Thanks for making these videos. I am currently seeking a BS in Astrophysics, and I am on a research team and everything you have covered has been monumentally useful for me getting accustom to Jupyter Notebook and coding in general. Looking forward to what you release next! Good luck with school, mate!
Thank you so much for your work! It really helped me a lot :) You said that there'll be no videos for a while because of getting back to school, why don't you start a text-based blog, to upload when you're bit busy, which'll be a lot easier to make tutorials than on RUclips Videos?
Yes you can! However, if the Galaxy in question is blocked by stars in our own galaxy, you should subtract the aperture sum of the blocking stars to produce an accurate measurement of the magnitude of that Galaxy.
Yes, I apologize for not mentioning this in the video, but acstools can only search HST catalogues. I don’t know of a program for searching CTIO, so you may need to search the CTIO catalogues yourself to find the zero point of your image.
Creating a CMD or HR diagram would require us to find the color index of the stars, which means we would need two fits images of the same piece of sky: one taken with a B (blue) filter, and one with a V (green) filter. The color index of each star would then be its magnitude in the B filter image minus its magnitude in the V filter image. Once you find the color index of each star, you can estimate its temperature and luminosity, then creating a CMD and HR diagram should be fairly straightforward from there using Matplotlib. If I can get my hands on B and V filtered fits images, I would love to make a video on this.
@@mic_n_ike https(://)mast(.)stsci(.)edu(/)portal(/)Mashup(/)Clients(/)Mast(/)Portal(.)html You might find them here, if that's what you meant by "if I can get my hands on". I'd love you to watch your videos on this if you continue from where you left off.
@@mic_n_ike another question. I've been also trying to do isochrone fitting but the fact that you have to basically eyeball it when it comes to finding the perfect isochrone fit for your HR diagram makes me uncomfortable. It seems like this method leaves a lot of room for error. So could you suggest another method which may be more accurate or is isochrone fitting good enough?
@@luce1F the isochrones package for Python has some tools that you might find useful. Here’s a link to the docs isochrones.readthedocs.io/en/latest/#:~:text=Isochrones%20is%20a%20python%20package%20that%20provides%20a,single-%20or%20multiple-star%20systems%2C%20based%20on%20arbitrary%20observables.
I apologize for not mentioning this in the video, but acstools can only be used to search the HST catalogues. If you want to find the zero point for other space telescope data, you will need to search through the documentation for that telescope yourself.
Hello blogger, this video is very useful for me. I am learning the observation and data processing of variable stars. There is a problem that puzzles me, how to draw the light curve of a star with a fit file?
No, they are not, because we are measuring the magnitude of these stars as observed from space (i.e. as measured by the Hubble Space Telescope). Airmass corrections typically need to be made due to distortions from Earth’s atmosphere, but we don’t need to consider making such corrections when in space.
@@graphenoid my apologies, I mostly work with HST, and forgot to consider ground-based telescopes. However, hopefully by following my tutorial, you are able to modify the code to suit your needs. If you need help with the programming please let me know. :)
Very thank you for your explanations. That's huge great to me.
Thanks for making these videos. I am currently seeking a BS in Astrophysics, and I am on a research team and everything you have covered has been monumentally useful for me getting accustom to Jupyter Notebook and coding in general. Looking forward to what you release next! Good luck with school, mate!
Glad I could help you out! Best of luck with your research 😁
Great video. Thanks Micah!
Thank you so much. It cleared things out for me. Cheers!
Thank you so much for your work! It really helped me a lot :) You said that there'll be no videos for a while because of getting back to school, why don't you start a text-based blog, to upload when you're bit busy, which'll be a lot easier to make tutorials than on RUclips Videos?
High. Thanks for the video. May i follow same steps to know the magnitude of a galaxy through fixed aperture??
Yes you can! However, if the Galaxy in question is blocked by stars in our own galaxy, you should subtract the aperture sum of the blocking stars to produce an accurate measurement of the magnitude of that Galaxy.
What if i have to calculate zp for a ctio observed image?? Acstools doesnt work there.
Thanks in advance.
Same question here
Yes, I apologize for not mentioning this in the video, but acstools can only search HST catalogues. I don’t know of a program for searching CTIO, so you may need to search the CTIO catalogues yourself to find the zero point of your image.
How do i create a CMD or an HR diagram from where this video leaves off? Would you be willing to make a video on that?
Creating a CMD or HR diagram would require us to find the color index of the stars, which means we would need two fits images of the same piece of sky: one taken with a B (blue) filter, and one with a V (green) filter. The color index of each star would then be its magnitude in the B filter image minus its magnitude in the V filter image. Once you find the color index of each star, you can estimate its temperature and luminosity, then creating a CMD and HR diagram should be fairly straightforward from there using Matplotlib. If I can get my hands on B and V filtered fits images, I would love to make a video on this.
@@mic_n_ike https(://)mast(.)stsci(.)edu(/)portal(/)Mashup(/)Clients(/)Mast(/)Portal(.)html
You might find them here, if that's what you meant by "if I can get my hands on". I'd love you to watch your videos on this if you continue from where you left off.
@@mic_n_ike another question. I've been also trying to do isochrone fitting but the fact that you have to basically eyeball it when it comes to finding the perfect isochrone fit for your HR diagram makes me uncomfortable. It seems like this method leaves a lot of room for error.
So could you suggest another method which may be more accurate or is isochrone fitting good enough?
@@mic_n_ike you can try the mikulski archives for the fits images. Lots of them there. Unfortunately RUclips thought my link was spam and deleted it.
@@luce1F the isochrones package for Python has some tools that you might find useful. Here’s a link to the docs isochrones.readthedocs.io/en/latest/#:~:text=Isochrones%20is%20a%20python%20package%20that%20provides%20a,single-%20or%20multiple-star%20systems%2C%20based%20on%20arbitrary%20observables.
What if my FIT image wasn't taken by the Hubble telescope, so it's not compatible with its filters?
I apologize for not mentioning this in the video, but acstools can only be used to search the HST catalogues. If you want to find the zero point for other space telescope data, you will need to search through the documentation for that telescope yourself.
@@mic_n_ike Ty
Hello blogger, this video is very useful for me. I am learning the observation and data processing of variable stars. There is a problem that puzzles me, how to draw the light curve of a star with a fit file?
You can use the Gammapy package to model light curves. Here's a link to a tutorial that might be helpful: docs.gammapy.org/0.9/notebooks
Thank you very much for you reply,which is very useful to me.@@mic_n_ike
but these magnitudes are not airmass corrected.
No, they are not, because we are measuring the magnitude of these stars as observed from space (i.e. as measured by the Hubble Space Telescope). Airmass corrections typically need to be made due to distortions from Earth’s atmosphere, but we don’t need to consider making such corrections when in space.
@@mic_n_ike Yes, I know, but it would be good if the video also explained the process for Earth-based telescopes as well.
@@graphenoid my apologies, I mostly work with HST, and forgot to consider ground-based telescopes. However, hopefully by following my tutorial, you are able to modify the code to suit your needs. If you need help with the programming please let me know. :)
@@mic_n_ike Thank you so much.