Recent content by Phigla

Hi, To try to understand this process I tried to make an exercise with an imaginary molecular cloud Under is the way I thought to use for that Initial molecular cloud: Mass M0, Density ρ0 = μnmH, Temp. T 1. I compute R0, V0, initial radius and volume considering a spherical molecular cloud...

Dear Astronuc, Thanks for your reply trying to help me for the understanding of the collapse and fragmentation of a molecular cloud leading to proto-star. Everything started when I read an article on the internet ( I attach illustration of this article) and this lead me to search for the process...

Dear Masher, Thanks trying to help me. Since I posted this thread I did not made a lot of progress and I'm still stuck with the fragmentation step. I hope the light will come soon. You are the only one having sent me few words, Thanks for that

Good morning, I continue to try to understand the collapse and fragmentation of a molecular cloud. I was focused on the Jeans law. I would like, now to understand the difference between this Jeans law and the Bonnar-Ebert model. Are they complementary ? Thanks for your help

I make progress, with the mass of Jeans, MJ= Cst1 x square root of T3/Rho Rj= square root of Cst2 x T/number of atoms per m3 in the cloud. So what understands is that if a molecular cloud collapses it will reach this mass and this radius. As the radius decreases, so the volume decreases and...

Dear Bandersnatch, Thanks for your reply. I try to go step by step In a typical molecular cloud, the mean temperature of this cloud is 15-20 K, density few hundred particles per cubic centimeters, but inside some regions have clumps with density much higher 1000-10,000 particles per cubic...

Good morning, I read on the internet that a molecular cloud contains denser part, I also read that a molecular cloud start to collapse according the Jeans law If it's the full cloud collapsing what is happening to these denser parts ? and after collapsing how the fragmentation occurs ? In fact...

Dear All, Thanks a lot for your help, I am sorry to reply so late...the time for me to digest what you sent me. On the mean time, I have another question not related to Cepheids. Reading what I can read, I saw that Vega is the star reference for the apparent magnitude (even if it is 0.03) and...

Thanks. To tell you, I am retired (i'm 70) in China...and Wikipedia and other sites is blocked by the authorities, are so my source of information is limited. Concerning the Cepheid it is said that all Cepheid with a certain period are assumed to have the same absolute magnitude. Measuring the...

Good morning, I don't understand how the Cepheid variables are used to measure the distance of Stars. Is a member is patient to explain to me thanks

Good morning My name is Philippe, I'm retired and since few months interested to physics related to space. My back ground is limited, let's say self learning about this topic. I discovered your forum and I registered. I hope not to bother you with trivial questions. Thanks in advance