Infrared coronographic imaging of circumstellar material around 55 Cancri. On the left is an H filter image, 58 min total integration time (29 coadds of 2 min exposures). On the right is the H filter total image, contoured with the best fit ellipse and major and minor axes overlain. The circle in the center of the image is the corongraphic mask which has a diamter of 3 arcseconds. The image is approximately 15 arcseconds on a side at a plate scale of 0.055 arcseconds per pixel. North is up and East is to the left. The faint vertical and horizontal lines emanating from the coronographic mask are the remnants of the diffraction patterns of the telescope spiders which are used to help register the images. The repeating-pattern spots represent cosmic ray hits in the flat-field frame; the clusters result from the slight, repeated shifts used in co-aligning the corongraphic images, causing a cosmic ray hit to show up as a cluster in the fully processd data. The contour interval on the left is 0.83 mJy per arcsecond squared, with a lowest contour of 1.11 mJy per arcsecond squared. The ellipse is roughly fit to the outermost contour drawn in this images (1 Jy = 1e-12 W/m*m/µm at H band.)

(Adapted from Trilling & Brown 1998.)

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