Hunt For Exoplanets Gets A Boost With Release Of 20 Years Worth Of Keck Observatory Data

NASA’s Kepler Space Telescope may be the most well-known instrument helping astronomers in their hunt for alien planets, but it is far from the only one. Another such instrument is the W.M. Keck Observatory in Hawaii, which has, using the High Resolution Echelle Spectrometer (HIRES) mounted atop its 10-meter telescope, made over 61,000 individual measurements of over 1,600 stars over the past two decades.

This treasure trove of data, which contains clues to the existence of over 110 potential exoplanets, has now been made public — along with an open-source software to make sense of the observations, as well as a tutorial to use it — by an international team of astronomers.

In doing so, the researchers, which include astronomers from the Massachusetts Institute of Technology (MIT) and the Carnegie Institution for Science, hope that fresh exoplanet candidates can be discovered in the coming months and years.

“This is an amazing catalog, and we realized there just aren’t enough of us on the team to be doing as much science as could come out of this dataset,” Jennifer Burt, a postdoctoral fellow in MIT’s Kavli Institute for astrophysics and space research, and a member of the team involved in compiling the data, said in a statement released Monday. “We’re trying to shift toward a more community-oriented idea of how we should do science, so that others can access the data and see something interesting.”

The dataset can be accessed here (the tutorial link is on the same page), and the software needed to process the data can downloaded from this website.

“Anyone can download the velocities published on our website and use the open source Systemic software package and try fitting planets from the data. A tutorial on how to use Systemic will be available, too,” team member Gregory Laughlin from Yale University explained.

Unlike Kepler, which detects exoplanets by measuring the dip in their parent stars’ brightness (the transit method), the Keck Observatory’s HIRES instrument looks for signs of alien planets by gauging the effect an orbiting object’s gravity has on its star.

As a planet moves in orbit around a star, the former’s gravity tugs on the latter, changing its radial velocity. HIRES, which is designed to split a star’s light into its component colors, detects these tiny changes, which, more often than not, are indicative of an object locked in orbit around the star.

“HIRES was not specifically optimized to do this type of exoplanet detective work, but has turned out to be a workhorse instrument of the field,” team member Steven Vogt from the University of California, Santa Cruz, said. “I am very happy to contribute to science that is fundamentally changing how we view ourselves in the universe.”

After poring over the observations, the researchers, who provided details of the dataset in a study to be published in the Astronomical Journal, have found over 100 potential exoplanets. This includes one orbiting GJ 411 — which, at just over 8 light-years away, is the fourth-closest star to our solar system.

“I think this paper sets a precedent for how the community can collaborate on exoplanet detection and follow-up,” Johanna Teske from Carnegie’s department of terrestrial magnetism, said. “With NASA's TESS mission on the horizon, which is expected to detect 1000+ planets orbiting bright, nearby stars, exoplanet scientists will soon have a whole new pool of planets to follow up.”