Constrained Reference Star Differential Imaging: Enabling High-fidelity Imagery of Highly Structured Circumstellar Disks ^*

Imaging Circumstellar Debris Disks

In the early 1980s, the Infrared Astronomy Satellite (IRAS) detected thermal emission from dust grains with temperatures of 50-125 K and fractional luminosities (Lgrains/L∗) in the range 10 -10 around four main sequence stars: Vega, Fomalhaut, β Pictoris, and ǫ Eridani. Coronagraphic observations of β Pic confirmed that the grains do indeed lie in a disk, perhaps associated with a young planeta...

I. Direct Imaging of Circumstellar Disks

o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o In the past five years, bservati ns at ptical and near-infrared wavelengths btained with the and gr und-based adaptive ptics have pr vided the first well-res lved images f y ung circumstellar disks, which may f rm planetary systems. We review these tw bservati nal techniques and highlight their results by pres...

NICMOS Imaging of Dusty Circumstellar Disks

Observations of Circumstellar Disks

The imaging of disks around young stars presents extreme challenges in high dynamic range, angular resolution, and sensitivity. Recent instrumental advances have met these challenges admirably, leading to a marked increase in imaging discoveries. These have opened up a new era in studies of the origin of planetary systems. Questions about our own solar system’s formation, and of the prevalence ...

Dynamics of Circumstellar Disks

We present a series of 2-dimensional hydrodynamic simulations of massive disks around protostars. We simulate the same physical problem using both a ‘Piecewise Parabolic Method’ (PPM) code and a ‘Smoothed Particle Hydrodynamic’ (SPH) code, and analyze their differences. The disks studied here range in mass from 0.05M∗ to 1.0M∗ and in initial minimum Toomre Q value from 1.1 to 3.0. We adopt simp...