HRdiagrammit

HRdiagrammit is a conceptual tool in astronomy education and research designed to facilitate work with Hertzsprung-Russell (HR) diagrams. The name combines the HR diagram with a German usage of mit meaning with, signaling an integrated approach to exploring stellar properties.

Overview

HRdiagrammit provides an interactive plotting environment for constructing HR diagrams from stellar catalogs. It supports common data sources such as Gaia, Hipparcos, and SDSS, and also user-uploaded datasets. Users can plot luminosity or absolute magnitude against effective temperature or color index, switch axes, and apply distance and extinction corrections. The interface offers isochrone overlays from theoretical models, evolutionary tracks, and tagging of stars by spectral type or variability.

Features

Key features include data import and cleaning, flexible axis configuration, interactive zooming and tooltips, isochrone and track overlays, filtering by color, magnitude, parallax, or quality flags, annotations and groupings, export of figures and data, and basic scripting capabilities to support reproducibility.

Applications

The tool is used in undergraduate teaching to demonstrate stellar evolution, in research data exploration, and in outreach materials to visualize class data or simulated stellar populations.

Limitations

HRdiagrammit relies on the quality of photometric and parallax data; results depend on adopted distance moduli, extinction corrections, and model isochrones. Users should be aware of biases in catalogs and limitations of simple conversions between observables and intrinsic properties.

See also

Hertzsprung-Russell diagram, Stellar evolution, Isochrones, Data visualization.