VLA shows earliest stages of planet formation

March 17, 2016
Combined ALMA/VLA image of HL Tau. Credit: Carrasco-Gonzalez, et al.; Bill Saxton, NRAO/AUI/NSF.

New images of a young star made with the Karl G. Jansky Very Large Array (VLA) reveal what scientists think may be the very earliest stages in the formation of planets. The scientists used the VLA to see unprecedented detail of the inner portion of a dusty disk surrounding the star, some 450 light-years from Earth.

The star and its were studied in 2014 with the Atacama Large Millimeter/submillimeter Array (ALMA), which produced what astronomers then called the best image ever of planet formation in progress. The ALMA image showed gaps in the disk, presumably caused by planet-like bodies sweeping out the dust along their orbits. This image, showing in real life what theorists had proposed for years, was surprising, however, because the star, called HL Tau, is only about a million years old—very young by stellar standards.

The ALMA image showed details of the system in the outer portions of the disk, but in the inner portions of the disk, nearest to the young star, the thicker dust is opaque to the short radio wavelengths received by ALMA. To study this region, astronomers turned to the VLA, which receives longer wavelengths. Their VLA images show that region better than any previous studies.

The new VLA images revealed a distinct clump of dust in the inner region of the disk. The clump, the scientists said, contains roughly 3 to 8 times the mass of the Earth.

ALMA image of HL Tau at left; VLA image, showing clump of dust, at right. Credit: Carrasco-Gonzalez, et al.; Bill Saxton, NRAO/AUI/NSF.

"We believe this clump of dust represents the earliest stage in the formation of protoplanets, and this is the first time we've seen that stage," said Thomas Henning, of the Max Planck Institute for Astronomy (MPIA).

"This is an important discovery, because we have not yet been able to observe most stages in the process of planet formation," said Carlos Carrasco-Gonzalez from the Institute of Radio Astronomy and Astrophysics (IRyA) of the National Autonomous University of Mexico (UNAM). "This is quite different from the case of star formation, where, in different objects, we have seen in different stages of their life cycle. With planets, we haven't been so fortunate, so getting a look at this very early stage in planet formation is extremely valuable," he added.

Analysis of the VLA data indicates that the inner region of the disk contains grains as large as one centimeter in diameter. This region, the scientists said, is presumably where Earth-like planets would form, as clumps of dust grow by pulling in material from their surroundings. Eventually, the clumps would gather enough mass to form solid bodies that would continue to grow into planets.

The VLA observations, made in 2014 and 2015, received radio waves with a wavelength of 7 millimeters. The earlier ALMA observations of HL Tau were made at a wavelength of 1 millimeter. The VLA images showed a similar level of detail as the ALMA images.

"These VLA observations are the most sensitive and show the most detail of any yet made of HL Tau's disk at these longer wavelengths," said Claire Chandler, of the National Radio Astronomy Observatory (NRAO). "The VLA's ability to produce such high-quality images in this region is very important to advancing our understanding of these initial stages of ," Chandler added.

The scientists are reporting their findings in the Astrophysical Journal Letters.

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HannesAlfven
1.4 / 5 (11) Mar 17, 2016
So, they found a single good example. But, what about all of those incongruent exoplanetary systems? Not a single mention in this article. Apparently, we can just ignore that which does not fit.
Thirteenth Doctor
5 / 5 (8) Mar 17, 2016
This is awesome. I cant wait to see more images of different young systems as we discover them.
Alfven
1.5 / 5 (15) Mar 17, 2016
Herschel has sent back images of stars forming along filaments all at once. These filaments are also observed to be branching.

This is the problem with this current press release. We are talking about two completely different geometries here, yet some of the researchers appear to be in a state of denial.

If we follow the data where it is leading us, rather than impose the textbook theory upon it, what Herschel is telling us is that stellar formation is often a transient event which quite closely resembles a lightning discharge.

There is likely a parallel going on between small-scale ball lightning and large-scale stellar formation. It does not take a Phd in physics to understand that a conducting plasma filament can exert an ELECTRICAL pull upon the surrounding ions, drawing the neutral matter in with it. In the plasma laboratory, it's called Marklund convection (commonly referred to as an "ion sump").
torbjorn_b_g_larsson
5 / 5 (9) Mar 17, 2016
This is so cool! It also clarifies that the planets are created in the rings, not the gaps as the similar ALMA image of HL Tauri first showed and as was discussed then. [ http://apod.nasa....110.html ]

This reminds me of the crackpot creationist, which like the EU crackpot here, somehow doesn't know what gravity (or a force!) is over on the young star vs habitability thread. They both deny that this is the major formation mechanism, a theory tested yet again.

