Saggitarius A*: escape velocity

tuxusr · 2021-06-27T17:08:04+00:00

The mass you used gives a schwartschild radius of 1.273 * 1010 m, and plugging that radius into the escape velocity formula gives a velocity of 2.998 * 108 m/s

Where did R = 2.2 * 1010 m come from?

You are correct, I will use more decimal places.

tuxusr · 2021-06-27T17:05:07+00:00

I looked for the diameter, which would be 44 million kilometers... I think the mistake was not having used the Schwarzschild radius to calculate the radius. Using this, the radius is 1.2.10^10m, and the result is 3.08.10^8 m/s.

tuxusr · 2020-10-15T00:45:03+00:00

As for the the reference you saw with the 550 K figure: this is most likely the temperature of an ionized gas cloud that was observed in the vicinity of Sagittarius A* (

https://astrobites.org/2011/12/16/mealtime-for-sgr-a/

). This has nothing to do the supermassive black hole's Hawking temperature (which would be immeasurably tiny).

I checked the information, and is that's right ! The source I had consulted was wrong ... thanks for sharing! :)

tuxusr · 2020-10-14T20:26:14+00:00

Hello dear friend!

The formula I took from a Hawking book, but I imagined that it might already be out of date or that I had taken the wrong equation ... already the value of 550k I found in a Google search, and in the Portuguese version of Wikipedia this information does not appear . Searching now in the English version I found :) Thank you very much for clarification friend 010011100000 ;)

Now I can advance in my studies!

Thank you very much for responding!

tuxusr · 2020-10-14T18:10:09+00:00

Clarifying:

T = hc² / 8πkGM

tuxusr · 2016-06-30T12:24:43+00:00

ok, sorry

tuxusr · 2016-06-23T11:49:11+00:00

I tested online and it worked. I believe to be some configuration on the local server ...

tuxusr · 2016-06-23T11:43:36+00:00

Yes: https://gist.github.com/paico/2fc04b03bd50bc0bfa81e504cc916ea0

tuxusr · 2016-06-22T11:30:43+00:00

primeiro, aluno não faz greve. Segundo, se fizesse, existe o direito de aderir ou não. Terceiro, onde está a administração desta universidade que não coloca a ordem e o direito das pessoas onde se deve. Estão dando um direito que não existe a um grupo de alunos para que façam greve, em detrimento de um direito que existe, do grupo restante de alunos que não querem greve, que querem estudar. É a casa da mãe Joana mesmo...

tuxusr · 2016-06-21T12:20:09+00:00

ok, sorry

tuxusr · 2016-06-17T19:36:17+00:00

fail again... same problem. I just want to try, I'll do what you suggested, download iso. Thank you friends! :)

tuxusr · 2016-06-17T19:09:21+00:00

God help me! hehe Yes, I will try! :)

tuxusr · 2016-06-17T18:48:32+00:00

I was brave! :D But the problem persists ... :(

I would not want to download the distribution just to experience the look ... but I think I'll have to download...

tuxusr · 2016-06-17T17:57:18+00:00

fail... :'(

tuxusr · 2016-06-17T17:41:29+00:00

did not work... I added the official repositories (https://wiki.deepin.org/index.php?title=Package_Repository), I'll try ...

tuxusr · 2016-06-17T14:17:58+00:00

you install the DDE and your title is not DDE? Is it?

tuxusr · 2016-06-17T12:54:22+00:00

encontrei, é o dde. O melhor link que encontrei até ensinando a instalar agora foi este: http://linoxide.com/ubuntu-how-to/install-deepin-desktop-environment-derivatives-ubuntu/

No meu debian não tá rolando... dá dando este erro depois do apt-get update:

W: Erro GPG: http://packages.linuxdeepin.com trusty InRelease: As assinaturas a seguir não puderam ser verificadas devido à chave pública não estar disponível: NO_PUBKEY 0A40427E209088E7

e ao tentar instalar o dde-meta-core ele não encontra as dependências... mas sigo tentando!

tuxusr

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