The gorgeous birth pangs of young stars

By Phil Plait | December 2, 2011 11:05 am

The Sun is literally a middle-aged star; approaching the midpoint between its birth over 4 billion years ago and its eventual death about 6 billion years from now. But the Sun is one of hundreds of billions of stars in the Milky Way galaxy, and we see them at all different ages, from their spastic births to their (in some cases) hyperspastic deaths. In many cases the way a star dies is foretold by how its born, so the study of star birth is a rich and fascinating field.

It’s also surpassingly beautiful, since stars are formed from the swirling chaos of thick clouds of gas and dust, lit up by the various newborns embedded within. You’ll find no finer example of this than the large nebula called Sharpless 2-239, a sprawling stellar nursery about 500 light years away in the direction of Taurus, and you may find no finer picture of it than this one taken by astronomer Adam Block using the 0.8 meter telescope at the Mt. Lemmon SkyCenter in Arizona:

[Click to ennebulenate, and yes, you want to.]

Isn’t that breathtaking? This image shows a portion of a much larger complex which currently has over a dozen stars forming inside it. Several of the stars you see here are quite young, only a few million years old. Since these are low mass stars like the Sun, and will merrily fuse hydrogen into helium for billions of years, this is like seeing a human baby when it’s less than a month old.

And, like babies will, these stars eject material from both ends: called bipolar outflow, twin beams of material (typically called "jets") are screaming out of these newborns at several hundred kilometers per second in opposite directions. These jets slam into the dense surrounding material, compressing it, heating it up, and causing it to glow. The structure you see fanning out to the lower left is from one of these jets, the one headed more or less toward us. The one moving in the other direction is mostly hidden from our view by the thick dust in the region.

But there’s much much more going on here…

The red blob at the tip of apex of the fanned-out structure (just to the left and above the center) is the baby star causing all this commotion. It’s called IRS5, or sometimes HH154, and it’s the one emitting jets. The pink color you see in the picture is from warm hydrogen gas glowing due to this mechanism, and the other colors are coming from elements in the gas like oxygen, nitrogen, and sulfur. As you can tell, the material farther out is quite dark, and in fact is so thick it absorbs the light from the stars inside; if they weren’t so active we wouldn’t see them at all!

At least, not in visible light. When you look in other wavelengths, you see deeper into the dust. The image above, taken by the infrared 2MASS survey, shows the glow of the star and nebulosity just outside the eye’s range of color (I rotated the image and changed the scale to better match the image above). Light from deeper inside the cloud can be seen, and you can now see the young star lighting up the small wisp of gas above and to the right of IRS5 — a star that’s invisible in the first image.

Things get even more interesting if you use a big telescope with high-resolution to zoom in on the star in the infrared. Using the monster Subaru telescope in Japan, astronomers obtained this next image of IRS5, and you can clearly see the jet of material… except, wait a sec, there are two jets!

Yup. That’s because IRS5 is actually a binary star, two young stars orbiting each other. In fact many of the stars in Sh2-239 are binaries.

In the case of IRS5, the two stars are about 10 billion kilometers apart — bigger than the diameter of Neptune’s orbit. Each star is surrounded by a flat disk of material probably 3 billion kilometers across composed of leftover material from the formation of the stars; this material may even form planets in the coming eons.

Amazing, isn’t it? What appears to the eye at first as a formless blob actually takes on a interesting shape when you start to look more closely. And when you look differently, you see structure that yields more insight on the actual events going on: the birth cries of young stars, and not just any stars, but twins!

When Adam sent me that picture, I wanted to know more about this object, so I dug a bit deeper. I found all the information posted here, as well as much more (like, the jets are ramming the material around them so violently the gas is emitting X-rays 100 times more brightly than the Sun’s X-ray emission, but it’s difficult to detect due to the chokingly thick material surrounding the system).

I love looking at pretty astronomical pictures as much as the next person, but what gets to me is that these are far, far more than just snapshots of the cosmos. These are telling us stories; complicated, wonderful, deep stories of the complexity and history of the Universe, which in turn will certainly yield insight into the birth and evolution of our own Sun and planets. By looking out, we look in, and find that the farther we voyage, the closer to home we get.