Next week is the LPSC, I can't wait to see the results! [ http://www.hou.us...psc2016/ ] Oh, I guess I note the same as on the creationist thread, they are welcome to peer review publish their alternate theories in competition. Creationists haven't been able to compete with biology for 2 centuries, and I guess the EU time frame of utter fail is the same. Eventually they die, and their 'ideas' (loosely speaking) dies with them. But science is kept!
wduckss
1.7 / 5 (6) Mar 17, 2016
"Analysis … of the disk contains grains as large as one centimeter in diameter. This region, the scientists said, is presumably where Earth-like planets would form, as clumps of dust grow by pulling in material from their surroundings. Eventually, the clumps would gather enough mass to form solid bodies that would continue to grow into planets."

Nothing new, it can be said (because there are no quotes) that is transcribed from the original (http://www.svemir...ocesses)

"... Growth doesn't stop with atoms; on the contrary, joining goes on. Through joining, chemical reactions and combined, gas, dust, sand, the rocks named asteroids and comets, etc., are all created. Even further, planets are created the same way. Then, when planets grow to the 10% of Sun's mass, they become stars, which can be really gigantic (super-giants). ..."
Nik_2213
3 / 5 (1) Mar 17, 2016
Perhaps not so simple...

Saturn's ring processes suggest that rings with enough density form small moonlets, and such moonlets plough random grains into rings...

Also, perhaps, there's a cascade process when moonlets reach enough mass to begin run-away growth...

Another possibility from looking at that image is those gaps are not swept by direct accretion, but are 'Kirkwood' resonances from unseen planets...

Hmm.
wduckss
1 / 5 (6) Mar 18, 2016
Growth still running slowly, gas, dust, smaller and larger bodies etc. The attractive force is a property of matter and acts on the adjacent particle, body .. etc.
There is no in the center of the gas non-existent gravity that attracts other matter, gravity is the same within each part of the cloud. More substances greater gravity and vice versa.

Unas system growth, we monitor through mergers of smaller bodies with bigger for what the evidence craters on every body.
jualsanpla
2.6 / 5 (5) Mar 18, 2016
Hay decenas de razones que demuestran que la teoría de los planetesimales no es aplicable, PARCIALMENTE, a la formación de los Planetas, dado que no pueden formarse masas iniciales de suficiente entidad.-Por tanto, los Planetas nacen por eyecciones de la Estrella Central,con suficiente masa inicial, eyecciones que se producen especialmente en la etapa T-Tauri, aunque también pueden suceder en cualquier etapa posterior.-Hace poco, el Sol eyectó una masa similar a la de la Tierra, pero sin densidad suficiente para formar un futuro Planeta.-Después de eyecciones de masas suficientes, pueden acrecer las mismas, mediante el proceso planetesimal.-
Un cordial saludo a todos
Thirteenth Doctor
5 / 5 (4) Mar 18, 2016
Growth still running slowly, gas, dust, smaller and larger bodies etc. The attractive force is a property of matter and acts on the adjacent particle, body .. etc.
There is no in the center of the gas non-existent gravity that attracts other matter, gravity is the same within each part of the cloud. More substances greater gravity and vice versa.

Unas system growth, we monitor through mergers of smaller bodies with bigger for what the evidence craters on every body.


You've literally said nothing coherent in this........paragraph. I've read it several times to see if I can get what you mean but its not even a word salad. Its just....what?
wduckss
1 / 5 (1) Mar 18, 2016
jualsanpla

Cráteres que no eyecciones de masa del sol. Ellos aumentar masas cuerpo, poco a poco.
Que viste, Ison, Leónidas y así sucesivamente. Esto significa que el sol se levanta. La gravedad atrae el cuerpo no se expulsa material del cuerpo.
Existen enormes nubes moleculares varios millones sol. Son ellosy ellos eyecciones?
Da Schneib
not rated yet Mar 20, 2016
Fascinating. That ring kinda looks like it's fragmenting into a bunch of blobs, 14 or so of them by my count. The interesting question is, why is it doing that? Is it just the internal dynamics of the ring, or are there other, possibly hidden, masses that are affecting it that way?

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