sorry about the hide function, I tried to use the command but it didn't work. I'll try and fix it.
Ok, at what temperature does a protostar become classified as a T-Tauri star? This sets it on what path on an HR Diagram?
Re: Astronomy C Question Marathon
Posted: September 10th, 2013, 10:17 am
by foreverphysics
Above 3,000 K (burning deuterium before this) but below 100 million K (the temperature required for fusion to start), and sets it on track for main sequence.
[size=10]Disclaimer: I haven't studied stellar evolution since May, so this is just from memory. Don't kill me if I'm wrong.[/size]
Re: Astronomy C Question Marathon
Posted: September 11th, 2013, 12:15 pm
by bbgun34
[hide]That's gonna be 6740.33 F (or 4000 K, but you know) and it'll be on the Hayashi track. [/hide]
(Yeah so my hide apparently doesn't work either)
So what DSO is this, and what's the absolute magnitude of that bright star in the middle?
Re: Astronomy C Question Marathon
Posted: September 11th, 2013, 2:52 pm
by alpacas
ngc3132, the star in the image is about absolute magnitude 0.3 (at least the progenitor star is)
Edit: sorry people I am having major technical difficulties with my "hide" function so I'm just writing the answer out for the sake of transparency
Re: Astronomy C Question Marathon
Posted: September 11th, 2013, 8:38 pm
by FawnOnyx
alpacas wrote:
Edit: sorry people I am having major technical difficulties with my "hide" function so I'm just writing the answer out for the sake of transparency
I think you guys need a "|" character delimiter inbetween the hide tags to separate the heading of the hide block from the actual hidden content.
Example: [ hide]Hide Heading|Hide content[/hide] (without the first space displays:
Hide content
Re: Astronomy C Question Marathon
Posted: September 13th, 2013, 10:08 pm
by bbgun34
Alrighty I guess I'll put up another question k peeps:
So there's this one early-age main-sequence star, Del B7730, with absolute magnitude 4.6 and apparent magnitude 10.2. Suppose you were (magically) able to line up a bunch of one-inch (diameter) strawberry gum-balls (melt-resistant, totally a thing) from the sun to this star. If the total mass of these gum-balls is equal to the mass of B7730, what is the density, in kg/m^3, of one of these gum-balls? How many times (orders of magnitude) more or less is this than the density of a white dwarf and that of a neutron star?
Re: Astronomy C Question Marathon
Posted: September 14th, 2013, 12:23 pm
by alpacas
density~1.92x10^14 kg/m^3
making them 10^5 x denser than white dwarfs, and 10^-3 x the density of neutron stars
hopefully. I hope you didn't want the distance to be measured trying to take into account the radius of Del b7730 ;) and the sun because well I didn't
Re: Astronomy C Question Marathon
Posted: September 14th, 2013, 10:22 pm
by bbgun34
Well yeah, disregarding radius, but I'm getting 1.79x10^15 kg/m^3.
Anyone else have any ideas?
But in the meantime maybe I'll post a more mellow problem:
A huge 4000-Kelvin tomato behaves like a blackbody. If Larcie Curbh, the astronomer observing this cosmic tomato, gets sick if she sees anything with a wavelength of at most 7000 Angstroms, what must the radial velocity of this tomato be (and in which direction) so that Larcie gets sick?
Re: Astronomy C Question Marathon
Posted: September 15th, 2013, 2:49 pm
by alpacas
1.1x10^7 m/s away from "Larcie"
Re: Astronomy C Question Marathon
Posted: September 18th, 2013, 9:27 pm
by imafish
alpacas wrote:ngc3132, the star in the image is about absolute magnitude 0.3 (at least the progenitor star is)
Edit: sorry people I am having major technical difficulties with my "hide" function so I'm just writing the answer out for the sake of transparency
Hi,
How did you get absolute magnitude 0.3? Is it a given research number?
I'm still new to this event so I'm compiling resources right now.
Currently I know NGC 3132 is 550 pc away, and the brighter star has an apparent magnitude of 9.87
Using the distance modulus M-m=5-5log(d) > M=5-5log(550)+9.87 = 1.17
which is totally off...
Please help me! Thank you
