Skip to main content
SearchLoginLogin or Signup

Determining solar wind flow speeds from stationary-point measurements with WISPR

Presentation #109.06 in the session Tracking Plasma Flows in the Heliosphere.

Published onOct 20, 2022
Determining solar wind flow speeds from stationary-point measurements with WISPR

The WISPR instrument on Parker Solar Probe offers the first up-close view of the young solar wind, from a rapidly-changing field of view caused by the high velocity of the spacecraft and its close proximity to the structures being imaged. This unique vantage enables new types of analysis. We develop one such analysis, using the changing field of view as a tool to measure the outflow velocity of the solar wind near the spacecraft at heliocentric distances comparable to PSP’s own position. Amid the outflowing plasma visible in WISPR image sequences, we detect the “stationary point,” a position in the field of view where plasma features do not move in the image plane. This indicates plasma which will collide with or pass near the spacecraft, as that plasma is on an inward trajectory in the spacecraft frame. The angular position of this stationary point is a function of the known spacecraft velocity and the unknown plasma velocity, allowing the plasma velocity to be determined in neighborhoods of varying size near the spacecraft, complementary to in situ measurements at the spacecraft itself. This will help answer open questions regarding the nature and early evolution of the young solar wind. In this presentation, we will discuss the development of our technique and show initial results.

Comments
0
comment

No comments here