Space is hard, and our understanding only advances in two ways – through major breakthroughs that require luck and creativity to recognize, and with the slow and steady advancement of better instruments that allow us to uncover details that had previously been just out of sight. Sometimes, this slow-and-steady progress allows us to discover that the “is that a signal or is that noise” blips in our data are actual signals, and this can be both satisfying and frustrating to folks who have spent years and decades trying to force discoveries out of too small telescopes. 

This is the case for the research of Fritz Benedict and Barbara McArthur, who spent decades using the telescopes of McDonald Observatory, the Hubble Space Telescope, and other missions and ground-based systems to try and discover planets by looking for the on-the-sky motions of their stars. This technique has really only become possible now that we have the Gaia space telescope, but I remember hearing talks in grad school where Fritz was able to put limits on “these kinds of planets don’t exist, but these kinds still could be there”. His targets were nearby stars like Bernard’s star and Proxima Centauri. Well, as we discussed recently, the ESPRESSO instrument on the Very Large Telescope has used spectroscopy to determine there are planets. With this high-quality data in hand, Fritz has gone back through 25 years of Hubble data, something that reminded me I am old since I remember the first talks he gave, and in this data, he was able to see these now confirmed worlds in his noise. These were datapoints no one could have used to say “There be planets!”, not by themselves, but they are enough to say now, “We can confirm the orbits with greater precision with this long baseline.” What’s more, with today’s new data, they were able to find a new third planet in this system with an extremely long orbital period and a mass just seven times Earth’s mass. This story once again shows there is no expiry date on data.

More Information

McDonald Observatory press release