README.md

In cowboy2718/Hertzsprung-Russell: Hertzsprung-Russell Diagram with R

Hertzsprung-Russell

R package to explore stellar evolution based on the Hertzsprung-Russell diagram

Exploring Space and Time | University of Arizona | Fall 2018

Created by Tony Gojanovic

Background

This package provides tools for visual exploration of stellar data using the Hertzsprung-Russell diagram using two types of data sets and two Hertzsprung-Russell graph interpretations (observation and theoretial H-R diagrams).

What is the Hertzsprung-Russell diagram

The Hertzsprung-Russell diagram, or H-R diagram, is a powerful tool classifying stars in order to understand the nature of stellar evolution. More specifically, from Wikipedia, we have "The Hertzsprung–Russell diagram, abbreviated H–R diagram, HR diagram or HRD, is a scatter plot of stars showing the relationship between the stars' absolute magnitudes or luminosities versus their stellar classifications or effective temperatures. More simply, it plots each star on a graph measuring the star's brightness against its temperature (color). The related colour–magnitude diagram (CMD) plots the apparent magnitudes of stars against their colour, usually for a cluster so that the stars are all at the same distance. The diagram was created circa 1910 by Ejnar Hertzsprung and Henry Norris Russell and represents a major step towards an understanding of stellar evolution."

For more information, see references below.

Observational H-R Diagram

The following diagram is an example of an observational H-R diagram based on the Yale Trigonometric Parallax Dataset (n=6220 data points). The plot shows stars by absolute magnitude and color type. The graph produced by the R package is not interactive. Note that the graph colors are not an exact match to star color, but rather just show delineations of different regions.

Theoretical H-R Diagram

The following diagram is an example of a theoretical H-R diagram based on the McDonald Observatory data (n = 57 data points). The plot shows stars by absolute magnitude and degrees Kelvin. The example is not interactive, but the graphic produced by the R package is designed to be interactive which can be used for visual learning projects.

The interactive plot also provides a tooltip that can be used to hover over individual stars to show additional information such as apparent magnitude, spectral type, constellation, right ascension and declination. A selection of "hypervelocity" stars have also been included in this graph.

Note that the graph colors are not an exact match to star color, but rather just show delineations of different regions.

The exercises that accompanies this data may be found at https://mcdonaldobservatory.org/sites/default/files/pdfs/teachers/hrd.pdf

Interactive HTML File (Visual Learning Projects)

For the complete interactive HTML file, which can be used for a visual learning project, contact the author at [e-mail]

Package Details

Specific details on the package HRDiagram may be obtained through the vignette files. The vignette files show specific usage and syntax.

To see the vignette file click here http://htmlpreview.github.io/?https://github.com/cowboy2718/Hertzsprung-Russell/blob/master/vignettes/HR_Diagram.html

Package Name and Location

To install this R package and begin exploring stellar life, use devtools and the following:

devtools::install_github('cowboy2718/HRDiagram')
library(HRDiagram)

Travis Badge

The following indicates the status of the most recent build with Travis:

References

The following are useful resources.

Audouze and Guy Israel, editors, The Cambridge Atlas of Astronomy, Third Edition, Cambridge University Press, 1996.

Croswell, Ken, "Hypervelocity Stars," Sky & Telescope, December 2018, pp. 30 - 33.

Hemenway, Mary Kay and Brad Armosky, "H-R Diagram," The University of Texas at Austin McDonald Observatory, 2001. Website: https://mcdonaldobservatory.org/sites/default/files/pdfs/teachers/hrd.pdf

North, Gerald, Astronomy Explained, Springer, London, 1998.

More info on H-R Diagrams from Wikipedia

cowboy2718/Hertzsprung-Russell documentation built on May 23, 2019, 1:46 p.m.