Successful Exoplanet Results from Unistellar Citizen Astronomers

Unistellar citizen astronomers' observations presented at NASA TESS conference

Exoplanet candidate transit observations by Unistellar citizen scientists were presented in a poster at the second TESS Science Conference on August 2–6, 2021. Click on the image to the left to see an overview of this ongoing program and the results of measurements made from eVscope data to help confirm the orbits and nature of newly discovered candidate exoplanets from NASA’s TESS mission. Here is a link to the high resolution poster and video explaining it by SETI Institute astronomer and Unistellar Space Science Principal, Tom Esposito.

Unistellar observations in the public AAVSO Exoplanet Database

Visit the AAVSO Exoplanet Database to find over 20 exoplanet transit detections that Unistellar citizen scientists have contributed to that public data repository so astronomers can better understand planets in our galaxy. (Search for Observer Code “UNIS” to find Unistellar entries.) Anyone can contribute light curve data to this database by creating a free user account at

Highlight: Results from eVscope observations of exoplanet HD 189733b


HD 189733b Exoplanet Artist's View


On November 6, 2020 Unistellar citizen astronomers observed exoplanet HD 189733b pass in front of (or transit across) its star!

HD 189733b is a hot, Jupiter-sized exoplanet that orbits its star every 2.2 days. It is 13% more massive than Jupiter and its winds blow 7 times the speed of sound!

Interestingly, it was the first exoplanet to have its color measured! Its blue color doesn’t come from oceans of water on its surface but possibly from a hazy atmosphere with clouds full of tiny glass shards. Read more about these observations of this “true blue planet.”

“By combining 3 citizen astronomers’ eVscope observations from across Europe, we timed HD 189733b crossing its star to within a couple of minutes, 63 light-years from Earth!,” said Tom Esposito, lead exoplanet astronomer with the SETI Institute & the Unistellar Exoplanet Team.

The three observations were made by Unistellar citizen astronomers Mario Billiani (Austria), Stephan Abel (Germany), and Julien de Lambilly (Switzerland).

Transit light curves like this one are used to visualize an exoplanet transit from collected data. This light curve shows the transit of HD 189733b, which caused the flux (brightness) of that planet’s host star to dim and then return to normal. The gray circles and blue squares on the larger plot indicate the brightness of the star measured over time, which was compared with an astronomical model (the red line) to estimate the planet’s properties. This shows that the star dimmed by 2.8% (the dip along the plot’s vertical axis) as HD 189733b transited it. The depth of this dip tells us the planet’s size as compared to the star. The smaller plot below shows how well the data matched the astronomical models (near zero is a good match).


The animation above illustrates how the three individual “light curves” were merged into one combined light curve.

All three individual observations were consistent with previous observations of this planet made by 10 professional-grade telescopes in 2005 & 2006, which is pretty impressive for a 4.5-inch telescope that can collect scientific data right from your backyard!

Esposito added, “Also, combining the eVscope observations led to a more precise measurement of the transit’s timing than using individual observations, which shows great promise for future cooperative science with the growing Unistellar Network!”

“It’s like in the old cartoon: with your powers combined… we are Captain Planet!”

Unistellar partners closely with the SETI Institute, which includes a great team of exoplanet scientists. Many thanks to the SETI Institute & the Unistellar Exoplanet Team: Tom Esposito, Dan Peluso, and Arin Avsar for planning this observation, analyzing the data, and sharing these great results with us!


Testimonials from Unistellar Citizen Astronomers


Mario Billiani eVscope Unistellar Citizen Astronomer

Mario Billiani, Unistellar Citizen Astronomer from Austria

“This was my first successful detection of an exoplanet with my eVscope so this campaign result is of particular value to me. I also appreciate that we could combine the light curve with two other simultaneous observations to improve the data.”


Stephan Abel eVscope Unistellar Citizen Astronomer

Stephan Abel, Unistellar Citizen Astronomer from Germany

“The observation of the HD 189733 b transit was the first opportunity my eVscope had to be used in a Unistellar citizen science project. My first problem was to find a suitable observation site. Light pollution in the southwest of Germany is generally high, and I live near Koblenz, where this is even more pronounced.

So I chose a viewing platform for hikers about 20 km from my apartment, near the village of Rüscheid.

This is located in a field, so I had to carry my eVscope about 500m there, but thanks to my backpack and low weight, it was no problem!

