In recent years, the topic of exoplanets has dominated popular media related to Astronomy. Almost every week, media outlets report new discoveries about exoplanets, especially those in the habitable zone that could support life. However, these types of planets are generally small compared to their host star, so their influence on the star is difficult to detect. The changes in velocity that small planets impart on their host can be as low as ~1 to 3 meters per second, about walking speed.

In order to address this challenging issue, Dr. Rob Wittenmyer, a senior lecturer from the University of New South Wales, introduced the cleverly-named MINERVA (MINiature Exoplanet Radial Velocity Array) project in a lecture at NAOC on July 1, 2014 about detecting small planets around stars nearby. He explain that from the initial results of the Kepler mission, our Galaxy is teeming with small planets. He described the telescopes and related equipment for the MINERVA project that are located at the Whipple Observatory on Mt. Hopkins, Arizona and showed photographs and diagrams of the equipment that is currently installed or being tested. When the project begins operation later this year, it will incorporate four separate telescopes whose light will be combined into an effective meter-class telescope and directed into a sensitive spectrometer where small changes in velocity can be observed. Wittenmyer explained that purchasing four smaller telescopes and operating them in unison is far less expensive than acquiring a single meter-class telescope for this study. Moreover, he described how having a very thermally-stable spectrometer is important for this research, since tiny changes in temperature or pressure could influence measurements of spectral lines needed to detect changes in motions of the host star due to small planets. The project will concentrate on G and K type stars that are relatively stable and nearby, making detection easier. He mentioned that, although other types of stars might be brighter, they can also have large oscillations that mask effects of planets. Dr. Wittenmyer emphasized that, because this project will directly control the telescopes, they will not have to share time with other researchers at a larger facility, and the managers of this project can apply the “brute force” needed to collect large amounts of data on these targets to uncover the motions of small planets.

Dr. Wittenmyer declared that almost every star has planets and there are more small planets than large planets, so he expects that many small planets will be found in this study. The initial phase of the MINERVA project will last three years and concentrate on the closest stars that satisfy the criteria of being targets. Data will continue to be collected in subsequent years, helping to find even smaller motions of stars that are caused by planets. In addition, MINERVA can follow up discoveries by the upcoming Transiting Exoplanet Survey Satellite (TESS) mission. More information about the MINERVA project can be found at: http://www.astro.caltech.edu/minerva/Home.html.