Comet Dust Tail Simulator/Solver
Finson & Probstein 1968
About

Interactive Finson–Probstein dust-tail simulator with sky-plane projection, HORIZONS vectors, and FITS-based fitting. The workflow is stepwise:

  1. Load Image: Load a FITS file in the browser. The file must include WCS headers (CRVAL/CRPIX/CDELT or CD). If your FITS lacks WCS, solve the image in ASTAP and write the headers before loading.
  2. Extract Observer: Use the FITS observer metadata to populate the observer geometry and map.
  3. Target: Enter the comet designation or pick from the library. This sets the target used for HORIZONS queries.
  4. Query HORIZONS: Fetch the comet and Sun vectors (and elements) at Tobs to enable sky-plane projection.
  5. Solve Model: Fit emission times and beta values against the empirical image; results populate the plot and outputs.

The diagram shows synchrones and syndynes with RA/Dec offsets, and the JSON/CSV/Matplotlib exports provide reproducible outputs.

Steps

Ready.
Solve Details
No solve run yet.

Orbital Elements

Manual Simulation

Simulation

Baseline FP model: dust released in orbital plane with zero ejection velocity; motion under (1 − β) solar gravity.
Comma-separated days from Tobs. Use the checkbox to interpret as days before.
β is radiation pressure / gravity. Typical dust: 0.001–0.5.
Components in m/s, applied at emission time.
Integration steps below 0.5 day can be numerically unstable.
Normal component affects 3D positions and JSON but is not visible in a 2D orbital-plane view.

Empirical Image

Parsed in browser memory only.
No FITS loaded.
Auto: --
Solving requires Sky-plane display and valid WCS in the FITS header.

Observer Geometry

Sky-plane projection uses the observer–comet vector from HORIZONS. If the query fails, sky-plane mode will be disabled.

Diagram

Tilt: --
Synchrones Syndynes Sun Velocity
JSON link
[1] C. C. Finson and R. F. Probstein, “A theory of dust comets,” The Astrophysical Journal, vol. 154, p. 327, 1968.
If you use this tool in your work please cite:
A. Phillips, “Comet Dust Tail Simulator/Solver,” Carleton University, 2025. Available: https://adonphillips.com.
Show BibTeX 
@misc{phillips2025comet,
  author = {Phillips, A.},
  title = {Comet Dust Tail Simulator/Solver},
  institution = {Carleton University},
  year = {2025},
  url = {https://adonphillips.com},
  note = {Local web application}
}