- #351
schwarzchildradius
Here's my guess:
Humason & Hubble,
Mt. Wilson Palomar observatory
1923
(andromeda is moving towards us)
correct?
Humason & Hubble,
Mt. Wilson Palomar observatory
1923
(andromeda is moving towards us)
correct?
No, none were correct except for the fact that Andromeda (galaxy) is moving towards us.Originally posted by schwarzchildradius
Here's my guess:
Humason & Hubble,
Mt. Wilson Palomar observatory
1923
(andromeda is moving towards us)
correct?
Where is correct and when is very close, but a tiny bit off...Originally posted by Lonewolf
Vesto Melvin Slipher in 1912. Not sure where.
Lowell Observatory, Flagstaff, Arizona.
That is certainly close enough to be CORRECT! Actually, the first redshift measurement results were determined in 1913.Originally posted by Lonewolf
He began the observations in 1909, but didn't make the observation until 1912.
if you've got more details about how that's done, I'd love to hear about it.
Originally posted by schwarzchildradius on August 20
what's the mass and atmospheric content of the star Sirius?
Originally posted by marcus
that question has been sitting out there for a couple of days
anyone care to answer?
what's the mass and atmospheric content of the star Sirius?
Yes, I realize that, but Schwartzchild's original answer to your question included: "It's used to measure masses and atmospheric content of stars."Originally posted by Lonewolf
I think you're confused. The interferometry question was mine, which Schwarzschildradius answered. Schwarzschild's question was:
Originally posted by Labguy
But, the original question at hand was about an interferometer, and interferometers don't have squat to do with measuring a star's atmospheric content. They do that with spectrometers / spectrographs.
No, it is not my turn. I never answered the question at all. Your quote given above that "(it increases resolution so you see greater detail, two telescopes some distance apart are linked so they act in a certain way like a larger telescope with more resolving power)" was given by someone else, not me!Originally posted by marcus
Would this work as a way out.
Lonewolf asked about interferometry and Labguy finally gave the correct answer (it increases resolution so you see greater detail, two telescopes some distance apart are linked so they act in a certain way like a larger telescope with more resolving power)
so it is now Labguy's turn
that seems logical to me, how does it seem to you Lonewolf
meanwhile Schw. Radius answered a different question "what is spectroscopy?" (it is a way to tell atmospheric composition by spectrum of light and can be used to infer the mass under certain assumptions)
And Schw. should be happy because he got a "free turn" and asked about Sirius and I answered his question. But we rescind that little digression and Labguy goes.
Marcus' turn. He just asked one bottom of previous page.Originally posted by Lonewolf
Ah, ok. Sorry for the mix up, Labguy. I accepted it as an indirect application of interferometry. I was after more what we can use it for than what it does. We can perform spectroscopy on the signal we obtained from the interferometer, and thus obtain atmospheric content. It may seem a dubious decision, but I thought it'd be best to try and get some momentum going on the thread.
Whose turn is it now, then?
Originally posted by Lonewolf
So he did. I must have missed that.
Let A be the dimmer star and B be the brighter star.
Using the equation
mB - mA = 2.5 log 10 (IA/IB)
We cab obtain 10(mB - mA)/2.5 = IA/IB
From the question, we know mB - mA = 1. so
101/2.5 = 2.512 (approximate) = IA/IB
or 2.512*IB = IA
Hence, B is approximately 2.512 times as intense as star A. If we multiply both sides of the equation by 1 square meter, we are left with units of power. Hence, their wattages differ by approximately a factor of 2.512.
Ok, another easy "Star" question.Originally posted by Lonewolf
That was indeed what I was thinking, Labguy, Your turn.
Originally posted by Labguy
Ok, another easy "Star" question.
In not too many words, why do lower mass stars have radiative cores and convetive outer layers, while massive stars have convective cores and radiative outer layers??
All this is sub-photosphere, of course.
Good guess. That's it, 100%.Originally posted by LURCH
Just a geusse;
The more massive stars are denser, rendering normal raditation impossible near the core. So heat from the core is transported via convection to the outer layers, where density is lower (closer to the density of the Sun's inner layers), and radiative heat transfer can occur?