By analyzing new observations from Hubble alongside images captured in 1999, astronomers have successfully tracked the continuing expansion of one of the sky’s most studied supernova remnants, the Crab Nebula. This expansion is fueled by a rapidly spinning pulsar at its core.
This captivating image of the Crab Nebula was taken by the NASA/ESA Hubble Space Telescope in 2024. Image credit: NASA/ESA/STScI/William Blair, JHU/Joseph DePasquale, STScI.
In 1054, astounded Chinese astronomers witnessed a remarkably bright nova, the second brightest object in the night sky after the moon, visible even during the daytime for a remarkable 23 days. Observations of this supernova were also documented by Japanese, Arabian, and Native American astronomers.
Today, the luminous Crab Nebula, also known as Messier 1, M1, NGC 1952, or Taurus A, occupies the position of that brilliant star, situated approximately 6,500 light-years away in the constellation Taurus.
This nebula’s brightness makes it visible even through amateur telescopes, making it a popular object for stargazers.
Initially identified in 1731 by the English physicist and astronomer John Beavis, the Crab Nebula was later rediscovered in 1758 by French astronomer Charles Messier.
The name “Crab Nebula” derives from its resemblance in an 1844 painting by Irish astronomer Lord Rose.
At its center lies the remnant core of the original star, known as the Crab Pulsar (PSR B0531+21).
“We often perceive the sky as a static body,” remarked Dr. William Blair, an astronomer at Johns Hopkins University. “However, the enduring journey of the NASA/ESA Hubble Space Telescope has shown us that the Crab Nebula continues to evolve and expand from the explosion that occurred nearly 1,000 years ago.”
In the latest images, Hubble revealed the nebula’s intricate filament structure, demonstrating substantial outward movement over a 25-year period at an astonishing rate of 5.6 million kilometers per hour (3.4 million miles per hour).
“Hubble possesses the unique longevity and resolution necessary to capture these intricate changes,” the astronomers noted.
To facilitate comparisons with new images, Hubble’s 1999 image of the Crab Nebula has undergone reprocessing.
“The color variations observed in both Hubble images signal changes in the gas’s local temperature, density, and chemical composition.”
“Even after extensive work with Hubble, I’m continually amazed by the detailed structure and improved resolution revealed by Hubble’s Wide Field Camera 3 (WFC3) compared to 25 years ago,” Dr. Blair commented.
“WFC3 was installed in 2009, marking the last time Hubble’s instrument was upgraded by astronauts.”
“The filaments at the edges of the nebula seem to be moving more rapidly than those at the center and appear to be expanding outward instead of stretching over time.”
This phenomenon is attributed to the pulsar’s nature as a pulsar wind nebula, driven by synchrotron radiation generated from interactions between the pulsar’s magnetic field and the surrounding nebula material.
In contrast, other notable supernova remnants typically expand in a manner influenced by shock waves from the initial explosion, which erode the outer shell of gas ejected by the dying star.
The new high-resolution observations from Hubble also offer deeper insights into the Crab Nebula’s three-dimensional structure, challenging to assess from two-dimensional images.
In an intriguing observation, shadows of some filaments are reflected in the haze of synchrotron radiation within the nebula.
Interestingly, some bright filaments in the latest Hubble images do not display shadows, suggesting they are located behind the nebula.
“The true significance of Hubble’s observations of the Crab Nebula is yet to unfold,” the researchers asserted.
“Data from Hubble can be integrated with recent findings from other telescopes observing the Crab Nebula across varying wavelengths of light.”
“NASA/ESA/CSA’s James Webb Space Telescope is set to release infrared light observations of the Crab Nebula in 2024.”
Comparing Hubble’s images with modern multiwavelength observations will provide scientists with a comprehensive understanding of the ongoing aftermath of supernovae, continuing to intrigue astronomers long after new stars first appeared in the sky.
Find more findings published in January 2026. Astrophysical Journal.
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William P. Blair et al. 2026. Revisiting the Crab Nebula using HST/WFC3. APJ 997, 81; doi: 10.3847/1538-4357/ae2adc
Source: www.sci.news