The weather was cool and windy, I was very happy that I had warm clothes and hot tea with me. Also were two horses in the paddock, eyeing me curiously. Otherwise there were no spectators. I am fascinated by the sight of starry skies every time, even if a lot cannot be seen with the eyes in Bortle class 4 area.

It was pure luck that I bought the eVscope in August. I hadn’t heard of it before, but I wanted to get a telescope again.

In my youth I owned a 6 ” Newtonian telescope, an entry-level model, difficult to handle.

I was immediately convinced of the design of the eVscope, as it is easy to use and easy to transport in combination with digital optics which are crucial for hobby astronomy.”

Originally translated from German:

“Die Beobachtung des Transit von HD 189733 b war die erste Gelegenheit mein EVScope im Citizensience Projekt von Unistellar zu nutzen. Mein erstes Problem bestand darin einen geeigneten Beobachtungsort zu finden. Im Südwesten Deutschland’s ist die Lichtverschmutzung allgemein hoch, und ich wohne in der Nähe von Koblenz, wo diese sich noch störender bemerkbar macht.

Ich wählte daher eine Aussichtsplattform für Wanderer etwas 20 km von meiner Wohnung, bei dem Dorf Rüscheid.

Diese ist auf einem Acker gelegen, daher musste ich mein EVScope noch etwa 500m dahin tragen, aber Dank Rucksack und kleinem Gewicht kein Problem!

Das Wetter war kühl und windig, ich war sehr froh, dass ich warme Kleidung und heissen Tee dabei hatte. Auch waren zwei Pferde auf der Koppel, und beäugten mich neugierig. Ansonsten gab es keine Zuschauer. Der Anblick des Sternenhimmels fansziniert mich jedes mal, auch wenn bei Bortle Klasse 4 vieles mit dem Auge nicht zu sehen ist.

Es war reiner Zufall, dass ich das mir das EVScope im Auguste kaufte. Ich hatte vorher nichts davon gehört, wollte mir aber ein Teleskop wieder zulegen.

In der Jugend besaß ich ein 6″ Newton Fernrohr, ein Einsteigermodell, schwer zu händeln.

Von dem Design des EVScope war ich sofort überzeugt, da mir einfache Bedienbarkeit und gute Transportfähigkeit in Kombination mit der digitalen Optik für die Hobbyastronomie ausschlaggebend sind.”


Julien de Lambilly eVscope Unistellar Citizen Astronomer

Julien de Lambilly, Unistellar Citizen Astronomer from Switzerland

“The HD 189733b campaign was particularly interesting to me because they wanted to compare the eVscope to research telescopes. I wanted to know how valuable our data could be!

So on November 6, I went to a mountain pass, le Col du Marchairuz at an elevation of 1389m in Switzerland to observe the HD 189733b transit. The sky was clear, Bortle class 4 and there was a lot of humidity, but luckily no wind at all. The temperature went from 4 to 2 degrees Celsius by the end.

I was a bit worried, because this was the first time I’d observed an exoplanet transit on a bright star like HD 189733.

I don’t know why I was worried anyway, Tom Esposito did the maths and told me it would fit just right!

On November 25 we discovered the results on the Unistellar slack channel. It was the first time the exoplanet experts from Unistellar were able to combine the data from different observers! And the light curve looked beautiful and indeed more precise than my own alone. This makes even more sense to work as a community! I’m proud to have participated! Special thanks to Dan Peluso and Tom Esposito for providing the opportunity!”

Exoplanets Detections by Unistellar Telescopes (as of 25/08/2021)

Generated by wpDataTables



  • Exoplanet Candidate: A potential planet outside our solar system that has been discovered by a telescope, but not yet definitively proven to be a planet. Data from Unistellar citizen astronomers’ observations can help confirm these as real planets!
  • TOI: TESS Object of Interest. An exoplanet candidate for the Transiting Exoplanet Survey Satellite (TESS), NASA’s current exoplanet finding mission.
  • HAT: Hungarian-made Automated Telescope. A robotic network of small telescopes in Australia, Chile, Namibia, and the United States to search for transiting exoplanets.
  • KELT: Kilodegree Extremely Little Telescope. Consisting of two telescopes in Arizona, United States and Sutherland, South Africa, its goal is to discover transiting exoplanets.
  • WASP: Wide Angle Search for Planets. A pair of small robotic telescopes at La Palma Observatory, Canary Islands and Sutherland, South Africa to discover transiting exoplanets.