Help Privacy Policy Disclaimer
  Advanced SearchBrowse




Journal Article

Hubble Space Telescope Observations of 3200 Phaethon at Closest Approach


Agarwal,  Jessica
Department Planets and Comets, Max Planck Institute for Solar System Research, Max Planck Society;

External Resource
No external resources are shared
Fulltext (restricted access)
There are currently no full texts shared for your IP range.
Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)
There is no public supplementary material available

Jewitt, D., Mutchler, M., Agarwal, J., & Li, J. (2018). Hubble Space Telescope Observations of 3200 Phaethon at Closest Approach. The Astronomical Journal, 156(5): 238. doi:10.3847/2041-8213/aaee10.

Cite as: https://hdl.handle.net/21.11116/0000-0003-A2D8-2
We present Hubble Space Telescope observations of the active asteroid (and Geminid stream parent) 3200 Phaethon when at its closest approach to Earth (separation 0.07 au) in 2017 December. Images were recorded within ~1° of the orbital plane, providing extra sensitivity to low surface brightness caused by scattering from a large-particle trail. We placed an upper limit on the apparent surface brightness of such a trail at 27.2 mag arcsecond−2, corresponding to an in-plane optical depth ≤3 × 10−9. No co-moving sources brighter than absolute magnitude 26.3, corresponding to circular equivalent radius ~12 m (albedo 0.12 assumed), were detected. Phaethon is too hot for near-surface ice to survive. We briefly consider the thermodynamic stability of deeply buried ice, finding that its survival would require either a very small (regolith-like) thermal diffusivity (<10−8 m2 s−1), or the unexpectedly recent injection of Phaethon (timescale lesssim106 years) into its present orbit, or both.