Astronomy C

[syo_astro]

Hmm, when competing I think I only ever learned about Roche lobes, Lagrange points, etc conceptually. Admittedly, fun might be fun, though .

On the side about testing, calculating a Lagrange point doesn't look like a great problem for testing (more because it just seems like plug and chug). Though, there's always a way (the classic simplify complicated/plug and chug problem into parts and make it more interesting/testing skills better).

[Unome]

Question: how would I go about learning stellar evolution? Right now my knowledge is very fragmented, and I end up missing a lot of it on tests.

[jonboyage]

Hmm, when competing I think I only ever learned about Roche lobes, Lagrange points, etc conceptually. Admittedly, fun might be fun, though .

On the side about testing, calculating a Lagrange point doesn't look like a great problem for testing (more because it just seems like plug and chug). Though, there's always a way (the classic simplify complicated/plug and chug problem into parts and make it more interesting/testing skills better).

In one of the competitions I went to this year they asked me to calculate the distance between the two stars, so I wanted to find out how I would go about doing that.

Question: how would I go about learning stellar evolution? Right now my knowledge is very fragmented, and I end up missing a lot of it on tests.

I would recommend getting a textbook such as Astronomy Today and reading the chapters on stellar evolution. That would give you a great baseline off of which you can build your knowledge of stellar evolution. If you are not able to afford a textbook, just go online and find each stage of stellar evolution and research specifically about each stage individually and how the star transitions between each one.

[Magikarpmaster629]

Question: how would I go about learning stellar evolution? Right now my knowledge is very fragmented, and I end up missing a lot of it on tests.

http://www.atnf.csiro.au/outreach//educ ... ontop.html
I recommend this website for stellar evolution; also has other good astronomy resources.

[syo_astro]

For learning stellar evolution:
Indeed, collecting info from different sources and condensing it into a process helps. Also, I used to use the DSOs and order them by evolution (very useful for tests too ).

For distance between two stars:
It depends on the problem, but it shouldn't have to do with Lagrange points, right? Normally it's a binary or something with small angle formula as I recall, no?

[Magikarpmaster629]

Hmm...I'm having trouble figuring out what math I need to know, besides the usual Kepler's Laws, light-related equations (Wien's Law, doppler shift, etc.), distance equations (parallax, distance modulus). I think I've seen age of a cluster from an HR diagram, but that's pretty simple. Last year we had all this stuff related to detecting exoplanets, like an equation to find the radius of a transiting exoplanet or the mass of an exoplanet from its radial velocity. I guess those both can be done with binary stars as well, but is there anything else I should know how to calculate? Specifically related to SN Ia, white dwarfs, or accretion disks?

[Adi1008]

Hmm...I'm having trouble figuring out what math I need to know, besides the usual Kepler's Laws, light-related equations (Wien's Law, doppler shift, etc.), distance equations (parallax, distance modulus). I think I've seen age of a cluster from an HR diagram, but that's pretty simple. Last year we had all this stuff related to detecting exoplanets, like an equation to find the radius of a transiting exoplanet or the mass of an exoplanet from its radial velocity. I guess those both can be done with binary stars as well, but is there anything else I should know how to calculate? Specifically related to SN Ia, white dwarfs, or accretion disks?

Last year they had some really cool stuff with gas clouds and SEDs too!!!!!!!!! In addition to what you said, maybe some Hubble's Law stuff, but that stuff is pretty straightforward. I think you won't see much math in isolation, but rather, embedded within harder, more complex questions that test tough concepts. There, the math itself won't be hard, but figuring out the concepts behind it will be

Also, pretty random, but what was the first white dwarf to be discovered? It won't really help on a test in scioly, since it's just trivia; I'm just curious. I've seen a variety of sources say it's 40 Eridani B, while other sources say it's Sirius B. 40 Eridani B was discovered in 1783 and astronomers figured out it was a white dwarf in 1910. Sirius B was discovered in 1844 through calculations and astronomers figured out it was a white dwarf in 1915 (all this information is straight off Wikipedia). However, a lot of websites (such as http://whitedwarf.org/education/ask/index.html#3) say it's Sirius B. What would cause the discrepancy?

[antoine_ego]

Could it be that 40 Eridani B was only officially described by Walter Adams in 1914, while Sirius B was found to be a white dwarf in 1915, and the difference in dates is so small people got confused?

Truthfully my guess is that it's much easier to remember that Sirius had the first white dwarf than Eridani.

[syo_astro]

Last year they had some really cool stuff with gas clouds and SEDs too!!!!!!!!!

I appreciate the excitement, I spent a lot of time on those questions (along with some others I imagine). Also, what you say is exactly right. None of the math itself is supposed to be impossible. Test writers really can't use calculus/advanced math much, and a lot of ideas rely on fundamentals anyway. Really the process of simplifying complicated problems using our simple equations is itself the real challenge (at least for me that's what I try).

One of the funny things about exoplanets you (Karp) bring up is that a lot of those methods are actually reapplications of knowledge from various other areas (light curves and eclipsing binaries, radial velocity and Kepler's laws same deal). Of course, there's lots of novel methods with exoplanets (especially with atmospheres they've done a ton), but there are plenty of methods that have extreme amounts of research and depth with stars. But then I am biased. Need to save some question ideas!

[Unome]

Internet is not helping.I think it has to do with Kepler's third law, but I can't figure out how to get the distance.