October 29, 2020 – Marseille, France and Mountain View, CA. There are nearly one million catalogued asteroids, but we do not know much about many of them. Now Unistellar and its scientific partner, the SETI Institute, can count on a network of nearly 3,000 amateurs capable of observing thousands of asteroids and providing an estimate of their size and shape. With mobile stations located in Asia, North America and Europe, the Unistellar network, the largest network of citizen astronomers, participates in cutting-edge research and has delivered its first scientific results including the 3D shape model of an asteroid and the size of another one.
Figure 1_Rachel Knight and Brad Davis, asteroid detectors from the Unistellar network
Figure 2_Bruce Parker, an asteroid detector from the Unistellar network
“The Unistellar eVscope is more than a telescope. It’s also a tool to access a network made of citizen astronomers throughout the world who can observe together and participate in scientific campaigns,” said Franck Marchis, senior planetary astronomer at the SETI Institute and Chief Scientific Officer at Unistellar. “Today more than 150 people have already contributed to our campaigns and collected valuable scientific data from their backyard.”
In addition to the SETI Institute, Marchis’ group collaborated with Josef Hanuš and Josef Ďurech of the Institute of Astronomy at Charles University to identify potential targets of interest in the asteroid population. “After having designed and validated our data analysis pipeline in 2020, we can now routinely propose campaigns to our citizen astronomers,” said Marchis.
Asteroid 943 Begonia: An Occultation Event
Although it was discovered in October of 1920, we do not know much about asteroid 943 Begonia’s size. Ines Demuys, Unistellar Engineer, identified an occultation event by Begonia. An occultation is when a star temporarily disappears when an asteroid (or something else) passes in front of it. Two U.S.-based citizen astronomers, based in Arizona and in New York, detected the occultation with their eVscopes (Unistellar’s digital telescopes) in September of 2020. Analysis of the data they collected revealed that the main-belt asteroid could have a diameter of 83 km, making it 20% larger than previously known.
Figure 3_Asteroid Begonia reshaped thanks to the Unistellar network
“The main difficulty of these kinds of observations is to be located in the right place and to observe at the right time,” said Marchis. “Timing, good weather and a little luck are necessary. Fifty-three occultations campaigns were launched, leading to 10 positive detections, but as the process matures in the coming weeks, positive detections will indeed happen more often. Combined with an increasing number of observers we thus expect a growing number of evermore accurate scientific results.”
Asteroid 787 Moskva: Lightcurve Inversion
Another way to study asteroids is to measure the variation of light reflected due to their irregular shape. “Despite its relatively small aperture size, the eVscope is powerful enough to characterize around ~6,000 known asteroids in a year. SETI Institute Research Assistant Joe Asencio selected the main-belt asteroid 787 Moskva, which has an estimated diameter of 30 km. We asked our network to observe it for more than one hour in August 2020, and 7 citizen astronomers from 4 different countries, USA, Finland, Switzerland, and France sent their observations,” said Tom Esposito, an astronomer at the SETI Institute and UC Berkeley.
Figure 4_New shape of asteroid Moskva
The flux variation over time, also called a lightcurve, showed the asteroid’s spin and confirmed a spin period of 6.056 hours. Combining these new observations with previous ones, the team at Charles University found a new shape model of the asteroid, which is quite elongated and has a diameter between 25-30 km.
“This observation validates the use of the eVscope for accurate photometric studies, including transiting exoplanets, variable stars, supernovae and other transient events, significantly increasing the number of investigations possible with the Unistellar network,” said Esposito.
New Research Topics
“Getting people excited about the night sky and allowing them to make important discoveries are at the core of Unistellar’s mission.” said Laurent Marfisi, Unistellar’s CEO. “We were thrilled to see these first discoveries by our community of users and cannot help but look forward to exploring new research topics. Possibilities could include Planetary Defense and Exoplanet Discovery, two areas where we already have had measurements from users.”
Figure 5_Citizen science menu in the Unistellar app
Science team members at the SETI Institute and Unistellar include Joé Asencio, Guillaume Blaclard, Inès Demuys, Christian Everett, Val Klavans, Dan Peluso, Thomas Esposito, and Franck Marchis. Citizen astronomers who participated in these campaigns include Richard Born, Brad Davis, Bruno Guillet, Rachel Knight, Julien de Lambilly, Matthieu Lauvernier, Bruce Parker, Sam Rihani, Petri Tikkanen.
Unistellar’s asteroid program, including selected occultation events, is accessible here: https://unistellaroptics.com/asteroid-program/
Proceedings paper published as an IAC proceedings available here.
About the SETI Institute
Founded in 1984, the SETI Institute is a non-profit, multi-disciplinary research and education organization whose mission is to explore, understand, and explain the origin and nature of life in the universe and the evolution of intelligence. Our research encompasses the physical and biological sciences and leverages expertise in data analytics, machine learning and advanced signal detection technologies. The SETI Institute is a distinguished research partner for industry, academia and government agencies, including NASA and NSF.
Unistellar is the start-up behind the eVscope, a uniquely fun and easy-to-use consumer telescope bringing the wonders of the Universe to life. Thanks to a partnership with the SETI Institute, this extremely powerful tool also allows its users to become citizen scientists and contribute to cutting-edge research on exoplanet transits, asteroid occultations, comets, and much more.
The Unistellar eVscope received a CES Innovation Award in 2018 in the category Tech for a Better World and has been nominated for a SXSW 2019 Innovation Award. 3,000 digital telescopes have already been delivered in Europe, Japan, and North America in 2020, delighting customers with an unprecedented observing experience.
Rebecca McDonald, Director of Communications
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Ludovic Nachury, Head of Communication
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