• Corpus ID: 209376181

The Evolving Coma Morphology of Interstellar Comet 2I/Borisov with Deep HST Imaging

@inproceedings{Bolin2019TheEC,
  title={The Evolving Coma Morphology of Interstellar Comet 2I/Borisov with Deep HST Imaging},
  author={Bryce T. Bolin},
  year={2019}
}

• B. Bolin
• Published 13 December 2019
• Physics, Geology

We present high resolution, deep imaging of interstellar comet 2I/Borisov taken with the Hubble Space Telescope/Wide Field Camera 3 on 2019 October 12, November 16, December 9, 23-25 UTC (Jewitt et al. 2019a; Meech et al. 2019). Deep image stacks of 2I on all dates reveal no discernible signal from a nucleus suggesting that the coma is a strong component of 2I’s total sunlight scattering cross-section. We locate a possible jet-like structure near the optocenter of 2I 1-2′′, or 2,000 3,000 km in length that appears to change positions independent of the orbital velocity and antisolar vectors over the four observation dates indicating possible rotational variation of the morphology but does not show short term variability during the ∼14 orbit, ∼70 h duration of the observations on 2019 December 23-25 UTC. Using the 14 orbit dataset from 2019 December 23-25, we see slight, .0.05 magnitude variation in the brightness of the lightcurve corresponding to a possible double-peaked period of ∼11 h, though the small amplitude variation could be due to short-term changes in the activity of 2I. In addition, we use deep image stacks from the highest spatial resolution observations to estimate a ∼1-2 km diameter consistent with previous high-resolution ground-based observations (Bolin et al. 2019).