What does a star actually look like
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What Does a Star Actually Look Like?
Star Images and Human Perception
Entoptic Phenomena and Star Patterns
When people look at bright point sources in darkness, they often perceive star images as entoptic phenomena. These star patterns are believed to be caused by diffraction and ocular aberrations within the human eye. Research has shown that when a small Gaussian spot of light is projected onto the retina, the resulting aerial images display distinctive radiating star patterns. These patterns closely match the subjective star images sketched by observers, supporting the hypothesis that these star images have a purely optical origin1.
Profile of a Star Image
Central Core and Extended Aureole
The profile of a star image, as constructed from various data, consists of a central peak, an exponential drop, and an extended inverse-square aureole. This profile extends out to a radius of six degrees. However, the exact origin of this shape is not well understood2.
Observing Stars Through Telescopes
Point Sources of Light
Most stars are so distant that even the largest telescopes can only resolve them as simple points of light. However, using gravitational lensing, astronomers have been able to magnify and observe features on the surface of distant stars, providing more detailed images than traditional telescopic observations3.
Stars in Magnetic Grand Minima
Physical and Magnetic Properties
Stars in a Maunder-like magnetic minimum exhibit unique physical and magnetic activity properties. New X-ray observations of such stars have been compared with the Sun and other low-activity stars to understand their characteristics better. These stars are typically less active and have different observable features compared to more magnetically active stars4.
Collapsing Stars
Gravitational Collapse and Visibility
The optical image of a star undergoing gravitational collapse changes over time. As the star collapses, it emits radiation that follows Lambert's cosine law. The spectral photon flux and spectral radiant flux of the star can be calculated for both monochromatic and blackbody radiation. During the collapse, the redshift factor remains finite, and the star gradually becomes invisible due to the decay of the photon flux. This phenomenon highlights the dynamic nature of star images during different stages of stellar evolution5.
Conclusion
In summary, the appearance of a star can vary significantly depending on the context of observation. From the entoptic phenomena perceived by the human eye to the detailed profiles constructed by astronomers, and the dynamic changes observed during gravitational collapse, stars present a complex and multifaceted image. Understanding these various aspects helps us appreciate the intricate beauty and complexity of these celestial objects.
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Most relevant research papers on this topic
Shape of stars and optical quality of the human eye.
Star images in darkness are primarily optical, with diffraction and ocular aberrations playing a role in their formation.
THE PROFILE OF A STAR IMAGE
The profile of a star image has a central core, exponential drop, and extended inverse-square aureole, with its origin well understood but its shape remains unresolved.
Highly CitedStars in magnetic grand minima: where are they and what are they like?
Stars in magnetic grand minima have low physical and magnetic activity, and can be found using new X-ray observations.
How does a collapsing star look?
A collapsing star gradually becomes invisible due to decay of photon flux, with the redshift factor remaining finite and the star becoming gradually invisible due to decay of photon flux.
Direct evidence of star structure from nuclear magnetic resonance spectroscopy
This study provides direct evidence of star structure using nuclear magnetic resonance spectroscopy, revealing the key point of the star, the silicon atom, in polybutadiene and polyisoprene stars with up to four arms.
A dusty torus around the luminous young star LkHα101
The inner accretion disk of LkH101 is face-on, with a central gap and hot inner edge, suggesting that the inner edge is likely determined by sublimation of dust grains by direct stellar radiation.
Highly CitedTWELVE ADDITIONAL "VEGA-LIKE" STARS.
Additional Vega-like stars have been identified, suggesting the presence of circumstellar disks viewed edge-on.
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