Astronomy C

[Adi1008]

Astronomy C: Teams will demonstrate an understanding of Star and Galaxy Formation and Evolution.

Astronomy Wiki

Astronomy Test Exchange 2020

Past Threads: 2009 (Variable Stars), 2010 (Galaxies), 2011 (AGNs), 2012 (Stellar Evolution & Type Ia Supernovae), 2013 (Stellar Evolution & Type II Supernovae), 2014 (Variable Stars & Stellar Evolution), 2015 (Star & Planet Formation), 2016 (Star Formation & Exoplanets), 2017 (Type Ia Supernova Events), 2018 (Type II Supernova Events), 2019 (Galaxies), 2020 (Galaxies and Cosmology)

Past Question Marathons: 2014, 2015, 2016, 2017, 2018, 2019, 2020

[AstroClarinet]

Differences from last year:
-A new DSO, DLA0817g, has been added
-2 surveys, the Chandra Isotropic Universe Survey and the Hubble CANDELS Survey, have been added in addition to the DSOs
-The 3 Quasars have been removed

It seemed weird that they were adding surveys to the DSO list at first, but they are pretty similar because the DSOs were already focusing on studies. Now the test writers can focus more on the actually findings of the studies rather than relatively unimportant features of the DSOs.

[OrigamiPlanet]

Are there any images on the surveys or any of the PSS objects?

[pb5754]

Are there any images on the surveys or any of the PSS objects?

The PSS objects don't have a lot of images, but there are a few on Chandra, etc. Haven't down much research at all on the surveys yet (wasting my time procrastinating on college apps ), but I believe the same applies for those as well.

[astronomybuff]

To bring attention to it, the Astronomy Formula Sheet on the wiki has been updated. If you catch any errors, feel free to correct them yourself or let me know and I'll correct the original file.

[Fyren]

Anyone have recommendations on resources for learning the material in the rules and good sources for notes? This is my first year competing in Astronomy and I don't really have any background information on the event material, so I really just need good sources to help me get started with learning and preparing. Tips are also very appreciated.
(Also, I think I should say that I will be posting on here quite a bit with questions...)

[AstroClarinet]

Anyone have recommendations on resources for learning the material in the rules and good sources for notes? This is my first year competing in Astronomy and I don't really have any background information on the event material, so I really just need good sources to help me get started with learning and preparing. Tips are also very appreciated.
(Also, I think I should say that I will be posting on here quite a bit with questions...)

On previous year's threads, a good number of sources have already been listed. Here's a summary (there are pretty much the same as what I use):
Basic info
-astronomynotes.com - a good first resource for basic understanding
-HyperPhysics - more math-oriented
-Various textbooks - "An Introduction to Modern Astrophysics 2e" by Carroll & Ostlie has been suggested multiple times
-Online astronomy college course lectures - have to look around online for these

DSOs
-Chandra website photo album & press releases - gives a description of most DSOs & has a good number of images for each. Also has observation IDs if you want to use the observation images as practice for JS9, and links to the scientific papers.
-Wikipedia - has basic info on the DSOs Chandra doesn't cover.
-Scientific papers - on arXiv, IOPscience etc; these provide more in-depth images/numbers/info. You can probably skip these on your first pass through researching DSOs and come back to them later.
-SIMBAD & NED (NASA/IPAC Extragalactic Database) - have data & alternate names for most DSOs. You might have to change the name of the DSO a little bit when you're searching for it so that it shows up.
-APOD - for images

[RobertYL]

Some JS9 Stuff:
Recently (in the past month or two sometime, not entirely sure when), the UnOfficial Chandra Archive, one of the main places for getting FITS files to analyze with JS9, stopped properly working. As it turns out, this is a result of Chandra actually moving the folder where their archive is, so the Archive links no longer lead anywhere. The result as it relates to Science Olympiad? The main image archive used for JS9 image analysis is now not properly functioning and many of the links used for JS9 images on previous tests will not directly work either.

Fortunately, there is a fix that works well enough for now.

The Quick Method: For Links From Old Tests:
The format of a link coming from old tests (for the image with ObsID of 2000) looks like this:

Code: Select all

ftp://cda.harvard.edu/pub/science/ao02/cat5/2000/primary/acisf02000N004_evt2.fits.gz/

The new format of the link (for the image with ObsID of 2000) looks like this:

Code: Select all

https://cxc.cfa.harvard.edu/cdaftp/science/ao02/cat5/2000/primary/acisf02000N004_evt2.fits.gz/

So, you can just replace ftp://cda.harvard.edu/pub from the old test link with https://cxc.cfa.harvard.edu/cdaftp, and your link should work. It is important that you do not replace any of the other stuff in the link. The part of the link that looks like /ao__/cat_/____/primary/ still contains important parts of the link, as it navigates the subfolders in the archive to find your image.

Please Note: This method only works for links from past tests. If you want to get a new image from the archive that you do not have a link for, you will have to use the method below.

The Long Method: For Links From the UnOfficial Chandra Archive
If you want to actually retrieve an image from the archive to analyze that you do not already have a link to, you will need to navigate through the new archive to find it, using the link from the old archive.

1. First, you will need to find an image you want to look at. Search through the UnOfficial Chandra Archive like you normally would, until you have determined an image that looks appealing. You will not actually be able to follow the link, however, like you would have in the past to look at the files that this image contains.
2. Once you have found a satisfactory image, you will need to record some of the aspects of the link to it. First, you need to know the link that the Archive has for the image. This can be done by hovering your mouse over the Observation ID of the image and looking in the bottom left corner of your browser to see where the link leads, or copying and pasting the location of the link somewhere where you can view the link.
3. Looking at the link, you will see it looks something like ftp://cda.harvard.edu/pub/science/ao02/cat5/2000/primary/ (Note: This is just an example link, yours will look a little different). The important aspects of the link that you need to write down are:
   1. The number that comes after "ao" in the underlined part of the link. From now on, this will be referenced as the ao number.
   2. The number that comes after "cat" in the italicized part of the link. From now on, this will be referenced as the category.
   3. The number in the bolded part of the link. From now on, this will be referenced as the ObsID (because it is the Observation ID, you might notice).
4. Now, we look through the new archive. Go to https://cxc.cfa.harvard.edu/cdaftp/science/. You will see a list of ao numbers. Click on your ao number.
5. Now, you will see a list of categories. Click on your category.
6. Now, you will see a list of ObsIDs. Click on the ObsID of your image.
7. Now, you will see a list of files and folders. Click on "primary".
8. Finally, you will see a list of FITS files. Copy the *_evt2.fits file (or whichever one you want, evt2 is the most useful) and paste it into your JS9 "open remote" window. And that's it! You should be ready to go!

Another Final Note
The image link from the Nationals test last year (the 2020 nationals test) is fully broken. The file is no longer on soinc.org. Thus, you can either take the observation ID and follow the method above to search the archive for it, or you can just use this link: https://cxc.cfa.harvard.edu/cdaftp/scie ... t2.fits.gz.

Happy JS9ing!

Edit: The Chandra Archive works again. However, old test links still do not.

[honorstoise]

Thanks a lot, I thought my adblock was going insane or something lol.

[AstroClarinet]

The UnOfficial Chandra Archive works again!!!
However, as of 11/1/2020, it will no longer be updated, and new data will not be added.

Edit: Old links from the old archive should still be broken.