The Sonified Hertzsprung-Russell Diagram

Abstract

Understanding the physical properties of stars, and putting these properties into the context of stellar evolution, is a core challenge in astronomical research. A key visualization in studying stellar evolution is the Hertzsprung-Russell diagram (HRD), organizing data about stellar luminosity and colour into a form that is informative about stellar structure and evolution. However, connecting the HRD with other sources of information, including stellar time series, is an outstanding challenge. Here we present a new method to turn stellar time series into sound. This method encodes physically meaningful features such that auditory comparisons between sonifications of different stars preserve astrophysical differences between them. We present an interactive multimedia version of the HRD that combines both visual and auditory components and that allows exploration of different types of stars both on and off the main sequence through both visual and auditory media.

Open Your Ears and Take a Look: A State‐of‐the‐Art Report on the Integration of Sonification and Visualization

“…Sonifigrapher [Rib19] is a virtual synthesizer that lets users sonify the light curves data from NASA's exoplanet archive. Also, the recently presented Sonified Hertzsprung‐Russel Diagram [HPDW23] sonifies the light curves, with the diagram acting as both the visualization and the interface to choose a star to be sonified. With this design, hearing a constant pitch will inform a user about the rotation of a star.…”

“…A multi‐scale audification method is presented where different speed factors are used depending on the size of each dataset, and different sound designs are used to highlight specific properties of the data. Huppenkothen et al [HPDW23] created an audiovisual version of the Hertzsprung‐Russell Diagram where the user can listen and compare auditory representations of each type of star that is included in the diagram (see Figure 7(c)). It is also possible to filter the diagram according to certain criteria, which, in turn, filters which sonifications can be listened to.…”

“…Discussion : From the data, we see that parameter mapping is by far the most used sonification technique for the design of audiovisual idioms − 53 out of 57 papers in the database employ some sort of parameter mapping sonification. Only seven of them combine parameter mapping sonification with other techniques such as audification [MMU16,HPDW23], earcons [HAR16,NSC16], or auditory icons [BBV16, RFK*15, PBM15]. The technique of audification is part of the database three times on its own [PFH*22, HCTP14,WW15], and once in combination with earcons in a second design of a paper [PFH*22].…”

“…(b) An immersive virtual environment for audiovisual spatialized data sonification presented by Chabot and Braasch [CB17]. (c) A screenshot showing the interactive interface for the sonified Hertzsprung‐Russel diagram by Huppenkothen et al [HPDW23]. All screenshots CC BY 4.0.…”

“…Other forms of interaction include simpler tasks such as browsing sonifications of individual or groups of data objects [Rib19, LSB*23]. Huppenkothen et al [HPDW23] created an interactive multimedia version of the Hertzsprung‐Russell Diagram, where a user can select individual data entries of the diagram to listen to their sonification. On the other hand, there also exist more complex forms of interactions such as navigating a 3D environment [BB19, JMP13,MNW*18].…”