anyone knows what the rules are and all i get is - gravity and backwards. It hardly paid to get up this morning.
Seeing as how Galaxies have no hands and the closest one is spinning to the right - the farthest Galaxy is receiving a "back-arm" from the closest one.
As for rules, i suppose you could say they would come under the Heading of -- Stuff happens and you do the best you can with it.
Its to bad it takes so long to see whats happening. I can tell that closest Galaxy is in the process of giving the farthest Galaxy the ole' 1-2 punch, as its second arm is begining to flex to give the farthest Galaxy a second back-arm punch.
Yep, it sure is amazing what a couple of pieces of curved glass started, isn't it

[bystander]

A new look into the Whirlpool Galaxy
Science Centric | 11 June 2010

[ianfs]

Yes, what about this. The Wikipedia image shows a clockwise rotation, while the Astronomy Picture of the Day shows a counter-clockwise one. Is this just careless image processing, or is there a reason for it? Which is the correct one?

[Chris Peterson]

Yes, what about this. The Wikipedia image shows a clockwise rotation, while the Astronomy Picture of the Day shows a counter-clockwise one. Is this just careless image processing, or is there a reason for it? Which is the correct one?

Neither is "correct". It is most common to display astronomical images as north up, east to the left. That makes them correspond to conventional star maps. But that is just convention. The way this APOD is displayed is unconventional, but not really incorrect, and not that uncommon.

If you were to look at M51 with the naked eye, you'd see a clockwise spiral pattern. If you looked at it telescopically, it would depend on the nature of the optics.

[FrogSplash]

WOW!!!! - A fight in outer space between two Galaxies. Seeing as how it should have been over by the time we get the view, i wonder who won?
I've never seen a Galaxy take a swipe at another galaxy before. Any one know what the rules are?

I'd think violent oh so violent. Ripping worlds and suns apart. Imagine some of those worlds populated. It would be something very scary and I'm glad we won't experience it in our life times.

FS

[Chris Peterson]

I'd think violent oh so violent. Ripping worlds and suns apart. Imagine some of those worlds populated. It would be something very scary and I'm glad we won't experience it in our life times.

No suns are being ripped apart; no worlds are being ripped apart. If any of these stars have inhabited planetary systems, it is unlikely that anything has changed for them. Their entire system may be shifted into a new orbit, but that wouldn't matter. There are two bad things that could happen, and both are probably pretty uncommon. If a star passed close enough to another, its planetary system could be perturbed, sending planets into new orbits or out of the star system completely. And if a star was in a region of dense gas and encountered another such region, it could find itself in a zone of new star formation, which might have radiation consequences. But mainly, things within planetary systems would continue as usual.

[Beyond]

We have the small version of it here. Its called warfare. The scarier version comes next -- Atomic warfare.
Perhaps one day someone from a far off galaxy will be looking through a telescope in our direction and all of a sudden notice big mushrooms all over the planet and begin theorising what could possibily cause such an event and perhaps if there was any intelligent life-forms involved.
I would have to say no to there being any intelligence being involved.

[Ann]

It's a beautiful picture. Happy Birthday, Mizzou!

Ann

[D0lphina]

This is a beautiful picture!!
But if Hydrogen in M51 is 60,000 light-years across...our "galaxy" looks something like this (right ) ....I am just wondering how many light years is our "galaxy" across??

[Chris Peterson]

But if Hydrogen in M51 is 60,000 light-years across...our "galaxy" looks something like this (right :?:) ....I am just wondering how many light years is our "galaxy" across?? :?

Our galaxy is a bit larger, about 100,000 light years in diameter.

[flash]

Chris Peterson wrote:
If you were to look at M51 with the naked eye, you'd see a clockwise spiral pattern.

Is that clockwise spiraling in, or spiraling out?

[neufer]

Chris Peterson wrote:
If you were to look at M51 with the naked eye, you'd see a clockwise spiral pattern.

Is that clockwise spiraling in, or spiraling out?

• Clockwise spiraling out.

[Beyond]

ALL RIGHT!!!! - Flower - Power!!!!

[Wackybaby]

Isn't that fascinating, that similar mathematical laws that make up the structure of a small flower, are also evident in the structure of humungous galaxies?

[D0lphina]

But if Hydrogen in M51 is 60,000 light-years across...our "galaxy" looks something like this (right ) ....I am just wondering how many light years is our "galaxy" across??

Our galaxy is a bit larger, about 100,000 light years in diameter.

WOW!! I did not know that..that is quit a bit BIGGER
Thanks

[owlice]

sunflower1smaller.jpg (33.68 KiB) Viewed 3873 times

[bystander]

From CAHA: A New Look into the Whirlpool (image release)


M51 and NGC 5195 Left: True Color Right: H-alpha enhanced

[rstevenson]

For those who might be interested in running a simulation of a galaxy collision on your computer, and being able to change parameters to see how the result is affected, have a look here. On that page you can view an on-line demo, and then download the free Mathematica Player application and the Colliding Galaxies simulation file to play with.

Colliding Galaxies is an extremely simple simulation, with the paths of the stars being affected only by the centers of gravity of the two galaxies, and not by other stars. But it's fun to try anyway.

I found settings which give a nice example of colliding galaxies clearly showing how stars get ripped out of the smaller galaxy and begin to orbit the larger one, but not in the same plane as the other stars in that larger one. From top to bottom the settings to see this are... 60,38,6,10,0.1,-50,50,50,0,0.16,0.12

Enjoy.

Rob