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Re: Astronomy C

Posted: September 12th, 2019, 8:09 am
by Name
seitanBacon wrote: September 12th, 2019, 6:45 am Is Chandra going to post videos this year/is NASA sponsoring the event again?
NASA is sponsoring. Last year I think Chandra posted videos in like January so even if they do, it might be a while.

Re: Astronomy C

Posted: September 12th, 2019, 8:53 am
by pb5754
Name wrote: September 12th, 2019, 8:09 am
seitanBacon wrote: September 12th, 2019, 6:45 am Is Chandra going to post videos this year/is NASA sponsoring the event again?
NASA is sponsoring. Last year I think Chandra posted videos in like January so even if they do, it might be a while.
Last year they were posted in October, so just wait like a month-ish.

Re: Astronomy C

Posted: September 22nd, 2019, 6:46 am
by AstroGuyVlogs
What is a good place to learn and practice calculation problems? I have an introduction to astrophysics book but it more in-depth and has a lot of calculus.

Re: Astronomy C

Posted: September 23rd, 2019, 5:44 am
by seitanBacon
AstroGuyVlogs wrote: September 22nd, 2019, 6:46 am What is a good place to learn and practice calculation problems? I have an introduction to astrophysics book but it more in-depth and has a lot of calculus.
I've used astronomynotes.com in the past to get general foundations and then just look at past tests and solve some of those

Re: Astronomy C

Posted: September 23rd, 2019, 6:37 pm
by Blank25
freed2003 wrote: September 4th, 2019, 9:02 pm Is cheating really prominent in this event? My friend told me at regionals he saw many people going online, which is believable since our region isn't too serious. Howeverl, he said he even saw cheating at the state level(I live in Socal). Is it really that bad?
When I was a freshman, someone on a lower team admitted to cheating on the Astronomy test at regionals by looking up stuff on Wikipedia.So, it's definitely a problem. But they kinda still sucked and still got second last. oof

Re: Astronomy C

Posted: October 3rd, 2019, 2:34 pm
by Techsam
AstroGuyVlogs wrote: September 22nd, 2019, 6:46 am What is a good place to learn and practice calculation problems? I have an introduction to astrophysics book but it more in-depth and has a lot of calculus.
If you want a good in-depth place to get lots of practice with Astrophysics, the textbook An Introduction to Modern Astrophysics by Bradley W. Carroll and Dale A. Ostlie (a.k.a BOB - Big Orange Book) is a great resource. It might be a bit of an investment, but since Astronomy is an event every year it could be worthwhile for you/your team to invest in getting it.

Re: Astronomy C

Posted: October 3rd, 2019, 6:20 pm
by Techsam
pb5754[] wrote: September 5th, 2019, 12:48 pm
Unome wrote: September 5th, 2019, 7:21 am
Name wrote: September 4th, 2019, 10:10 pm
What even is JS9 meant for? How would test writers make questions using JS9? How should we study for JS9 questions?
It's for image analysis. I don't know too much more than that. Should be pretty straightforward for the most part honestly.
Agreed... most of the JS9 questions were pretty basic and a lot of them were pretty much just common sense, although they might be a bit more in depth with the new rules ig.

To shed some light on this topic, JS9 like you all mentioned is used for image analysis. Generally questions are like you said 'straightforward' since working with new software can be difficult. At the start of the examination you should be given a .FITS file from which to gather data from using JS9 tools (e.g. Energy Spectrum) and from that you will have to answer questions based on your observations. This is to make the examination more hands on with actual astronomic data and analysis.

There is a tutorial/user guide available for JS9 on their website. For more information you can also search for DS9 (http://ds9.si.edu/site/Home.html) which is a similar tool, but is not built as a webapp as JS9, instead you must download it. There is an online MOOC (Massive Open Online Course) run by a Professor Terry Matilsky on Coursera call Analyzing the Universe which can show you how to use this tool for analysis of astronomical data.

Re: Astronomy C

Posted: October 17th, 2019, 6:39 pm
by eatablechief21
Does anyone have any images for H1821+643 and NGC 2623.I got like one or two for them, but I couldn't find any more. I'm new to Astro so I need some help on it.

Re: Astronomy C

Posted: October 18th, 2019, 5:29 pm
by hippo9
So for calculating recessional velocity from redshift I've found 2 different equations:

The far simpler z=v/c
As well as the more complicated (v/c)= ((z+1)^2-1)/((z+1^2+1)
Sorry that looks bad.

Which one is correct then? Or are they for different situations that I'm oblivious to?

Re: Astronomy C

Posted: October 18th, 2019, 5:51 pm
by syo_astro
eatablechief21 wrote: Does anyone have any images for H1821+643 and NGC 2623.I got like one or two for them, but I couldn't find any more. I'm new to Astro so I need some help on it.
Some DSOs may just not have many images. One thing you can do is to google search for "DSO name" with a specific observatory or website from past soinc.org webinars (on the soinc.org astro page there are webinars for beginners!). For example, search "NGC 2623 X-ray", "DSO Chandra observatory" or "DSO APOD", etc. You can also stock up on graphs that show up, though they can come from research papers and be too difficult when starting out. Usually even after collecting the major images, there's plenty of work to do organizing and studying info. Others feel free to chime in!
hippo9 wrote: October 18th, 2019, 5:29 pm So for calculating recessional velocity from redshift I've found 2 different equations:

The far simpler z=v/c
As well as the more complicated (v/c)= ((z+1)^2-1)/((z+1^2+1)
Sorry that looks bad.

Which one is correct then? Or are they for different situations that I'm oblivious to?
Yup, they're used in different situations! The simpler form is used at "low" velocities (specifically: non-relativistic), while the other form is more general (called "relativistic Doppler shift"). hippo9 also asked on chat why on some people use "z=v/c" vs. "z=~v/c" (implying the equality exact or approximate). I think if people use "=", they are saying it's an approximation but "basically the same", so it's fair to say that "=". Need a more detailed proof, or does that suffice? Practically speaking, you just have to be on lookout for whether something is explicitly or implicitly stated to be at relativistic speeds.