FITS Tutorial Exercise

[payneck]

Exercise 2 with the Horsehead Nebula "Show the image of the Horsehead Nebula, but in units of surface brightness (magnitudes per square arcsecond). (Hint: the physical size of the image is 15x15 arcminutes.)" http://learn.astropy.org/FITS-images.html Not sure how to set tis up, no solutions available. Any help would be appreciated!

[kakirastern]

Yeah, a lot has been assumed in that tutorial. I will open a PR to follow up on it and add content to that notebook to clarify the assumptions made.

[payneck]

Thank you! I like the tutorials, as do my students, but this one exercise was a bit of a struggle.

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On Wed, May 13, 2020 at 12:57 PM Kris Stern ***@***.***> wrote: Yeah, a lot has been assumed in that tutorial. I will open a PR to follow up on it and add content to that notebook to clarify the assumptions made. — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#450 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AEZY4GJYWB4O24BZR52KWFLRRLGPPANCNFSM4M75XH4Q> .

-- Charlie Payne, MEd Instructor of Physics, Computational Physics DEEP (Online) and Residential Head Cross Country Coach USATF Level II Coach: Endurance Specialty USATF Level I Coach, Track and Field *NORTH CAROLINA SCHOOL OF SCIENCE AND MATHEMATICS* 1219 Broad Street | Durham, NC 27705-3577 | 123.456.7890 *Igniting innovation, cultivating community.* |* NCSSM.EDU <http://ncssm.edu/>*

[kakirastern]

You are welcome!

[kakirastern]

Will try to get this done within the next couple of weeks

[payneck]

Thank you so much. I actually talked about this resource yesterday to our Astronomy teacher, and I'd like to use it in the courses I teach, including Comp Phys. There is no hurry, and I'm really looking forward to the results. Again, thank you. Stay healthy. Charlie

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On Wed, Aug 12, 2020 at 11:30 AM Kris Stern ***@***.***> wrote: Will try to get this done within the next couple of weeks — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#450 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AEZY4GKTBCTS32DN2E7RDV3SAKYQXANCNFSM4M75XH4Q> .

-- Charlie Payne, MEd Instructor of Physics, Computational Physics DEEP (Online) and Residential Head Cross Country Coach USATF Level II Coach: Endurance Specialty USATF Level I Coach, Track and Field *NORTH CAROLINA SCHOOL OF SCIENCE AND MATHEMATICS* 1219 Broad Street | Durham, NC 27705-3577 | 919-416-2765 *Igniting innovation, cultivating community.* |* NCSSM.EDU <http://ncssm.edu/>*

[kakirastern]

Hi @payneck thanks for the reply! You are welcome. I will let you know once the proposed PR is approved and merged.

[kakirastern]

@mwcraig As discussed during telecon today, please have a look at the issue and let us know if any revisions need to be made on the FITS-images tutorial. Looks like the actual calculation involves more than just an inverse-square relationship, at least at the senior undergraduate level.

[mwcraig]

I have a few comments about the tutorial (which I suppose I should turn in to a pull request):

1. The level is good for the most part.
2. It would be helpful to link more to other resources. For example, the image sum done in the tutorial is fine but a link to ccdproc for other image combination methods would be good.
3. The tutorial should probably have users also read in the header, not just the data.
4. Perhaps consider reading in the image using CCDData instead of io.fits, or use the context manager with fits.open....
5. That last exercise is a doozy.
   • It is unclear to me what is intended: are counts supposed to be converted to the standard magnitude system first? If so, what units is the image in?
   • Doing the conversion requires a bunch of astro knowledge that is out of scope for this notebook, potentially including how to go from flux to magnitudes, calculating pixel size, etc.
   • I would replace the example with something different...or add much more detail about how to go from whatever the units are for the original image to surface brightness.

[kakirastern]

Thanks @mwcraig for the comments! Let me open a PR and make some preliminary changes according to your suggestions so that it will be easier for you to follow up.

[kakirastern]

Just opened this Google Colab for the drafting part of the PR workflow: https://colab.research.google.com/drive/1rk9dig_LFw_XArLe0KJSFi8lOTKE5QPH?usp=sharing

Editing or commenting is currently by invitation only, but everyone with the link can view it

[kakirastern]

Checklist of things TODO in the Colab notebook:

• Link to more resources: Add a link for the image sum done in the tutorial to ccdproc for details regarding image combination methods.
• Have the user to also read in the header, not just the data.
• To have the image read in either using CCDData or use the context manager with fits.open() instead of io.fits. (Remark: Tried it but do not think it would work so well, better stick with original.)
• Rework exercise to provide the formula(e) to be used for the unit conversion as well as some hint(s) where applicable.

[kakirastern]

@mwcraig Google Colab notebook ready for a review.