Ground-based observability of Dimorphos DART impact ejecta: photometric predictions

• DOI: 10.1093/mnras/stac1849
• Publication Date: 2022-07-08T23:47:27Z
• Authors: Fernando Moreno; Adriano Campo Bag...; Gonzalo Tancredi; Po-Yen Liu; Bruno Domínguez
• Keywords: Earth and Planetary Astrophysics (astro-ph.EP); numerical [Methods]; Methods: numerical; FOS: Physical sciences; numerical –asteroids; 01 natural sciences; methods; 3. Good health; Asteroids: general; general; 0103 physical sciences; general [Asteroids]; Astrophysics - Earth and Planetary Astrophysics

The Double Asteroid Redirection Test (DART) is a NASA mission intended to crash projectile on Dimorphos, the secondary component of binary (65803) Didymos system, study its orbit deflection. As consequence impact, dust cloud will be ejected from body, potentially forming transient coma- or comet-like tail hours days following which might observed using ground-based instrumentation. Based mass and speed impactor, known scaling laws, total can roughly estimated. Then, with aim provide approximate expected brightness levels coma extent morphology, we have propagated orbits particles by integrating their equation motion, used Monte Carlo approach evolution brightness. For typical power-law particle size distribution index --3.5, radii r$_{rmin}$=1 $\mu$m r$_{max}$=1 cm, ejection speeds near 10 times escape velocity predict an increase $\sim$3 magnitudes right after decay pre-impact some after. That would case if prevailing mechanism comes impact-induced seismic wave. However, most ejecta released at order $\gtrsim$100 $\mathrm{m\; s^{-1}}$, observability event reduce very short time span, one day shorter.