Proper Motion

Proper motion refers to the apparent motion of stars across the sky over time as observed from Earth. This motion is caused by the actual motion of the stars through space. It's important to note that proper motion is distinct from the apparent daily motion of stars caused by Earth's rotation.

Stars move due to their individual velocities through the galaxy. This motion can be observed by comparing the position of a star relative to distant, fixed reference points over time. Proper motion is typically measured in arcseconds per year (arcsec/yr), where one arcsecond is 1/3600th of a degree.

The study of proper motion is essential for understanding the dynamics of our galaxy and the universe. It helps astronomers determine the orbits of stars within the Milky Way, identify stars belonging to star clusters or moving groups, and investigate the distribution of mass in the galaxy.

Astronomers use techniques like astrometry, which precisely measures the positions and motions of celestial objects, to determine proper motions. This can be done by comparing images taken at different times, typically using instruments like space telescopes or large ground-based telescopes equipped with advanced cameras.

Proper motion can also be combined with measurements of a star's radial velocity (its motion along the line of sight) to determine its true space velocity relative to the Sun.

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AI Technical Trustability Update

While working on an update to my RF Cafe Espresso Engineering Workbook project to add a couple calculators about FM sidebands (available soon). The good news is that AI provided excellent VBA code to generate a set of Bessel function plots. The bad news is when I asked for a table showing at which modulation indices sidebands 0 (carrier) through 5 vanish, none of the agents got it right. Some were really bad. The AI agents typically explain their reason and method correctly, then go on to produces bad results. Even after pointing out errors, subsequent results are still wrong. I do a lot of AI work and see this often, even with subscribing to professional versions. I ultimately generated the table myself. There is going to be a lot of inaccurate information out there based on unverified AI queries, so beware.

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