Global Citizen Scientists Confirm Discovery of Rare Gas Giant Exoplanet

Albuquerque, NM (SPX) — A groundbreaking collaboration among astronomers, led by the University of New Mexico (UNM), has successfully confirmed the existence of a rare gas giant exoplanet named TOI-4465 b, situated approximately 400 light-years from Earth. This significant discovery, detailed in a recent publication in *The Astronomical Journal*, was made possible through the efforts of a global network of citizen scientists and professional observatories.

The identification of TOI-4465 b was initiated by NASA's Transiting Exoplanet Survey Satellite (TESS), which detected the exoplanet during a single-transit event. Confirming its existence posed a considerable challenge due to its 102-day orbital period, necessitating long, uninterrupted observation windows. "Each transit lasts about 12 hours, but it is incredibly rare to get 12 full hours of dark, clear skies in one location," explained Zahra Essack, a postdoctoral fellow at UNM and the lead author of the study.

The complexity of confirming TOI-4465 b's existence was compounded by weather conditions, telescope availability, and the need for continuous observation. To overcome these hurdles, the research team coordinated an international campaign involving 24 citizen scientists from 10 countries. These participants utilized personal telescopes to provide time-critical photometric data, capturing brightness dips as the planet transited in front of its star.

The participation of citizen scientists in this endeavor underscores the integral role that astronomy enthusiasts play in advancing scientific research. "The discovery and confirmation of TOI-4465 b illustrate how passionate individuals can contribute directly to frontier scientific inquiries," Essack stated.

The research effort was supported by various organizations, including the TESS Follow-up Observing Program Sub Group 1 (TFOP SG1), the Unistellar Citizen Science Network, and the TESS Single Transit Planet Candidate (TSTPC) Working Group, led by Assistant Professor Diana Dragomir at UNM. These platforms provided standardized tools, coordination frameworks, and expertise necessary for the collection and analysis of high-quality data.

TOI-4465 b is approximately 25% larger in radius than Jupiter, nearly six times more massive, and possesses a density nearly three times that of Jupiter. Its mildly elliptical orbit results in surface temperatures ranging from 375 to 478 K (200-400 °F), positioning it within a temperate regime that remains underrepresented in current exoplanetary populations. Essack emphasized, "Studying these long-period planets offers insights into how planetary systems form and evolve under more moderate conditions."

The discovery is particularly significant due to the scarcity of long-period exoplanets—those with orbital periods exceeding 100 days—stemming from observational limitations. The unique characteristics of TOI-4465 b make it an ideal candidate for future atmospheric studies using advanced instruments such as the James Webb Space Telescope (JWST), especially via emission spectroscopy.

The implications of this discovery extend beyond mere academic interest; they may influence our understanding of planetary formation and evolution in the universe. As research in this field advances, TOI-4465 b could provide vital data that enriches our knowledge of gas giants and their atmospheres, paving the way for further explorations of distant worlds.

In summary, the confirmation of TOI-4465 b not only highlights the collaborative efforts of citizen scientists and astronomers but also emphasizes the importance of continued exploration and research in the realm of exoplanet studies. As the field evolves, future discoveries may illuminate the complexities of planetary systems beyond our own, contributing to a broader understanding of the cosmos.