A 16 hr Transit of Kepler-167 e Observed by the Ground-based Unistellar Telescope Network

• Published in: Astrophysical journal. Letters Vol. 940; no. 2; p. L39
• Main Authors: Perrocheau, Amaury, Esposito, Thomas M., Dalba, Paul A., Marchis, Franck, Avsar, Arin M., Carrera, Ero, Douezy, Michel, Fukui, Keiichi, Gamurot, Ryan, Goto, Tateki, Guillet, Bruno, Kuossari, Petri, Laugier, Jean-Marie, Lewin, Pablo, Loose, Margaret A., Manganese, Laurent, Mirwald, Benjamin, Mountz, Hubert, Mountz, Marti, Ostrem, Cory, Parker, Bruce, Picard, Patrick, Primm, Michael, Randolph, Justus, Runge, Jay, Savonnet, Robert, Sharon, Chelsea E., Shih, Jenny, Shimizu, Masao, Silvis, George, Simard, Georges, Simpson, Alan, Sivayogan, Thusheeta, Stein, Meyer, Trudel, Denis, Tsuchiyama, Hiroaki, Wagner, Kevin, Will, Stefan
• Format: Journal Article
• Language: English
• Published: Austin The American Astronomical Society 01.12.2022; IOP Publishing
• Subjects: Amateur astronomers; Astronomy data analysis; Astronomy data modeling; Astronomy education; Celestial bodies; Exoplanet detection methods; Exoplanets; Extrasolar planets; Ground-based observation; Jupiter; Light curves; Observational astronomy; Observatories; Optical telescopes; Planetary orbits; Space telescopes; Telescopes; Transit; Transit photometry; Transits; Universal time
• ISSN: 2041-8205; 2041-8213
• DOI: 10.3847/2041-8213/aca073

Abstract More than 5000 exoplanets have been confirmed and among them almost 4000 were discovered by the transit method. However, few transiting exoplanets have an orbital period greater than 100 days. Here we report a transit detection of Kepler-167 e, a “Jupiter analog” exoplanet orbiting a K4 star with a period of 1071 days, using the Unistellar ground-based telescope network. From 2021 November 18 to 20, citizen astronomers located in nine different countries gathered 43 observations, covering the 16 hr long transit. Using a nested sampling approach to combine and fit the observations, we detected the midtransit time to be UTC 2021 November 19 17:20:51 with a 1 σ uncertainty of 9.8 minutes, making it the longest-period planet to ever have its transit detected from the ground. This is the fourth transit detection of Kepler-167 e, but the first made from the ground. This timing measurement refines the orbit and keeps the ephemeris up to date without requiring space telescopes. Observations like this demonstrate the capabilities of coordinated networks of small telescopes to identify and characterize planets with long orbital periods.