May 24, 2016
Figure 1. (Left:) Zoom-in images on HD 95086 b obtained with GPI at the first and last epochs. The magenta crosses show the measured positions (for clarity, the size of the symbol is not representative of the precision). Significant orbital motion is detected within the GPI data. (Right:) Deepest image obtained on HD 95086 with GPI at K1 on April 8, 2015.
Figure 2. Schematic diagram of the HD 95086 system in the sky plane. The positions of HD 95086 b are plotted (black circles – VLT/NaCo L0, red triangles – GPI K1, blue squares – GPI H), as well as a hundred representative orbital fits randomly drawn from the analysis The inner and outer dust rings are indicated as the gray shaded regions (Su et al., 2015). For clarity, the astrometric measurements are also shown within an inset.
Using the Gemini Planet Imager astronomers have successfully monitored the motion of a planet around the forming exoplanet system orbiting the star HD 95086 and suggest that more unseen planets are present.
The large international team, led by Julien Rameau, a postdoctoral researcher at the Université de Montréal (Canada), used the Gemini Planet Imager (GPI) at the Gemini South telescope in Chile to observe the system over a period from 2013 until early this year. “During this short time we directly imaged the exoplanet, known as HD 95086 b, a 4-5 Jupiter mass planet, and its motion,” says Rameau. With these data, Rameau and his team determined that this planet is orbiting nearly face-on from our perspective, at about 60 astronomical units or twice the distance between our Sun and Neptune, and it has a low eccentricity, or nearly circular, orbit. Rameau adds, “This extremely high-resolution imaging with GPI was critical to setting constraints on the overall system.” They suggested that this planet could not be responsible for the 50au-wide gap in the system’s debris disk inferred from previous observations in the infrared. ”Because of the orbital configuration of planet b, we conclude that another body, or bodies, are necessary to explain the architecture of the system”
The team’s results are to be published in The Astrophysical Journal Letters (preprint on astro-ph).
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Gemini’s mission is to advance our knowledge of the Universe by providing the international Gemini Community with forefront access to the entire sky.
The Gemini Observatory is an international collaboration with two identical 8-meter telescopes. The Frederick C. Gillett Gemini Telescope is located on Mauna Kea, Hawai’i (Gemini North) and the other telescope on Cerro Pachón in central Chile (Gemini South); together the twin telescopes provide full coverage over both hemispheres of the sky. The telescopes incorporate technologies that allow large, relatively thin mirrors, under active control, to collect and focus both visible and infrared radiation from space.
The Gemini Observatory provides the astronomical communities in six partner countries with state-of-the-art astronomical facilities that allocate observing time in proportion to each country’s contribution. In addition to financial support, each country also contributes significant scientific and technical resources. The national research agencies that form the Gemini partnership include: the US National Science Foundation (NSF), the Canadian National Research Council (NRC), the Chilean Comisión Nacional de Investigación Cientifica y Tecnológica (CONICYT), the Australian Research Council (ARC), the Argentinean Ministerio de Ciencia, Tecnología e Innovación Productiva, and the Brazilian Ministério da Ciência, Tecnologia e Inovação. The observatory is managed by the Association of Universities for Research in Astronomy, Inc. (AURA) under a cooperative agreement with the NSF. The NSF also serves as the executive agency for the international partnership.