An initiative formed by astronomers and volunteer citizens has identified almost 100 possible brown rings in regions close to the Sun. These stars have a mass greater than that of large gas planets, but they are not massive enough to characterize stars.
The research is part of the Backyard Worlds: Planet 9 project, which is funded by NASA and has more than 100 thousand collaborators dedicated to the analysis of astronomical images. According to the study, a total of 95 candidates for brown rings were mapped, part of which are among the rings with the lowest temperatures already identified. According to scientists, the temperatures of some of the special objects are similar to those of Earth.
The brown rings can be 13 to 80 times more massive than Jpiter, however, they are not large enough to provide nuclear hydrogen fusion. This is the process that guarantees the characteristic brightness of stars. Since these space objects do not emit light like stars, scientists must use special instruments to study them, such as the WISE infrared space telescope, administered by NASA.
Citizens of the Backyard World project are trained to analyze images from WISE and other telescopes to capture signals from brown rings. The new study also counted on the help of the NIRES spectrometer, present at the Keck Observatory, in Hawaii, and the newly retired Spitzer infrared telescope.
Comparison of the size of other space bodies with the brown magnet. From right to left, the image represents the Earth, Jpiter, An Brown, a “low mass” star and the Sun. Image: NASA / JPL-Caltech / UCB
“We use NIRES to measure the temperature and gases present in its atmospheres. Each spectrum corresponds to a digital print that allows us to distinguish a cold brown magnet from other types of stars”, explains Adam Burgasser, co-author of the study and professor of physics at University of San Diego, in the United States, in a note.
Lead study author Aaron Meisner points out that the findings offer an opportunity to study the formation and atmosphere of planets beyond the Solar System. According to him, the new set of brown rings identified “allows to accurately estimate the number of floating worlds that roam the interstellar space near the Sun”, says the scientist.
According to the researchers, Backyard Worlds volunteers have already discovered more than 1,500 stars and brown rings in regions close to the Sun. The discovery, however, sets a record in the number of space objects identified in the same study of the project, says Meisner.
“Although new candidates for the brown rings in this work already demonstrate the power of citizen science to map the solar neighborhood, these objects represent only a small fraction of Backyard Worlds mobile object discoveries so far,” concludes the study.
Already available in pre-publication on the ArXiv repository, the research will be published in the Astrophysical Journal on Thursday (20).