Photometry (concept)

Photometry is the quantitative measure of brightness of an object in an astronomical images.

Most coherent, developed, tested materials

• Movie (10:50) on Photometry, part of the "Filters, Magnitudes, Colors, Oh My!" playlist -- Dr. Luisa Rebull, 2020
• Movie (3:01) on Detections and Limits, part of the "Filters, Magnitudes, Colors, Oh My!" playlist -- Dr. Luisa Rebull, 2020
• Photometry overview -- Dr. Luisa Rebull (2010?)

Somewhat less coherent (or less standalone) materials

Aperture Photometry Overview -- Dr. Luisa Rebull (2010?)

PSF photometry - To come. Basic steps are essentially the same (detect objects, center up, determine what is background/source, sum up light for the source, check your results). More complicated than aperture photometry because you have many more free parameters than for aperture photometry.

• (this is cross-posted in 'concept' and 'skill' for Photometry) In 2019, an alumni team (Olivia Kuper and Tom Rutherford) were trying to carry our original photometry on Herschel images further. We had sources clumped close together on the sky, and even though aperture photometry was ok for our original project, they were trying to learn how to do PSF photometry in Python. They were struggling with vast array of free parameters. I wrote this Photometry Scaffolding document in an effort to help them understand, in words, what the free parameters were and why they mattered. This may or may not be useful for anyone else, but as I put a lot of time into it, I thought I'd post it here. -- Dr. Luisa Rebull, 2019

Other sources of interest

• Your local astronomy textbook or (if neccessary) the Wikipedia entry for photometry is probably a good place to go for a longer general introduction.
• The IRAF manuals are old but still very, very valid. If you can pay attention to the concepts and ignore the IRAF-specific instructions, you can learn an awful lot from these manuals. Oldies but goodies.
• https://www.aavso.org/
• http://gtn.sonoma.edu/members/basic.php
• http://lcogt.net/en/book/introduction-photometry
• http://www.minorplanet.info/ObsGuides/Misc/photometryguide.htm