A Look at the Local Interstellar Medium that Encompassed the Sun in Our Recent Past in order to Understand Our Current and Future Interstellar Surroundings
Abstract
The Local Interstellar Medium (LISM) is a rich and complex suite of clouds in the immediate vicinity of the Sun. The Sun is located at the edge of the Local Interstellar Cloud (LIC), the interstellar structure that is thought to directly surround the solar system. We present a global three-dimensional model of the LISM, based on ultraviolet absorption line spectroscopy of hundreds of nearby stars, including a dense survey of stars along the historical solar trajectory. Our 3D model is based on assuming constant neutral hydrogen number density for all clouds, and a tight packing that ensures a warm, partially ionized cloud surrounds stars with known astrospheric detections. We explore the distribution, kinematics, and physical properties of the LIC and other nearby clouds in order to understand how the heliosphere has evolved in our most recent past (e.g., within the last 5 Myr), the properties of the LISM that currently encompass our solar system, and the conditions we may expect to encounter in the immediate future. These measurements provide an invaluable global view of the pristine interstellar material that Interstellar Probe, for the first time, will be traversing. However, our measurements are averaged over the entire line of sight. We will discuss the possible measurements by Interstellar Probe that will provide unique insights into the detailed structure of LISM clouds that determine the heliospheric morphology and evolution.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMSH019..07R
- Keywords:
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- 2124 Heliopause and solar wind termination;
- INTERPLANETARY PHYSICS;
- 2126 Heliosphere/interstellar medium interactions;
- INTERPLANETARY PHYSICS;
- 2129 Interplanetary dust;
- INTERPLANETARY PHYSICS;
- 6224 Kuiper belt objects;
- PLANETARY SCIENCES: SOLAR SYSTEM OBJECTS