Bibcode
Hanus, Josef; Delbo, Marco; Vokrouhlicky, David; Pravec, Petr; Emery, Joshua P.; Ali-Lagoa, Victor; Bolin, Bryce T.; Devogele, Maxime; Dyvig, Ron; Galad, Adrian; Jedicke, Robert; Kornos, Leos; Kusnirak, Peter; Licandro, J.; Reddy, Vishnu; Warner, Brian D.; Rivet, Jean-Pierre; Vilagi, Jozef
Bibliographical reference
American Astronomical Society, DPS meeting #48, id.#516.08
Advertised on:
10
2016
Citations
1
Refereed citations
1
Description
We apply the convex inversion method to the new optical data obtained by
six instruments together with the already existing observations and
derive convex shape model of low-perihelion near-Earth asteroid (3200)
Phaethon. This shape model is then used as an input for the
thermophysical modeling. We present new convex shape model and
rotational state of Phaethon – sidereal rotation period of
3.603958(2) h and ecliptic coordinates of the preferred pole orientation
of (319, ‑39) with a 5 degree uncertainty. Moreover, we derive its
size (D=5.1±0.2 km), thermal inertia (Γ=600±200 J
m-2s-1/2K-1), geometric visible albedo (pV=0.122±0.008), and
estimate the macroscopic surface roughness by the thermophysical model.
We also estimate the average size of the surface regolith to few
centimeters. The Spitzer emission spectrum of Phaethon is similar to
those of CV/CK carbonaceous chondrite meteorites, match with CI/CM
carbonaceous chondrites is ruled out. We also study the long-term
stability of Phaethon's orbit and spin axis by a numerical orbital and
rotation-state integrator. We find that the Sun illumination at the
perihelion passage during past thousands of years is not connected to a
specific area on the surface implying non-preferential heating.
Considering the most important meteor stream of the Geminids is
associated with Phaethon, we predict that the meteorites dropped by
Geminids are CVs or CKs. We also discuss the possible dynamical link
between Phaethon and Pallas and its collisional family.