(creating the page) |
(aperture) |
||
| Line 1: | Line 1: | ||
'''PAGE BEING WRITTEN''' | '''PAGE BEING WRITTEN''' | ||
Siril is capable of analysing star photometry across a sequence to do a [https://en.wikipedia.org/wiki/Light_curve light curve]. See [https://siril.org/tutorials/photometry/ this tutorial] for more information on how to proceed. This page is more a technical documentation. | Siril is capable of analysing star photometry across a sequence to do a [https://en.wikipedia.org/wiki/Light_curve light curve], using [http://spiff.rit.edu/classes/phys445/lectures/photom/photom.html aperture photometry]. See [https://siril.org/tutorials/photometry/ this tutorial] for more information on how to proceed. This page is more a technical documentation. | ||
[[File:Siril_Magnitude.png|700px]] | [[File:Siril_Magnitude.png|700px]] | ||
| Line 9: | Line 9: | ||
* '''inner and outer radius: ''' measuring the magnitude of an object involves measuring the flux of the object and the flux of the background. To sample the background, we must choose pixels that are far away from the object to not contain it, and close enough to be the same background and if possible not contain other objects. An [https://en.wikipedia.org/wiki/Annulus_(mathematics) annulus] is created with these inner and outer radii, in which background pixels will be sampled | * '''inner and outer radius: ''' measuring the magnitude of an object involves measuring the flux of the object and the flux of the background. To sample the background, we must choose pixels that are far away from the object to not contain it, and close enough to be the same background and if possible not contain other objects. An [https://en.wikipedia.org/wiki/Annulus_(mathematics) annulus] is created with these inner and outer radii, in which background pixels will be sampled | ||
* '''aperture: ''' | * '''fixed or dynamic aperture: ''' aperture is the radius around the star centroid where we consider pixels to be part of the star and contribute to its flux. It must be small enough to contain other stars and too much background and large enough to contain all the pixels modified by the star. We have a setting <tt>force aperture</tt> that allows the aperture to be specified with a constant (not enabled by default). When not enabled, the aperture is set to two times the FWHM, for each star. | ||
* '''gain: ''' | * '''gain: ''' | ||
* '''min and max pixel values: ''' | * '''min and max pixel values: ''' | ||
Revision as of 20:36, 9 May 2022
PAGE BEING WRITTEN
Siril is capable of analysing star photometry across a sequence to do a light curve, using aperture photometry. See this tutorial for more information on how to proceed. This page is more a technical documentation.
There are a few parameters that drive this, available from preferences.
- inner and outer radius: measuring the magnitude of an object involves measuring the flux of the object and the flux of the background. To sample the background, we must choose pixels that are far away from the object to not contain it, and close enough to be the same background and if possible not contain other objects. An annulus is created with these inner and outer radii, in which background pixels will be sampled
- fixed or dynamic aperture: aperture is the radius around the star centroid where we consider pixels to be part of the star and contribute to its flux. It must be small enough to contain other stars and too much background and large enough to contain all the pixels modified by the star. We have a setting force aperture that allows the aperture to be specified with a constant (not enabled by default). When not enabled, the aperture is set to two times the FWHM, for each star.
- gain:
- min and max pixel values: