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Title: CHARACTERIZING THE ATMOSPHERES OF THE HR8799 PLANETS WITH HST/WFC3

We present results from a Hubble Space Telescope (HST) program characterizing the atmospheres of the outer two planets in the HR8799 system. The images were taken over 15 orbits in three near-infrared (near-IR) medium-band filters—F098M, F127M, and F139M—using the Wide Field Camera 3. One of the three filters is sensitive to a water absorption band inaccessible from ground-based observations, providing a unique probe of the thermal emission from the atmospheres of these young giant planets. The observations were taken at 30 different spacecraft rolls to enable angular differential imaging (ADI), and the full data set was analyzed with the Karhunen–Loéve Image Projection routine, an advanced image processing algorithm adapted to work with HST data. To achieve the required high contrast at subarcsecond resolution, we utilized the pointing accuracy of HST in combination with an improved pipeline designed to combine the dithered ADI data with an algorithm designed to both improve the image resolution and accurately measure the photometry. The results include F127M (J) detections of the outer planets, HR8799b and c, and the first detection of HR8799b in the water-band (F139M) filter. The F127M photometry for HR8799c agrees well with fitted atmospheric models, resolving the longstanding difficulty in consistently modelingmore » the near-IR flux of the planet.« less
Authors:
;  [1] ;  [2] ; ; ; ;  [3] ;  [4] ;  [5] ;  [6]
  1. School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85282 (United States)
  2. Department of Planetary Sciences and Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721 (United States)
  3. Space Telescope Science Institute, Baltimore, MD 21218 (United States)
  4. Dunlap Institute for Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4 (Canada)
  5. Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305 (United States)
  6. National Research Council of Canada Herzberg, Victoria, BC V9E 2E7 (Canada)
Publication Date:
OSTI Identifier:
22518901
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 809; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABSORPTION SPECTRA; ALGORITHMS; CAMERAS; DETECTION; IMAGE PROCESSING; IMAGES; MASS; NEAR INFRARED RADIATION; PHOTOMETRY; PLANETARY ATMOSPHERES; PLANETS; RESOLUTION; SPACE; SPACE VEHICLES; STARS; TELESCOPES; WATER