Jets of supersonic gas take turns erupting off a young sunlike star. Newly released images from the Spitzer Space Telescope show that one jet lags four-and-a-half years behind its identical twin.
"More studies are needed to determine if other jets have time delays," astrophysicist Alberto Noriega-Crespo of Caltech, a co-author of a study in the April 1 Astrophysical Journal Letters, said in a press release. "Now, we know that in at least one case, there appears to be a delay, which tells us that some sort of communication may be going on between the jets that takes time to occur."
Young stars usually send off symmetric jets of dust and gas as a normal part of their growth. A star starts life as a rapidly spinning and collapsing cloud of hot gas. The baby star gathers material around itself in a swirling disk, which might eventually coalesce into planets.
The combination of the star's speedy spinning and strong magnetic field shoots twin jets of material above and below the disk, making the star look like a spinning top. The jets, which sometimes clump up into little knots and asymmetries, help slow down the infant star's rotation. Once the star ignites and begins shining, the jets die off, and the disk thins out.
But this object, called Herbig-Haro 34, seemed to have just one jet in visible-light images. The Spitzer images, which capture the warm glow of infrared light, show that the second jet was hidden behind a dark cloud. The image reveals that the second jet is perfectly identical to its twin, with symmetrical knots and whorls of material.
The only difference is, the second jet is late.
By measuring the exact distances from each knot of material to the star, the researchers determined that, for every knot of material in one jet, a similar knot shoots out of the other jet 4.5 years later.
The jets are probably communicating though some sort of cosmic secret-twin language, possibly carried by sound waves, the researchers say.
Our own sun may have displayed similar see-saw jets when it was growing up. The researchers also found that the jets are created in the inner 280 million miles of the disk, about three times the distance from the Earth to the sun.
"Where we stand today on Earth was perhaps once a very violent place where high-velocity gas and dust were ejected from the disk circling around our very young sun," Alex Raga of the Universidad Nacional Autónoma de México, a co-author of the paper, said in the press release. "If so, the formation of planets like Earth depends on how and when this phenomenon ended."
Image: NASA/JPL-Caltech
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