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Session 10 - NICMOS.
Display session, Wednesday, January 07
Exhibit Hall,
The Near Infrared Camera and Multi-Object Spectrometer (NICMOS) on the Hubble Space Telescope includes a coronagraph in the f/45 camera. Under the HST Guaranteed Time Observing program the NICMOS IDT will be carrying out coronagraphic imaging surveys of selected M-dwarfs, young stars and main sequence stars with IR excesses to search for brown dwarf and giant planet companions, and protoplanetary disks. The performance levels of the NICMOS coronagraph were determined during the on-orbit instrumental calibration carried out the Servicing Mission Observatory Verification phase of the mission. To obtain optimal performance in lowering both the diffracted energy in the regions surrounding bright star, by reducing the high spatial frequency components of the occulted core of the PSF, and down stream scattering a number of adjustments were made to coronagraphic operations. With those improvements in place we will be able to reduce the background from the unocculted wings of a centrally occulted stellar PSF by factors of 1E-5 near the edge of the coronagraphic hole (375 mas radius) to 1E-6 at 1" using a differential imaging strategy. Details of the calibration and performance levels of the NICMOS coronagraph and their implications for our GTO coronagraphic science programs are presented.
