![Hubble and Webb Observations of Vega Circumstellar Debris Disk. [left]-A Hubble Space Telescope false-color view of a 100-billion-mile-wide disk of dust around the summer star Vega. Hubble detects reflected light from dust that is the size of smoke particles largely in a halo on the periphery of the disk. The disk is very smooth, with no evidence of embedded large planets. The black spot at the center blocks out the bright glow of the hot young star. [right]-The James Webb Space Telescope resolves the glow of warm dust in a disk halo, at 23 billion miles out. The outer disk (analogous to the solar system’s Kuiper Belt) extends from 7 billion miles to 15 billion miles. The inner disk extends from the inner edge of the outer disk down to close proximity to the star. There is a notable dip in surface brightness of the inner disk from approximately 3.7 to 7.2 billion miles. The black spot at the center is due to lack of data from saturation.](https://scienceblog.com/wp-content/uploads/2024/11/vega-disk.jpeg)
Summary: Using NASA’s Hubble and James Webb space telescopes, astronomers have conducted an unprecedented study of the debris disk surrounding the star Vega. The observations reveal a surprisingly smooth disk extending nearly 100 billion miles, challenging our understanding of planetary system formation and evolution.
Journal: The Astrophysical Journal, November 2024
Reading time: 4 minutes
A Surprisingly Clean Cosmic Disk
Vega, one of the brightest stars in our northern sky, has been hiding a cosmic mystery. New observations from NASA’s most powerful space telescopes have revealed something unexpected about the vast disk of debris surrounding this brilliant star.
“Between the Hubble and Webb telescopes, you get this very clear view of Vega. It’s a mysterious system because it’s unlike other circumstellar disks we’ve looked at,” said Andras Gáspár of the University of Arizona. “The Vega disk is smooth, ridiculously smooth.”
Breaking Scientific Expectations
The discovery is causing scientists to rethink their theories about planetary systems. As Kate Su, lead author of the Webb findings, explains: “It’s making us rethink the range and variety among exoplanet systems.”
The observations show no evidence of large planets carving paths through the disk. This stands in stark contrast to similar nearby stars like Fomalhaut, which shows clear signs of planetary influence in its debris system.
A Historical Perspective
Vega holds a special place in astronomical history. It was the first star to offer evidence of orbiting material that could form planets, though this wasn’t discovered until 1984. The idea was first proposed by Immanuel Kant in 1775, but it took modern technology to confirm his hypothesis.
“The Hubble and Webb observations together provide so much more detail that they are telling us something completely new about the Vega system that nobody knew before,” said team member George Rieke.
Technical Terms Glossary
Circumstellar Disk: A ring of dust and debris that orbits around a star.
Debris Disk: A disk of dust created by collisions between asteroids and comets orbiting a star.
Astronomical Unit (AU): A unit of measurement equal to the distance between Earth and the Sun.
Zodiacal Light: The glow created by sunlight reflecting off dust in our solar system.
Test Your Knowledge
1. How wide is Vega’s debris disk?
Answer: Nearly 100 billion miles in diameter
2. What makes Vega’s disk unusual compared to other star systems?
Answer: It’s extremely smooth with no obvious signs of planets
3. When was the first evidence of material orbiting Vega discovered?
Answer: 1984
4. How much brighter is Vega than our Sun?
Answer: 40 times brighter
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