GeminiFocus October 2017 | Page 9

Peter Michaud Astronomers Feast on First Light From Gravitational Wave Event Gemini Observatory “pulled out all the stops” to bring a gravitational wave source into focus and capture early optical and infrared light from the merger of two neutron stars. The critical ground-based observations spanned almost a month during the summer of 2017 and allowed astronomers to dissect the first electromagnetic light emissions ever associated with a gravitational wave event. Note: The following story is adapted from the Gemini Observatory press release issued on October 16, 2017. The original release (with videos and additional im- ages) is available online. Figure 1. Astronomers Mansi Kasliwal of Caltech (above) and Edo Berger of Harvard (below) spoke with much excitement about gravitational waves, and the role Gemini played in understanding them, in their videos describing the 2017 summer observation event and its significance. The videos can be found here. Video credits: Caltech and Harvard University The first-ever detection of optical and infrared light linked to a gravitational wave event initiated a time-critical sequence of observations at the Gemini South telescope in Chile. “Gemini pulled out all of the stops to get these data,” said Ryan Chor- nock of Ohio University who analyzed the resulting flood of data in his team’s study of the event. The Gemini data allowed multiple research teams to form a complete picture of the af- termath from the gravitational wave event (GW170817) local- ized by the Laser Interferometer Gravitational-wave Observa- tory (LIGO), Virgo interferometer, and Fermi Gamma-ray Space Telescope on August 17, 2017. The Gemini imaging and spec- troscopy spanned a period of 25 nights — while the object’s light gradually faded from view. Researchers from around the world announced their results on October 16th at press conferences in Washington D.C., Caltech, and one hosted by the European Southern Observatory in Eu- rope. Well over a dozen papers have also been accepted for publication in the journals Nature, Science, and The Astrophysi- cal Journal Letters. October 2017 GeminiFocus 7