Comments on: Gorgeous globular hides hundreds of rejuvenated stars

By: tracer

tracer — Thu, 06 Oct 2011 21:39:30 +0000

Back in my college days, I learned that globular clusters only undergo one wave of star formation when they first form, and never form new stars. Apparently, there ARE planetary nebulas and supernova nebulas that get blasted into space by stars within the globular cluster when they die — but the globular cluster’s in orbit around the center of the Milky Way, and every time the globular cluster passes through the plane of the galaxy the plane acts like a “strainer” and sucks all the gas and dust out of it.

(Why and how the galactic disc does such a thing, I didn’t really understand.)

Upshot: All the stars within a globular cluster formed at the same time, and the material they formed out of was very heavy-element-poor (i.e. all the stars are Population II), so there will be no space aliens living there.

By: Glissade

Glissade — Tue, 04 Oct 2011 19:50:03 +0000

Imagine the view from a planet orbiting one of the stars during such a merger.

By: Bob_In_Wales

Bob_In_Wales — Tue, 04 Oct 2011 12:39:17 +0000

Actually, since two stars colliding and merging is REALLY REALLY unlikely, blue stragglers are proof that the Universe isn’t as old as Phil thinks it is! Maybe only about 6,000 years actually.

Joking. JOKING!

Personally I always find that it is pictures like this that begin to bring home to me what living in a universe of ~10^22 stars means. Thanks for the post Phil.

By: M54 where are you? « History is made at night

M54 where are you? « History is made at night — Tue, 04 Oct 2011 11:17:31 +0000

[...] to not taking credit for stuff when I shouldn’t. For example: I read on Phil Plait’s Bad Astronomy blog about M53, a globular cluster that’s (sort of) recycling its stars, and now I’m [...]

By: Ganzy

Ganzy — Tue, 04 Oct 2011 11:04:48 +0000

@19 Thanks Wzrd1, I understand what interpolation is now. It would have been disappointing to get the new wall paper delivered only to find it full of “jaggies”.

By: Wzrd1

Wzrd1 — Tue, 04 Oct 2011 04:44:50 +0000

Messier, why not? M54 was partially absorbed several times passing through the Milky Way, left a nice trail of stars.

Artor, I dunno. Seeing two LARGE stars merging, then hypernova would most certainly be crazy cool!
Watching a pair instability supernova would be cool too.
But then, Scotty informed me, the new deflector shields won’t be installed until NEXT Tuesday.

Seriously though, think of two brown dwarfs joining and gaining sufficient mass to initiate fusion.
THAT would be a sight to behold!

By: Artor

Artor — Tue, 04 Oct 2011 03:38:09 +0000

I’d love to see an animation of two stars colliding to make one of these “blue stragglers.” That would have to be one of the more spectacular sights the universe has to offer.

By: Messier Tidy Upper

Messier Tidy Upper — Tue, 04 Oct 2011 02:46:06 +0000

I will never, ever get tired of insanely gorgeous images of globular clusters.

Me either!

Superluminous image here. Love it!

That is Hubble’s view of M 53, a cluster of several hundred thousand stars crammed into ball about 60,000 light years away — well outside the Milky Way itself, but bound to it, orbiting our galaxy.

Hmm … isn’t Messier 53 *inside* our Milky Way’s extended Galactic Halo region then? Our Galaxy doesn’t stop at the spiral arms and central bulge y’know!

Or does M53 actually orbit – at least partially – in intergalactic space outside of our Galaxy’s halo? Anyone know?

If so, is that perhaps an indication that M53 formed around (or even was itself?!) another galaxy and has subsequently been captured by our Milky Way?

By: Wzrd1

Wzrd1 — Tue, 04 Oct 2011 02:04:33 +0000

Well, the large size image is 16.6 megs in size. That should blow up nicely without excessive pixelation. Especially if interpolated, to prevent “zaggies”.

By: Ganzy

Ganzy — Tue, 04 Oct 2011 01:58:37 +0000

Beautiful! Another cosmic sparkler. For a long time I have wanted to fill an entire room wall in my home with a globular cluster like this. There are quite a few companies online now that will blow an image like this up, and print it onto wallpaper for you. The prices are reasonable now. Anyone know what kind of image size I would need, pixel-wise, to englobunate this onto a wall 4 metres by 2.4? Or is it just a case of the largest pixel image I can get hold of?

