Survey of protoplanetary disks finds their size varies significantly
Click for original image.
A survey of the protoplanetary disks in a star-forming region about 400 light years from Earth has found that the size of the disks can vary considerably, with many much smaller than our own solar system.
Using ALMA [Atacama Large Millimeter/submillimeter Array in Chile], the researchers imaged all known protoplanetary discs around young stars in Lupus, a star forming region located about 400 light years from Earth in the southern constellation Lupus. The survey reveals that two-thirds of the 73 discs are small, with an average radius of six astronomical units, this is about the orbit of Jupiter. The smallest disc found was only 0.6 astronomical units in radius, smaller than the orbit of Earth.
…The small discs were primarily found around low-mass stars, with a mass between 10 and 50 percent of the mass of our Sun. This is the most common type of star found in the universe.
You can read the research paper here [pdf]. The image to the right, figure 1 from the paper, shows 71 of those disks, with two-thirds clearly much smaller than our solar system.
Because exoplanet surveys have found many small exoplanets around low-mass stars, this new data suggests that planets can also form from these small accretion disks, and that planet formation is also ubiquitous throughout the universe.
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Click for original image.
A survey of the protoplanetary disks in a star-forming region about 400 light years from Earth has found that the size of the disks can vary considerably, with many much smaller than our own solar system.
Using ALMA [Atacama Large Millimeter/submillimeter Array in Chile], the researchers imaged all known protoplanetary discs around young stars in Lupus, a star forming region located about 400 light years from Earth in the southern constellation Lupus. The survey reveals that two-thirds of the 73 discs are small, with an average radius of six astronomical units, this is about the orbit of Jupiter. The smallest disc found was only 0.6 astronomical units in radius, smaller than the orbit of Earth.
…The small discs were primarily found around low-mass stars, with a mass between 10 and 50 percent of the mass of our Sun. This is the most common type of star found in the universe.
You can read the research paper here [pdf]. The image to the right, figure 1 from the paper, shows 71 of those disks, with two-thirds clearly much smaller than our solar system.
Because exoplanet surveys have found many small exoplanets around low-mass stars, this new data suggests that planets can also form from these small accretion disks, and that planet formation is also ubiquitous throughout the universe.
Readers!
My annual February birthday fund-raising drive for Behind the Black is now over. Thank you to everyone who donated or subscribed. While not a record-setter, the donations were more than sufficient and slightly above average.
As I have said many times before, I can’t express what it means to me to get such support, especially as no one is required to pay anything to read my work. Thank you all again!
For those readers who like my work here at Behind the Black and haven't contributed so far, please consider donating or subscribing. My analysis of space, politics, and culture, taken from the perspective of an historian, is almost always on the money and ahead of the game. For example, in 2020 I correctly predicted that the COVID panic was unnecessary, that the virus was apparently simply a variation of the flu, that masks were not simply pointless but if worn incorrectly were a health threat, that the lockdowns were a disaster and did nothing to stop the spread of COVID. Every one of those 2020 conclusions has turned out right.
Your help allows me to do this kind of intelligent analysis. I take no advertising or sponsors, so my reporting isn't influenced by donations by established space or drug companies. Instead, I rely entirely on donations and subscriptions from my readers, which gives me the freedom to write what I think, unencumbered by outside influences.
You can support me either by giving a one-time contribution or a regular subscription. There are four ways of doing so:
1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.
2. Patreon: Go to my website there and pick one of five monthly subscription amounts, or by making a one-time donation.
3. A Paypal Donation or subscription:
4. Donate by check, payable to Robert Zimmerman and mailed to
Behind The Black
c/o Robert Zimmerman
P.O.Box 1262
Cortaro, AZ 85652
You can also support me by buying one of my books, as noted in the boxes interspersed throughout the webpage or shown in the menu above.
I still remember the close-stellar-approach theory of planetary formation being taught in 5th grade science class. In this theory a filament of matter was drawn from the stars and coalesced into planets around one or both of them. In fact, this seemed to be the only theory taught!
My teacher, Mr. Pulaski, was a WWII vet, and was mightily impressed that I knew what the U in U-boat meant, and said it in German (unterzee). When I said that this theory meant that planets would be almost non-existent, he admonished me about the laws of.very large numbers: anything that CAN happen, WILL happen… and it will happen a lot! Never forgot that.