NASA’s SPHEREx space telescope has identified traces of water, methane and carbon compounds in the atmospheres of 37 nearby brown dwarfs. The research, announced by the institution on October 8, examines the chemical diversity of these celestial bodies between stars and giant planets. However, the measurements cover a fairly wide temperature range, from approximately 2200 degrees to minus 20 degrees.
In the new SPHEREx study, researchers separated the chemical signatures of atmospheres by comparing the brightness of light in 102 different colors. Accordingly, observations show the effects of water and methane, as well as carbon dioxide and carbon monoxide molecules, on light. On the other hand, even brown dwarfs at the same temperature can present different spectra, challenging existing models.
Brown dwarfs are formed by the collapse of gas clouds like stars, but they cannot reach the mass to sustain continuous hydrogen fusion in their cores. In addition, the research examines the phase in which the clouds of these objects thin as they cool and pass into methane-rich atmospheres. Following the first detailed sample, the team continues to analyze data from thousands of other brown dwarfs and expands the sample. In addition, NASA states in its new statement that SPHEREx data is provided free of charge to scientists and the public.
102 color measurements reveal chemical differences that a single photograph does not show
SPHEREx’s measurement method separates light into wavelengths, unlike an image that only shows the shape of a celestial body. According to JPL’s mission statement, molecules give away their chemical composition by leaving distinctive signatures in the colors they absorb or emit. Therefore, researchers can identify compounds using these traces carried by light without taking physical samples from a distant atmosphere.
In addition, spectral measurements help calculate the distances of distant galaxies and map their positions in the universe in three dimensions. While SPHEREx scans the entire sky, telescopes such as Webb and Hubble obtain more detailed images of selected targets. Therefore, wide-area scanning serves to compare the surroundings of individual targets and the common features of similar objects.
On the other hand, the mission also investigates water in the Milky Way and the distribution of other compounds essential for life in ice. These ices are found in interstellar clouds and make visible to researchers the chemical material that could participate in the formation of new stars and planets. However, these chemical traces do not constitute a direct result indicating that there is life on a celestial body.
Additionally, the telescope’s broad sweep looks for trends between different galaxies and groups of stars that are not seen in detailed observations alone. Thus, the new brown dwarf study also shows how the same measuring tool can be used to study atmospheric chemistry. The focus of the research is to understand the relationship between the temperature of these dark objects and the molecules in their atmosphere through observational data.