Comets and Asteroids

Exocomet Models in Transit: Light Curve Morphology in the Optical — Near Infrared Wavelength Range

By Keith Cowing
Status Report
May 24, 2024
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Exocomet Models in Transit: Light Curve Morphology in the Optical — Near Infrared Wavelength Range
Synthetic, monochromatic light curves of a comet with narrow tail, plotted for the three selected grain size distributions, labelled as a ∼ 2 µm (top row), 650 nm (middle row) and 200 nm (bottom row), for an A star. Columns denote the materials used in the simulations: carbon (left), graphite (second from the left), pyroxene (second from the right), and olivine (right). Note the change in the scale of the y axis from row to row. — astro-ph.EP

Following the widespread practice of exoplanetary transit simulations, various presumed components of an extrasolar system can be examined in numerically simulated transits, including exomoons, rings around planets, and the deformation of exoplanets.

Template signals can then be used to efficiently search for light curve features that mark specific phenomena in the data, and they also provide a basis for feasibility studies of instruments and search programs.

In this paper, we present a method for exocomet transit light curve calculations using arbitrary dust distributions in transit. The calculations, spanning four distinct materials (carbon, graphite, pyroxene, and olivine), dust grain sizes (100\,nm — 300\,nm, 300\,nm — 1000\,nm, and 1000\,nm — 3000\,nm) encompass light curves in VRJHKL bands. We also investigated the behavior of scattering colors.

We show that multicolor photometric observations are highly effective tools in the detection and characterization of exocomet transits. They provide information on the dust distribution of the comet (encoded in the light curve shape), while the color information itself can reveal the particle size change and material composition of the transiting material, in relation to the surrounding environment.

We also show that the typical cometary tail can result in the wavelength dependence of the transit timing. We demonstrate that multi-wavelength observations can yield compelling evidence for the presence of exocomets in real observations.

Szilárd Kálmán, Gyula M. Szabó, Csaba Kiss

Comments: 26 pages, 20 figures. Accepted for publication in Publications of the Astronomical Society of the Pacific
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2405.13663 [astro-ph.EP] (or arXiv:2405.13663v1 [astro-ph.EP] for this version)
Submission history
From: Szilárd Kálmán
[v1] Wed, 22 May 2024 14:06:56 UTC (2,281 KB)
Astrobiology, Astrochemistry,

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