When I get it done I’ll post a link to a pic.

By: Brian Too

Brian Too — Mon, 03 Oct 2011 23:26:48 +0000

@6. Relativity,

I feel confident in saying that the merged stars (blue stragglers) will experience life as a short-lived blue giant. Assuming of course that they achieve the mass of a blue giant.

Stellar lifespans are determined by the mass and temperature of the object. What they were before merging is of little consequence, unless both predecessor stars were very, very old and used up their hydrogen. Even then the consequence would simply be that the merged star would have an even shorter lifespan.

By: Wzrd1

Wzrd1 — Mon, 03 Oct 2011 23:23:42 +0000

The thing’s hollow—it goes on forever—and—oh my God—it’s full of stars!

By: Trebuchet

Trebuchet — Mon, 03 Oct 2011 22:52:39 +0000

I was surprised it took until no. 10 for someone to mention Nightfall! Gorgeous.

By: Musical Lottie

Musical Lottie — Mon, 03 Oct 2011 22:38:58 +0000

Wow. My jaw actually dropped.

By: Jess Tauber

Jess Tauber — Mon, 03 Oct 2011 22:06:05 +0000

Are masses of blue stragglers ever large enough to produce a supernova?

By: James

James — Mon, 03 Oct 2011 20:14:47 +0000

To paraphrase a very wise and interplanetary traveler: “When 12 billion years old you reach, look as good you will not.”

This is so my new desktop.

By: MadSciKat =^..^=

MadSciKat =^..^= — Mon, 03 Oct 2011 19:45:56 +0000

Wow. Just wow.

By: John

John — Mon, 03 Oct 2011 19:09:24 +0000

This image makes me think of Asimov’s Nightfall.

By: Dizzy

Dizzy — Mon, 03 Oct 2011 19:01:13 +0000

“Click to embiggen…..”

Surely old bean, you meant to say “Click to englobulinate…”

Oh yes, spectacular image.

By: Robin

Robin — Mon, 03 Oct 2011 18:55:12 +0000

Man, this place is huge, but it has great lighting!

By: johnthompson

johnthompson — Mon, 03 Oct 2011 18:51:03 +0000

Well, as they say, NOT EXACTLY: even in the cores of globular clusters, direct collisions (where the photospheres of the stars actually touch) are extremely, extremely rare. The two ways in which blue stragglers CAN form involve a) NEAR collisions in binary (or larger) systems where stellar exchanges and all matter of weird interactions are possible (single stars coming close to each other and forming a binary is impossible due to conservation of energy and angular momentum, unless a third object is involved) and b) “normal” mergers of close binaries as angular momentum is shed thru mass loss from the system (and some also thru gravitational radiation). The FK Comae stars found in the field are thought to be formed in this manner. Still a very pretty image though it would be nice to know how big it is on the sky (if one “clicks thru” you can find that it’s 3.4 arcminutes on a side)..

By: Relativity

Relativity — Mon, 03 Oct 2011 18:49:41 +0000

Interesting as always Phil.

If two (or more) stars formed one of these blue stragglers, will their lifespan now become what a normal blue star would experience and die off (in a supernova, of course) in a few or hundred millions after the merging event? Or would they continue to be a long-lived, but bigger and brighter version of their old selves?

By: Larian LeQuella

Larian LeQuella — Mon, 03 Oct 2011 18:26:55 +0000

They say you learn something new every day. I learned about Blue Stragglers, so I guess my day is done! Thanks.

By: Ian

Ian — Mon, 03 Oct 2011 18:17:28 +0000

Amazing. First thing I saw through a telescope was a globular cluster. After that they became my personal favorites. So MANY stars!

By: Andrew

Andrew — Mon, 03 Oct 2011 18:13:01 +0000

I don’t know/doubt if I’m the first to ask this, but there should be some kind of ap/pc program that just downloads these when they are posted and sets it as wallpaper. Any programmers follow this blog might be willing to throw something together? Or anyone know of one that already exists in some form? I doubt (with no basis whatsoever for saying so) it would be overly complicated.