Presenter Information

Joseph KellyFollow

Presentation Type

Poster

Faculty Mentor’s Full Name

Angela Des Jardins

Faculty Mentor’s Department

Physics and Astronomy

Abstract

The outermost layer of the sun, the chromosphere, cannot normally be seen due to the overwhelming brightness of the photosphere, the layer beneath it. However, in certain wavelengths of light, the chromosphere outshines the photosphere, meaning it can be seen when these wavelengths are selected for. One such wavelength of light is in the near infrared spectrum, centered around 670 nm. When the infrared filters are removed from regular cameras, they are able to see far enough into the infrared spectrum to detect light of these wavelengths. Unfortunately, the atmosphere absorbs most incoming radiation in the near infrared spectrum, meaning that one cannot measure light coming from the chromosphere from the ground. Instead, I affixed two cameras to a balloon, which was flown to 60,000 feet in elevation, high enough that the atmosphere no longer absorbed significant amounts of near infrared light. One camera took images in the visible spectrum, while the other filter out all light except that in the near infrared spectrum. Consequently, one camera took “normal” pictures of the sun while the other took pictures of the chromosphere of the sun. By comparing the images, the most apparent difference between them was in a phenomenon known as “limb darkening,” which is the effect where the edges of a star look darker than the center. This is caused by the light seen emanating from the center of a star being emitted from deeper within the star, where it is hotter and consequently brighter. While the visible-spectrum images displayed this effect in full, the near infrared images did not, as they were only viewing one layer of the sun.

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Physical Sciences

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Apr 17th, 3:00 PM Apr 17th, 4:00 PM

Viewing the Chromosphere of the Sun in the Near Infrared Spectrum

UC South Ballroom

The outermost layer of the sun, the chromosphere, cannot normally be seen due to the overwhelming brightness of the photosphere, the layer beneath it. However, in certain wavelengths of light, the chromosphere outshines the photosphere, meaning it can be seen when these wavelengths are selected for. One such wavelength of light is in the near infrared spectrum, centered around 670 nm. When the infrared filters are removed from regular cameras, they are able to see far enough into the infrared spectrum to detect light of these wavelengths. Unfortunately, the atmosphere absorbs most incoming radiation in the near infrared spectrum, meaning that one cannot measure light coming from the chromosphere from the ground. Instead, I affixed two cameras to a balloon, which was flown to 60,000 feet in elevation, high enough that the atmosphere no longer absorbed significant amounts of near infrared light. One camera took images in the visible spectrum, while the other filter out all light except that in the near infrared spectrum. Consequently, one camera took “normal” pictures of the sun while the other took pictures of the chromosphere of the sun. By comparing the images, the most apparent difference between them was in a phenomenon known as “limb darkening,” which is the effect where the edges of a star look darker than the center. This is caused by the light seen emanating from the center of a star being emitted from deeper within the star, where it is hotter and consequently brighter. While the visible-spectrum images displayed this effect in full, the near infrared images did not, as they were only viewing one layer of the sun.