Constraining the Architecture of the HD 95086 Planetary System
New observations obtained using the Gemini Planet Imager ( GPI ) on the Gemini South telescope , combined with earlier data , provide more quantitative information about the confirmed exoplanet that the star HD 95086 hosts and suggest the presence of multiple planets . Julien Rameau ( Université de Montréal , Canada ) and colleagues directly observed the planet , called HD 95086 b , and determined its orbital parameters . They find the orbital semimajor axis around 62 astronomical units and low eccentricity ( ε < 0.21 ).
July 2016
The star ’ s debris disk , where such young planets form , produces additional infrared emission . Considering multiple pieces of evidence , the architecture of this system — including the disk , its gaps , and the confirmed exoplanet — likely requires another planet or more in addition to HD 95086 b to explain the observations . See more about this work at the Gemini webpage . The work has been published in The Astrophysical Journal Letters .
N159W : Dissecting Triggered Star Formation with MCAO
Massive stars ( greater than eight solar masses ) shape their surroundings by ionizing the local interstellar medium to create expanding Hii regions , which may compress nearby gas and enhance local star formation . Observing this starbirth in situ presents a challenge because dust hides the strong ultraviolet and optical emission of the newborn stars , and all the activity occurs on very small spatial scales . PhD student Anaïs Bernard ( Laboratoire d ’ Astrophysique de Marseille , France ) and collaborators have used the Gemini Multi-conjugate adaptive optics System ( GeMS ) with the Gemini South Adaptive Optics Imager ( GSAOI ) to overcome these difficulties .
Figure 4 shows the result . The image reveals fine details ( on scales of ~ 0.09 arcsecond ) in the near-infrared light that penetrates the obscuring dust of N159W , a young star-forming region located ~ 150,000 light years distant in the Large Magellanic Cloud . The 100 young stellar object ( YSO ) candidates associated with N159W lie mostly at the border of the ionized ( Hii ) bubble — where cold , neutral material accumulates in clumps and subclusters — and displays signs of recent active star formation . In contrast , the estimated age of the two ( blue ) massive stars and the associated cluster at the bubble ’ s center is about two
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Figure 2 . A deep K1-band image of HD 95086 from GPI clearly shows a planet , located at about the 7-o ’ clock position and within 0.5 ” of the central star .
Figure 3 . This schematic diagram shows observed locations of the planet HD 95086 b ( black and red points , with error bars ) and numerical simulations of possible orbits ( blue lines ). Gray shaded regions mark the locations of inner and outer dust rings .