Astronomy:Exoplanetary Circumstellar Environments and Disk Explorer

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Short description: Planned space telescope
Exoplanetary Circumstellar Environments and Disk Explorer
Mission typeSpace observatory
Websitesoweb.as.arizona.edu/~gschneider/EXCEDE_OVERVIEW.html
Mission duration3 years nominal (proposed)[1]
Orbital parameters
Reference systemGeocentric
RegimeSun Synchronous
Semi-major axis2,000 km
Inclination105°
Period127 min
Main
Diameter70 cm (28 in)[1]
Instruments
Imaging polarimeter
Explorers program[1]
 

Exoplanetary Circumstellar Environments and Disk Explorer (EXCEDE) is a proposed space telescope for NASA's Explorer program to observe circumstellar protoplanetary and debris discs and study planet formation around nearby (within 100 parsecs) stars of spectral classes M to B.[1] Had it been selected for development, it was proposed to launch in 2019.

The spacecraft concept proposed to use a 70 centimeter diameter telescope-mounted coronagraph called PIAA (Phase Induced Amplitude Apodized Coronagraph) to suppress starlight in order to be able to detect fainter radiation of circumstellar dust.[1] Characterizing constitution of such disks would provide clues for planetary formation (mostly in habitable zones), while already existing exoplanets can be detected through their interaction with dust disk. The project's Principal Investigator is Glenn Schneider.[1]

Science goals

The science goals of the concept mission are: [1]

  • Explore the amount of dust in habitable zones
  • Determining if such a disk interferes with future planet finding missions (dust-scattered starlight causes noise in images of exoplanets[2])
  • Determine composition of material delivered to planets: icy and organich-rich particles are important for life.[3]
  • Determine fraction of massive planets on large orbits
  • Observe how protoplanetary disks make Solar System-like architectures
  • Constrain giant planets' composition by measuring their reflectivity[4] EXCEDE would be the first to image (giant) exoplanets distances from their stars similar to ours (0.5-7 AU).[5]

References