Help on photometric Plots
The photometric plot facility allows to produce three different kinds of diagrams:
- Colour-magnitude and colour-colour diagrams for one photometric system, using data from one data source,
- Colour-magnitude and colour-colour diagrams for two photometric systems, using data from two data sources, one for each system,
- Scatter plots comparing the values of one parameter taken from one or two photometric systems.
The plots are active, so that stars can be identified by clicking on the points.
Because the plot are made on the basis on the original data file, one needs to
select the data sources.
To help on such decision, the number of stars in each data source is
indicated within brackets and a link is provided to get the full text of the reference. Only the data sources with more than 5 stars are listed.
1) Diagrams for one photometric system
These diagrams are the colour-magnitude and colour-colour diagrams.
To obtain such plots:
- Select one photometric system,
- Select two parameters,
- Select a data source,
- Click on the button "Plot".
2) Diagrams for two photometric systems
These diagrams are the colour-magnitude and colour-colour diagrams.
To obtain such plots:
- Select two photometric systems,
- Select one parameter for each system,
- Select the corresponding data sources,
- Click on the button "Plot".
3) Difference diagrams for one or two photometries
The ploting facility offers also the possibility to compare the available data,
as, for example, the V magnitude for two different data sources with one system,
or between two systems.
If you want to compare the V magnitudes for two data sources in
the UBV system:
- Select the photometric system (UBV),
- Select the parameter (V),
- Select two data sources.
- Click on the button "Plot".
If you want to compare the V magnitudes for two data sources, one from UBV and one from uvby:
- Select the photometric systems (UBV and uvby),
- Select the parameter in both systems (V),
- Select the corresponding data sources.
- Click on the button "Plot".
Last update: 09 December 2005