Image credits: Adam Block/Mount Lemmon SkyCenter/University of Arizona; Atlas Image obtained as part of the Two Micron All Sky Survey (2MASS), a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by the NASA and the NSF; Subaru Observatory via ESA; K. Borozdin, Los Alamos National Laboratory, USA


Related posts:

- Hubble celebrates 20 years in space with a jaw-dropper (MUST-SEE image. Trust me here.)
- C-beams off the shoulder of Orion
- Spitzer sees star spew spurious spouts
- Baby stars blasting out jets of matter

CATEGORIZED UNDER: Astronomy, Pretty pictures, Top Post

Comments (26)

  1. Spad31

    Nice. Thanks, Phil.

    -T

  2. We’ve seen pictures of supernovas (“supernovae”?), and then had people go back and find “pre-nova” images of the star.

    But, has anyone ever seen a stellar “birth”, where a new star appears where previously there wasn’t one? (Okay, I suspect that the actual ignition is hidden behind lots of dust. But at some point, the star will blow away enough dust for us to see it.)

  3. Chris

    And, like babies will, these stars eject material from both ends: called bipolar outflow

    I see a marketing opportunity here for infant wear. “I’m a baby star. I eject material from both ends.”

  4. Gary Ansorge

    “Yoh, Baby, I wanna talk to yo Momma,,,”

    Ejecta at both ends is the best short description I’ve ever heard of what babies do,,,

    Gary 7

  5. TMB

    Subaru is on Mauna Kea in Hawaii, not in Japan (though it’s owned by Japan).

  6. Dr. Strangelobe

    It’s paradoleia time again! Does anyone else see a figure in a dark robe, eyes glowing, as it presents a protostar in either hand (?) ?

  7. Dave Jerrard

    I never, EVER, thought I’d write this, but….

    ennebulenation error. Page not found.

    He Who Really Wanted To Ennebulenate Too.

  8. Endyo

    “By looking out, we look in, and find that the farther we voyage, the closer to home we get.”

    This is my absolute favorite aspect of astronomy.

    Also, as has been said, your image links are linking to error pages.

  9. BertieMk2

    The first image reminds me of a dark wizard as seen from behind. His black cloak flowing up to his crowned head. His left hand, balled into a fist, coursing with necromantic energy.

  10. Thomas Siefert

    The Sun is literally a middle-aged star

    Any day now it will quit it’s day job and go buy a Porsche.

    Joke aside, few people make the material come alive like you do BA.

  11. Chris

    @9 Thomas
    Should we be worried about the sun having a midlife crisis?

  12. Ryan

    Question: What happens to a stellar nursery nebula once the stars are formed? Do solar winds blow all the dust and debris away that aren’t part of planet / star formation until the density is so low we don’t see it as a cloud?

    We obviously don’t live in the center of a nebula, so I always wondered that. Must be a yellow dwarf thing, being s smaller and later generation star?

    Then that leads to the question, how hard is it for a later generation star to form in a nebula being ripped apart from earlier stars.

  13. Thomas Siefert

    Should we be worried about the sun having a midlife crisis?

    My only worry in that respect is that a certain director is no longer distracted by the Transformer franchise and will use it for the plot of his next science fiction blockbuster.

  14. In fact many of the stars in Sh2-239 are binaries.

    I’ll go one step further here and note that most of the stars in the universe are binaries. ;-)

    Although I may be mistaken on this I think the figure is that about 70 % of all stars have stellar companions. High mass stars in particular tend to be in multiple star systems with this being somewhat less common for red dwarfs although many low mass stars do also have companion stars eg. UV Ceti, Kruger 60 and SCR 1845-6357 with its brown dwarf companion. (Click on my name for link for the latter.)

    I love looking at pretty astronomical pictures as much as the next person, but what gets to me is that these are far, far more than just snapshots of the cosmos. These are telling us stories; complicated, wonderful, deep stories of the complexity and history of the Universe, which in turn will certainly yield insight into the birth and evolution of our own Sun and planets. By looking out, we look in, and find that the farther we voyage, the closer to home we get.

    Very well said and seconded by me, BA. Thanks – great article here as usual. :-)

    I’ll add one other thing to this : Nothing puts one’ s life and all the mundanities of, well everything, into perspective and nothings expands the mind and imagination quite as much as astronomy and looking up into the sky, wondering and learning in my view. :-)

  15. Meghan

    Is it possible to see star births with the human eye? Because I saw an incredibly bright star in the sky flashing brightly and it looked as if it were moving a little, and then I found this article. I know very little about stars, so I am just wondering!

