Astronomy C

[Luo]

For the 2009 test, you want to find out its spectral type (O B A etc) and from there you can approximate its absolute magnitude using an H-R diagram.

Hmmm. Would reading off an H-R Diagram produce an accurate and precise enough reading for the absolute magnitude? When I tried it, my final answer for the distance was on the same order of magnitude as the correct answer, but it wasn't within the allowable range specified in the key. What H-R Diagram are you using? Did you get the correct answer that way?

[Infinity Flat]

For the 2009 test, you want to find out its spectral type (O B A etc) and from there you can approximate its absolute magnitude using an H-R diagram.

Hmmm. Would reading off an H-R Diagram produce an accurate and precise enough reading for the absolute magnitude? When I tried it, my final answer for the distance was on the same order of magnitude as the correct answer, but it wasn't within the allowable range specified in the key. What H-R Diagram are you using? Did you get the correct answer that way?

I haven't actually done the test, but I'd assume then that you need to look into the subclasses, like Of or A1V in order to get into the allowable range.

[Luo]

I haven't actually done the test, but I'd assume then that you need to look into the subclasses, like Of or A1V in order to get into the allowable range.

Yes, I think that's what you might have to do, but it seems to me that pinpointing the exact subclass based on a diagram would be very difficult to do precisely. I wonder what the test writer was intending.

On a separate note, what Astronomy textbooks have people found to be good for this event? I've been using Astronomy: A Self-Teaching Guide, which is clear and concise, but it's definitely not in-depth enough for the material on the Nationals tests.

[Infinity Flat]

I haven't actually done the test, but I'd assume then that you need to look into the subclasses, like Of or A1V in order to get into the allowable range.

Yes, I think that's what you might have to do, but it seems to me that pinpointing the exact subclass based on a diagram would be very difficult to do precisely. I wonder what the test writer was intending.

On a separate note, what Astronomy textbooks have people found to be good for this event? I've been using Astronomy: A Self-Teaching Guide, which is clear and concise, but it's definitely not in-depth enough for the material on the Nationals tests.

I've been using Carrol / Ostlie's Introduction to Modern Astrophysics (2nd Edition).
It's a VERY strong text, and has a good balance have math and concepts.

[Infinity Flat]

Not sure if anyone else has seen this, but a lot of the worksheets here are really good if you want to work on the math.

[QuantumLeaper]

Thank you, Infinity. These look awesome.

[Infinity Flat]

11th at nationals, woot! A lot better than I was expecting, and I really enjoyed doing the test. Pacing was key, as was skipping questions you just didn't know / have time to look at. Learned my lesson from diseases earlier that morning

[salcedam]

What are some good textbooks to use to study over the summer?

[Infinity Flat]

What are some good textbooks to use to study over the summer?

For some basic stuff, http://www.astronomynotes.com

For more advanced, Carrol & Ostlie's Introduction to Modern Astrophysics.

[salcedam]

What are some good textbooks to use to study over the summer?

For some basic stuff, http://www.astronomynotes.com

For more advanced, Carrol & Ostlie's Introduction to Modern Astrophysics.

Thanks! Do you have any tips for studying the DSO's (once the list comes out)?