Apparent and Real Sizes of M42 and Carina Nebulae

[avandonk]

It occurred to me I had images of both m42 and Carina taken with the same equipment under very similar conditions. So I used PS to put them together at the same scale.

The Orion Nebula NGC 1976 or M42 is located 1300 light years away and is about 24 light years across.

The Carina Nebula NGC 3372 is located 8800 light years away and is about 460 light years across.

If Carina was at the same distance as M42 it would cover about 20 degrees of sky.

The second image has them at their real relative sizes.

Makes you wonder which should have the label 'great'.:D

Bert

[DavidU]

Nice perspective. 3372 is a monster.It's going to be even more monstrous.

[avandonk]

We could go on and compare Carina to the Tarantula Nebula at 180,000 light years away.

Below is an image of the Tarantula with Carina inserted at real relative sizes (if my calculations are correct?). Can you spot Carina?

Bert

[Starkler]

Now thats cool Bert. If m42 was in the last pic it wouldnt be looking too great at all.

[mithrandir]

Yep. If you'd masked the sharp edges it would have been harder. :P

[sjastro]

Interesting comparison.

All pip squeaks compared to NGC 604. Now that would be a sight if it was in our own galaxy let alone at the same distance as M42.

Steven

[AlexN]

Fantastic work Bert.. As I understand it, if the Tarantula was as close to us as M42, The tarantula would span the entire night sky, and be bright enough to cast shadows!

The visual representation of M42/Eta Car/Tarantulas "Actual" size difference is amazing.. Its great to see what kind of a difference perspective can make.....

I think if you were going to call Orion "Great" from now on, you'd want to be referring to the entire Orion molecular cloud... M42/IC434/NGC2040/M78 and Barnard's loop... that, is a great big molecular cloud... !

[avandonk]

Thanks for that info Steven. I think my 100ED would be hard pressed to get an image of NGC 604. At 1500 light years across that is three times bigger than Carina. So that puts it at about the same size as the Tarantula Nebula.

I may dig up a Hubble image and see what I can do.

Bert

[kinetic]

Great comparisons Bert and Steven...

Steve

[jjjnettie]

Thanks Bert.
You're a mine of useful information.

[strongmanmike]

That's a pretty cool comparison Bert, you really are Mr Registar :thumbsup:

Here is a comparison of apparent sizes only of 4 well known Globulars I did a number of years ago. All 2min exposures through a 12" SCT:

http://www.pbase.com/strongmanmike2002/image/55303640/original

Mike

[avandonk]

Alex by putting together this comparison it made it far clearer to me exactly what we are looking at even if it was only a size consideration.

We and everything around us are all made from the stuff of these gaseous dusty nebulae. They all produce new stars with planets and then inevitably life. They themselves are the product of countless supernovae and many generations of stars.

Never mind genealogy we can see and now understand what makes us.

It was within my lifetime that nuclear synthesis in stars was first understood by Hoyle. As was the production of elements with a greater atomic number than Iron 56. These can only be produced in a supernova.

We now can manipulate at will the molecules that make all life on this planet. This has happened in just the last twenty years.

We are a bit further from when we crawled out of the primeval ooze.

Bert

[AlexN]

My bad... Spelling corrected..



It is amazing to think that at some point, many millions of years ago, we were all the components of a star... the star reaches critical mass and explodes, flinging matter every which way, and some how, all the right matter seems to group at just the right point to create a planet, orbiting at just the right distance from its star, with just the right elements to sustain life, and life springs forth.

To think that the same star that created all the right materials for humans to exist, also created the right materials for dinosaurs, fish, birds, the whole lot...

Its pretty amazing.

[avandonk]

Alex our solar system formed 4.67 billion years ago from dust and gas. Our system has a third? generation star. By third I mean that the majority of material that is our solar system on average has been through three cycles of stellar birth and then to planetary nebulae and supernovae.

This age can be deduced from the isotopic ratios of very long lived radioactive isotopes in meteorites. These isotopes have a long half life and the ratios change in a known way from the time of their creation in a supernova.

If I stick to the correct Latin plurals blame the Christian Brothers who would strap me for getting my Latin plurals and declensions wrong.

Bert

[avandonk]

Whats a good lookiing girl like you. I just realized that avatars are like smilies. No they are not!

Bert

[multiweb]

Interesting comparison on the nebulae. Wasn't aware that our solar system was on take III. By isotopes in meteorites, are you saying that some of the material in their composition has survived 3 cycles?

[avandonk]

No Marc these meteorites are leftovers from the formation of our solar system and give us information of the starting stuff and its origins. The simple fact that that it takes cycles of stellar nucleosynthesis to produce heavier elements than the original Hydrogen and Helium with a tiny bit of Lithium from the big bang is now well understood.

Bert

[multiweb]

The "starting stuff" containing elements from previous cycles?

[avandonk]

Yes they do and the more heavy elements the more cycles. I vaguely remember about a paper on a globular cluster that was almost devoid of heavy elements and so it was considered it could be very old. Nearly as old as the Universe.

Bert

[jjjnettie]

Hate to tell you Bert, but that was David Bowie looking back at you in my Avatar. He was a pretty boy back then, was he not?:)

[avandonk]

I was only joking about avatars. I meant to cut out a bit of text and your avatar popped up in the reply window. So I put in mine. Apparently it is a HTML thingy. I thought it was obvious by the tenor of my statement that nothing further was implied.

Bert

[jjjnettie]

LOL Bert, I'm exhausted from work atm and know not what I write.

[Hagar]

Great work Bert, Hard to imagine these comparative sizes when looking at a computer monitor. The distances refered to are beyond my conception by them selves.

[avandonk]

Doug who was it who said 'infinity is a really long way especially the last bit'?


Bert

[TheDecepticon]

Great comparisons!:) I often wonder about this.:question: