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Hubble Shoots Movies of Stellar Jets
With his first accepted submission, aglider writes "A number of different science publications are reporting on a recent announcement made by NASA and Hubblesite.org. Quoting: 'A team of scientists [headed by Rice astronomer Patrick Hartigan] has collected enough high-resolution Hubble Space Telescope images over a 14-year period to stitch together time-lapse movies of powerful jets ejected from three young stars. The jets, a byproduct of gas accretion around newly forming stars, shoot off at supersonic speeds in opposite directions through space.' The report is also accompanied by a number of photos and, of course, astounding small movies. The complete scientific study, which dates back to 2011.07.20, has been published in the Astrophysical Journal (subscription needed) but is also available on the ESA's Space Telescope site (PDF)."
way to waste a first post there
of course, it means faster than the speed of sound in a vacuum...
This is awesome! Finally a real, optical series of images for something like this -- no infrared, or otherwise exotic EM 'images'. This moves us one step closer to what I really want to see before I die -- a supernova actually bursting and wiping out its star system in real imagery.
Hopefully we put another good, optical tele up there so we can get a bit better resolution so we can see the scales of a star system and not 14years worth of 440k mph stills.
The tail of a comet is caused by the star around which it orbits heating it up and blowing off the dust into a 'tail' shape. The tail does not trail behind the comet as it moves, but points away from the star it is orbiting.
Does this give anyone else the impression that we are like insects, living, moving, dying too fast to appreciate the slowly unfolding majesty of the Universe?
speed of sound (in the interstellar medium) is about 100 km/s
(source)
Yes, really.
Moron.
Wow, they move faster than sound in space. Wonder what speed that is? Are orbiting space loudspeakers blasting rock-n-roll to unfortunate planets next? (Apologies to Douglas Adams)
Cool videos, though.
Nate
From one of the videos it looks like a tail caused by the star moving... Could there be star-sized comets in the universe?
It depends on what you want to call a comet. The "dirty snow balls" at the nucleus of all the comet pictures you'd normally see are no bigger than an asteroid. When activated by solar energy, they develop a coma of gaseous material that is several times larger than the nucleus, but still pretty small. If you count the tail that streams away from the star, then yes: it is possible to say a particularly large and active comet can conceivably approach the diameter of a star. However, even as such, no comets are observable with today's technology at stellar distances of the order those Hubble observations are made.
========== "Hello World" in my programming language of choice: ATG - LET THERE BE LIFE - TAG ==========
i would have modded you up
Specifically the HH1 jet has some of the streaming blob like motion created using light show fluid projections techniques. This is done on an overhead projector with a big watch glass (a big shallow section of a sphere) and volatile fluids. Colors are dripped into the liquid and as the glass is moved they mix around and bubbles form from a combination of the heat of the projector and changing pressure in the liquid.
It's all fluid dynamic, in outer space on a table top.
Why is Snark Required?
The post mentioned "The jets [...] shoot off at supersonic speeds..." While determining supersonic speed requires not being in a vacuum, once you know what speed supersonic-speed is, can it not be used as a measuring stick for comparison? If I'm moving at a snails pace, I'm likely not crawling across the ground, in fact, I could be doing any number of non-transportive activities that could be claimed to be at a snails pace.
"While determining supersonic speed requires not being in a vacuum, once you know what speed supersonic-speed is, can it not be used as a measuring stick for comparison?"
Supersonic means faster than the speed of sound referenced to a specific medium at specific conditions, and that varies wildly depending on the medium, say air or steel, and on the temperature, pressure, and state of the medium. Perhaps astro-physicists use "supersonic" in some specialized sense, but it looks to me as if the author used it as a synonym for "very fast" much as "healthy" is used in place of "large" or "big".
Nate