  16. Zack B

    sorry once in like 35-50 years*

  17. Gary Ansorge

    15. Meghan

    The human eye, in a dark desert, is only able to perceive about 3000 stars, so the short answer would be,,no. Stellar nebula are way to far away and dim to be seen w/o assistance.

    If what you saw was “blinking” and appeared to move, it was most likely either a high altitude aircraft or a satellite,,,

    Gary 7

  18. Andrew

    Low mass stars like the Sun? I though at least three quarters of starts were less massive than the Sun. The Sun man not be a giant, but it is on the large side for a dwarf.

  19. @#11 Chris: Should we be worried about the sun having a midlife crisis?
    That depends. If it leaves us for a planetary system that’s only 2 billion years old, Sol will leave us SOL.

  20. @17 Gary Ansorge: If what you saw was “blinking” and appeared to move, it was most likely either a high altitude aircraft or a satellite,,,

    I’d also add that very bright objects, like Venus, (or Jupiter, now fairly close to opposition and pretty bright) often appear to “blink” more because of atmospheric scintillation, and that the human eye will often see a bright point source as “moving” (one reason why so many UFO sightings turn out to be Venus). I’d bet on Venus if it was just after sundown, Jupiter if it was later at night.

  21. @#2 Ken B: But, has anyone ever seen a stellar “birth”, where a new star appears where previously there wasn’t one? (Okay, I suspect that the actual ignition is hidden behind lots of dust. But at some point, the star will blow away enough dust for us to see it.)

    Well, not really. Unlike a supernova, which is a transition from star to neutron star/black hole/nothing in a matter of hours or minutes, star birth happens relatively slowly. The proto-star slowly contracts – the gravitational potential energy of the star-stuff is converted to heat, and this heat keeps the contraction from proceeding too quickly. These proto-stars can actually shine more brightly from the heat of formation then the young actively fusing star that it becomes. Inside the star, processes can take quite awhile to normalize. For instance, you have convective and non-convective layers forming as the core heats up. And even once fusion is ignited in the core, it can take many thousands of years for the fusion energy to actually make it to the surface.
    In a nutshell, it takes a very long time (by human standards) for protostars to become stars, long enough that there isn’t a tremendous amount of change in any “birthing” star in a human lifetime*. I think a better metaphor then birth might be growth from a baby to an adult

    *This is what I understand to be true, but I may be totally wrong. Take with a grain of salt :)

  22. Nigel Depledge

    The BA said:

    And, like babies will, these stars eject material from both ends: called bipolar outflow, twin beams of material (typically called “jets”) are screaming out of these newborns at several hundred kilometers per second in opposite directions.

    Wait, what?

    How many babies have you encountered with “bipolar outflow” measured at several hundred km/s???

  23. Zack B

    And my post was erased incredible hats off to censorship..

  24. @22 Nigel Depledge: That number may be high, but when it’s happening in front of you, it can seem like it ;)

    @23 Zack: Did it have a link in it? Any posts with links are automatically subject to moderation.

  25. Christian Ready

    I was working on another video until I came across this post. Doggone it, now I had to go and make a video about this instead! :) http://youtu.be/U_lrWcMYhP0

    Thanks for the great writeup, Phil!

  26. Nigel Depledge

    Zack B (23) said:

    And my post was erased incredible hats off to censorship..

    What I find incredible is how many occasional commenters whose comments go into moderation or disappear for some other reason then comment to whine about censorship. If Phil really censored comments, what makes any of you think he’d allow a comment commenting about censorship through moderation?

    In fact, there is only one reason why Phil will delete a post, and that is if the comment is outright offensive i.e. not family-friendly. Kids read this blog too.

    You only have to look at some of the insane stuff that people post (for example, in threads about AGW) to realise that, if Phil wanted to censor comments, he would certainly censor those comments.

    If your comment failed to appear, maybe it got lost in the intertubes somewhere, or maybe you failed to enter an email address (I’ve done this, when using a computer different from the one I normally use to visit, losing sometimes 15 or 20 minutes’ worth of typing through having forgotten to fill in that field).

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