Dusty-Gas Cometary Atmosphere Database (DGCAD)

(Version 1.beta)

The atmosphere of a comet (coma) is formed by the sublimation, due to solar illumination, of its volatile component and the dust particles ejected from its nucleus and entrained by the gas flow.

The database contains numerical solutions for a simplified model of a coma given by a heliocentric distance r_h, total gas production rate Q, radius of the nucleus R_N, mass of the nucleus M_n, surface temperature T_n, the variation of relative surface activity q_g∝cos^α(z_sun), level of activity of the night side a_n=q_g(180°)/q_g(0°), dust grain's radius a_d and specific density ϱ_d.

The database provides (via Web interface) dusty-gas coma parameters (dust density and velocity) in the requested coordinates {x,r} (see The reference frame section). The format of the output is: x[m] r[m] rho[kg/m3] vx[m/s] vr[m/s] (if point is outside the computational domain rho=vx=vr=-1.0).

The primary purpose of these model is engineering estimations i.e. rather rough with minimum number of input parameters.

This model is able to reproduce typical spatial distribution of gas and dust density in a coma and better conform the physics of a real cometary atmosphere than the frequently used model of spherical expansion.

Web interface of the database

Physical model

DGCAD is a part of the Comet Interceptor the Engineering Dust Coma Model and of The Simplified Model of a Dust Environment of the Dust, Field and Plasma - Dust Impact Sensor and Counter (DFP-DISC) instrument onboard Comet Interceptor.

In case of issues or questions, please contact: vladimir.zakharov@obspm.fr