Miguel Rubio and his father, Cesar, talk a lot about space. But they’ve also turned that interest into a productive collaboration that helped discover a new planet.
The elder Rubio’s spare time includes volunteering with a NASA-funded “citizen science” project seeking strange new worlds outside the solar system. The project, called Planet Hunters Transiting Exoplanet Survey Satellite (TESS), recently announced more than a dozen citizen scientists — including Miguel Rubio — helped professionals uncover two new worlds.
“I try to nurture that [interest],” Rubio said in a statement of talking about space with his son. Rubio’s day job is working as a machinist in Pomona, California, which is only a half-hour drive from NASA’s Jet Propulsion Laboratory. The Los Angeles region is therefore full of space opportunities for the Rubio family, including some real-life spacecraft on display at the California Science Center.
The planets will be something very interesting for the Rubio family to discuss, because these are worlds a bit bigger than Earth, orbiting a star not too much larger or brighter than our sun. Planet b is roughly the size of Neptune (four times that of Earth) while Planet c is roughly six times bigger than Earth, kind of like a “sub-Saturn.”
Rubio and other participants in Planet Hunters TESS spotted a distinctive dimming of the star’s light, suggesting (which was correct) some planets orbiting close to their home stars. Some of the citizen scientists also brought the discussion to the online forum to flag the professional astronomers, who also could see the results in the data.
To be sure, machine learning algorithms could help with the search — but computers are still better at it, which is why Planet Hunters asks for volunteer help. Those that make a discovery, like the Rubio family, are credited alongside the professional astronomers for their help. The scientists figured out which of the dimmings to follow first by ranking the best-performing “light curves” from planets passing across their home star.
Sometimes light curves can happen due to dust, or sunspots, so you have to check potential planets out with other observatories. In this case, the science team performed more observations using an instrument called HARPS-N (the High Accuracy Radial velocity Planet Searcher for the Northern hemisphere) at the Telescopio Nazionale Galileo in La Palma, Spain, as well as EXPRES (the Extreme Precision Spectrometer), an instrument at Lowell Observatory in Flagstaff, Arizona.
Unlike the TESS spacecraft that found the initial light curves, the two other telescopes look at gravitational wobbles that planets induce in their parent stars. In some cases, you can also figure out the mass of the planet with this technique, although the current study did not have conditions clear enough to produce a precise signal. (That means that all the masses are estimates and may be refined with more work.)
A little further in the future, citizen scientists might be looking at light curves from planets that could be about the size of Earth. NASA’s James Webb Space Telescope will launch later this year to study the atmospheres of big planets, and more observatories are in development to seek out even smaller worlds, like the European Extremely Large Telescope.
A study based on the research was recently published in the Monthly Notices of the Royal Astronomical Society.