# Astrophysicists find green, pink and red surfaces among 151 white dwarfs within 65 light-years

- Published: 2026-11-05 00:06 UTC
- Section: Sky & Space › Astronomy
- Tags: white dwarfs, white dwarf colours, green white dwarf, pink white dwarf, WDJ1330+6435, WDJ0902+2010, synthetic photometry, CIE 1931 XYZ, stellar spectra, Mark Hollands
- URL: https://realtech.media/news/rt-f4566d19d947eb48d5cad4bf_astrophysicists_find_green/

**A British-German team used the spectra of 151 white dwarfs to model how the human eye would see them. Most are white; a few show green, pink or red surfaces.**

![Astrophysicists find green, pink and red surfaces among 151 white dwarfs within 65 light-years](https://sgzwpqqelzmajkcubgkl.supabase.co/storage/v1/object/public/rt-media/2026/11/d40083da29c1ae68.jpg)
*Sciences et Avenir*

A British-German team has determined the colours of 151 white dwarfs located 65 light-years away, Sciences et Avenir reports. Most of the stars are white, but a few show green, pink or red surfaces [1]. The lead author of the study is Mark Hollands, an astrophysicist at the University of Warwick (UK) [1].

White dwarfs are the remnants of low-mass stars similar to the Sun. They are only a few kilometres across, but extremely dense [1].

## From spectra to perceived colour

The researchers combined a set of white dwarf spectra. A spectrum shows the wavelengths at which photons are absorbed by certain molecules. They then fed the spectra into CIE 1931 XYZ, a model based on human vision, to obtain the true colour of each white dwarf [1].

This approach is the same as synthetic photometry. Astronomers use that technique to quantify the light a telescope receives for a given spectrum through several colour filters [1].

According to Hollands, the technique is the same as the one used to calibrate cameras, computer monitors and televisions, so that the colours of digital photos and video match what we perceive in real life as closely as possible. He added that starting from observed spectra makes the result as accurate as possible, and more accurate than simply attaching an RGB camera to a powerful telescope [1].

## Why some dwarfs are pink or green

The colour of a white dwarf depends on the main chemical element in the outermost layer of its atmosphere, and on other chemical compounds that absorb its light. Interaction between molecules can shift the absorption lines in the star's spectrum, which widens the range of colours [1].

On the pink dwarf WDJ0902+2010, dicarbon molecules at the surface absorb the yellow, blue and green wavelengths [1]. WDJ1330+6435 is the first white dwarf seen to be green. It is heated to about 4,000 degrees. Sodium there absorbs yellow, orange and red wavelengths. Calcium absorbs violet, and the energy is re-emitted into less absorbed parts of the spectrum, such as blue and green. Hollands says the star would appear pale green to the human eye [1].

Most of the 151 white dwarfs remain white. Their median temperature is 6,800 degrees, meaning half are hotter and half are colder. From this the study infers that one white dwarf in thirty in the Universe should show an unusual tint [1].

Hollands said that determining the colour of white dwarfs helps improve understanding of the physics of these stars, in particular of their outer atmospheric layer [1].

## Sources

1. [Sciences et Avenir](https://www.sciencesetavenir.fr/espace/voie-lactee/les-naines-blanches-pas-si-blanches-que-cela_195631)

---

Source: RealTech, realtech.media — https://realtech.media/news/rt-f4566d19d947eb48d5cad4bf_astrophysicists_find_green/