Wednesday, January 27, 2021

Brown Dwarf Animation & Xallarap Effect Animation - NASA Video

 

Illustration depicting a brown dwarf, which range from about 4,000 to 25,000 times Earth’s mass. They’re too heavy to be characterized as planets, but not quite massive enough to undergo nuclear fusion in their cores like stars. Read more: https://www.nasa.gov/feature/goddard/...
Video credit: NASA's Goddard Space Flight Center Scott Wiessinger (USRA): Animator Scott Wiessinger (USRA): Producer Ashley Balzer (ADNET): Science Writer Claire Andreoli (NASA/GSFC): Public Affairs Officer


Animation depicting the xallarap effect. As a planet moves around its host star, it exerts a tiny gravitational tug that shifts the star’s position a bit. This can pull the distant star closer and farther from a perfect alignment. Since the nearer star acts as a natural lens, it’s like the distant star’s light will be pulled slightly in and out of focus by the orbiting planet. By picking out little shudders in the starlight, astronomers will be able to infer the presence of planets. Xallarap is parallax spelled backward. Parallax relies on motion of the observer – Earth moving around the Sun – to produce a change in the alignment between the distant source star, the closer lens star and the observer. Xallarap works the opposite way, modifying the alignment due to the motion of the source. While microlensing is generally best suited to finding worlds farther from their star than Venus is from the Sun, the xallarap effect works best with very massive planets in small orbits, since they make their host star move the most. Revealing more distant planets will also allow us to probe a different population of worlds. Read more: https://www.nasa.gov/feature/goddard/...
Video credit: NASA's Goddard Space Flight Center Scott Wiessinger (USRA): Animator Scott Wiessinger (USRA): Producer Ashley Balzer (ADNET): Science Writer Claire Andreoli (NASA/GSFC): Public Affairs Officer Samson Johnson (Ohio State University): Scientist Shota Miyazaki (Osaka University): Scientist

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