See what we have achieved together!
The global Unistellar community observes gas-giant exoplanets with poorly known orbits as part of our NASA-sponsored research program. Astronomers at the SETI Institute gather information about an exoplanet’s size and orbit from these observations, which capture the planet blocking out a portion of its star’s light in an event called a transit. With better understanding of a planet’s path around its sun, scientists can deduce what characteristics the exoplanet may have. This important work not only helps to piece together the general puzzle of planet formation, but may help mankind to better understand the cosmic beginnings of our own Solar System.
NASA-Sponsored Exoplanet Observation: TOI 1812.01
In the first of several NASA-sponsored exoplanet hunts in 2022, Citizen Astronomers searched for a transit of TOI 1812.01. This planet, the outermost of three gaseous planets around a relatively cool star, is Saturn-sized with its radius nine times the size of Earth’s. Despite having two transits observed by TESS, its period (the length of its year) was poorly known: previous estimates ranged from 71 – 157 days. To nail down the orbit, 20 Citizen Astronomers tracked TOI 1812.01 for three nights over the course of two months. Only on the third night, August 27, did they spot the exoplanet and confirm that it takes 112 days to orbit its star.
NASA-Sponsored Exoplanet Observation: TOI 4465.01
In another exoplanet endeavor, 23 Unistellar observers watched exoplanet TOI 4465.01 over three continuous nights in search of a transit. Cumulatively, they logged an astounding 230 hours of observations and ultimately caught the transit signature. One Japanese observer in the Unistellar community even caught the egress of the transit, an important part of the lightcurve where the planet finishes crossing in front of its star. This egress timing matches up with other observations taken of the planet, confirming the Unistellar Network’s results. The period of TOI 4465.01 was not well-known until now, and the data from the Unistellar community helped to place the final piece in its puzzle.
“Roasted Planet” Detection Supports Future JWST Observation
The “Roasted Planet”, aka HD 80606 b, passed in front of its star in December of 2021, giving seven Unistellar network members the opportunity to become the only citizen astronomers to observe the entire transit. This Jupiter-sized exoplanet travels incredibly close to its sun due to its oblong orbit, heating it up to thousands of degrees and creating planet-wide shockwave storms. Since HD 80606 b is on JWST’s target list, these observations saved the space telescope some valuable time by better preparing professional astronomers to observe this scorched world.
Setting Records with Kepler-167e
During a 32 hour window during November 2021, 31 Unistellar citizen astronomers from around the world collected 43 observations of Kepler-167 e, a Jupiter-like exoplanet with a 1,071 day orbit. This campaign set the record for the longest period exoplanet to ever have a full transit detected from ground-based telescopes. The transit itself lasted over 16 hours! Kepler-167 e set the stage for the Unistellar Network to be able to observe long-duration transits like those featured in our NASA-sponsored programs.
- Exoplanet: A planet outside of our own Solar System. Over 5,000 exoplanets are known so far.
- 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!
- Light Curve: A plot of a celestial body’s light intensity, which shows how the light from that object changes over time. In the case of exoplanets, we look at a star’s light curve. As the exoplanet passes in front of the star as seen from Earth, it temporarily blocks some of the star’s light. Studying the shape and timing of the light curve can tell astronomers about an exoplanet’s characteristics.
- TESS: Transiting Exoplanet Survey Satellite, NASA’s current exoplanet exoplanet finding mission.
- TOI: TESS Object of Interest. An exoplanet candidate discovered by TESS, which may be a planet but requires additional observations to be confirmed as a definite exoplanet and not a false signal.
- Kepler: The predecessor to TESS, NASA’s Kepler space telescope discovered over 2,600 transiting exoplanets between 2009 and 2022.
- Full Detection: A light curve complete with measurements from before the transit started until after it ended, showing a dip in the star’s brightness that has a high likelihood (>99%) of being from the transit and not a false alarm from noise in the data.
- Partial Detection: An incomplete light curve containing measurements from only the beginning or end of a transit, showing a brightness dip with a high likelihood of being real.
- Joint Detection: A light curve, often incomplete or of low significance, that shows a full detection when combined with other light curves.