Re: APOD: Stardust in Aries (2017 Dec 09)
Posted: Thu Jan 04, 2018 2:50 am
Bruce,BDanielMayfield wrote:Thanks for your reply Sally, and may you be happy too. And for amending and clarifying your claims re CX330. I also enjoyed reading the reference from TTU, which shows that more than just UT and TAMU are doing cutting-edge astronomy.sallyseaver wrote:Hi Bruce,BDanielMayfield wrote:Hello Sally. I think you've made some valid points in questioning conventional wisdom re star formation, especially in areas like the vacinity of Sag A*. However, at least twice in this thread you have claimed that the young star object CX330 changed from a black hole into a protostellar object. Can you provide any support for this claim?
Bruce
First of all, thank you VERY much for considering my debate points and providing consideration even though they are not in a peer-reviewed article.
Thank you for the opportunity to clarify about CX330. I should not have said "black hole". The original observation in 2009 was the detection of an x-ray source. And it's true that x-ray sources are seen as potential candidates for black holes among space scientists, but it is not a confirmed black hole. It was observed giving off some light in additional observations. Then based on data from NASA’s Wide-field Infrared Survey Explorer (WISE) in 2010, the researchers saw that this object had quite a lot of warm dust around it. The research team that has reported on this does NOT see it as discrediting the standard model. They say that it is unusual for being born in a region where there are not other young stars being born. I am the one saying that going from no infrared presence in 2007 to a dust disk with infrared presence in 2010 is contradictory to the standard model.
The research team is from Texas Tech University
http://today.ttu.edu/posts/2016/07/new-star#prettyPhoto
Best regards and Happy New Year,
Sally
Yes, the protostar ? CX330 did show a remarkable outburst of infrared light over a short period, and it is in a location far from other star forming regions. However, conditions can change rapidly as the collapse of gas in free fall heats up and as radiation from a protostar burns and/or blows openings in its surrounding dust cloud. I would have to agree with the TTU astronomers; this object doesn't 'discredit the standard model' as you put it.
However, to be fair, upon reflection this object doesn't discredit your model either. But, to be honest, I think other facts do.
Bruce
I hear you. I understand your response to the TTU online article. Since they are not saying that the rapid appearance of the protostar is contrary to conventional gravitational collapse models of star formation, it can fit within the usual thinking about gravitational collapse.
According to Wikipedia on Star Formation: "During the collapse, the density of the cloud increases towards the center and thus the middle region becomes optically opaque first. This occurs when the density is about 10^−13 g / cm^3." So the expectation is that the center becomes more dense first, pretty early on, and that heat and radiation will be coming from this center region. I believe that this model for star formation is thought to take millions of years.
The CX330 team called the infrared image of a star in the 2010 image an outburst.
1. What did it burst out from? There was no indication of a star at all in the 2007 image (except for an x-ray source)?
2. I think you will find that a protostar region of gas "in free fall" that has no infrared presence would not be generating x-rays, as in the 2007 image. (However, X-rays are seen as candidates for black holes*)
Perhaps I'll see if the research team will field these questions.
Sally
* http://hyperphysics.phy-astr.gsu.edu/hb ... lkbin.html, Cygnus X-1 article and confirmation by a professional space scientist with the Air Force