The Vela Pulsar as a Spirograph

By Nancy Atkinson - February 27, 2013 at 4:52 PM UTC | uncategorized
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I loved my Spirograph when I was young, and obviously Eric Charles, a physicist with the Fermi Gamma-ray Space Telescope team did too. Charles has taken data from Fermi's Large Area Telescope and turned it into a mesmerizing movie of the Vela Pulsar. It actually is a reflection of the complex motion of the spacecraft as it stared at the pulsar.

The video shows the intricate pattern traced by the Fermi Gamma-ray Space Telescope's view of the Vela Pulsar over the spacecraft's 51 months in orbit.

Fermi orbits our planet every 95 minutes, building up increasingly deeper views of the universe with every circuit. Its wide-eyed Large Area Telescope (LAT) sweeps across the entire sky every three hours, capturing the highest-energy form of light -- gamma rays -- from sources across the universe. The Fermi telescope has given us our best view yet of the bizarre world of the high energy Universe, which include supermassive black holes billions of light-years away to intriguing objects in our own galaxy, such as X-ray binaries, supernova remnants and pulsars.

Francis Reddy from the Goddard Spaceflight Center describes the movie:

The Vela pulsar outlines a fascinating pattern in this movie showing 51 months of position and exposure data from Fermi's Large Area Telescope (LAT). The pattern reflects numerous motions of the spacecraft, including its orbit around Earth, the precession of its orbital plane, the manner in which the LAT nods north and south on alternate orbits, and more. The movie renders Vela's position in a fisheye perspective, where the middle of the pattern corresponds to the central and most sensitive portion of the LAT's field of view. The edge of the pattern is 90 degrees away from the center and well beyond what scientists regard as the effective limit of the LAT's vision. Better knowledge of how the LAT's sensitivity changes across its field of view helps Fermi scientists better understand both the instrument and the data it returns.

The pulsar traces out a loopy, hypnotic pattern reminiscent of art produced by the colored pens and spinning gears of a Spirograph, a children's toy that produces geometric patterns.

The Vela pulsar spins 11 times a second and is the brightest persistent source of gamma rays the LAT sees. While gamma-ray bursts and flares from distant black holes occasionally outshine the pulsar, the Vela pulsar is like a persistant beacon, much like the light from a lighthouse.

Find out more about this movie and the Fermi Telescope

here.

Nancy Atkinson

Nancy Atkinson

Nancy Atkinson is a space journalist and author with a passion for telling the stories of people involved in space exploration and astronomy. She is currently retired from daily writing, but worked at Universe Today for 20 years as a writer and editor. She also contributed articles to The Planetary Society, Ad Astra (National Space Society), New Scientist and many other online outlets.

Her 2019 book, "Eight Years to the Moon: The History of the Apollo Missions,” shares the untold stories of engineers and scientists who worked behind the scenes to make the Apollo program so successful, despite the daunting odds against it. Her first book “Incredible Stories From Space: A Behind-the-Scenes Look at the Missions Changing Our View of the Cosmos” (2016) tells the stories of 37 scientists and engineers that work on several current NASA robotic missions to explore the solar system and beyond.

Nancy is also a NASA/JPL Solar System Ambassador, and through this program, she has the opportunity to share her passion of space and astronomy with children and adults through presentations and programs. Nancy's personal website is nancyatkinson.com