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Webb and Hubble’s Views of Spiral Galaxy NGC 1365

Webb’s image of galaxy NGC 1365 shows a central region that looks like an angled, smashed oval that is a mix of bright orange shades that emanate a blue glow. The galaxy’s bar extends horizontally from the oval. It is crossed by messy dust filaments that curve slightly, forming a backward S shape. Fainter filaments appear below and above the core.

Barred spiral galaxy, NGC 1365, is split diagonally in this image: The James Webb Space Telescope’s observations appear on bottom right, and the Hubble Space Telescope’s at top left. Webb and Hubble’s images show a striking contrast, an inverse of darkness and light. Why? Webb’s observations combine near- and mid-infrared light and Hubble’s showcase visible and ultraviolet light. Dust absorbs ultraviolet and visible light, and then re-emits it in the infrared. In Webb's images, we see dust glowing in infrared light. In Hubble’s images, dark regions are where starlight is absorbed by dust.

The individual Webb and Hubble images are available for download using the links on the left side of this page.

Color Decoder

Gas and Dust

In Webb’s high-resolution infrared images, the gas and dust stand out in stark shades of orange and red, and show finer spiral shapes with the appearance of jagged edges, though these areas are still diffuse.

In Hubble’s images, the gas and dust show up as hazy dark brown lanes, following the same spiral shapes. Its images are about the same resolution as Webb’s, but the gas and dust obscure a lot of the smaller-scale star formation.

Bright Central Spikes

Bright red diffraction spikes at a galaxy’s core in a Webb image can be a “calling card” of an active supermassive black hole, as seen in galaxy NGC 7496. Not all oversized diffraction spikes at galaxies’ cores are caused by black holes, though. Sometimes, they appear when a slew of very bright, centrally located star clusters are in the central region of Webb’s image.

In Hubble’s images, the galaxies’ cores are not as bright so these spikes are absent. Diffraction spikes only appear when the source is extremely bright and compact.

Older Stars

Sometimes, the central region in Webb’s image has a blue glow. This is a marker of high concentrations of older stars. Webb’s infrared observations allow us to see through the gas and dust to identify these older stars. The light these old stars emit are some of the shortest infrared wavelengths in Webb’s images, which is why they are assigned blue. (Read more about how color is precisely applied to Webb’s images.)

In comparison, the cores of Hubble’s image may appear yellower, washing the central region in a soft glow and fully obscuring individual points of light. Hazy brown dust lanes may also cover part of this area. In Hubble’s images, older stars are emitting some of the longest wavelengths of visible light Hubble captures, which is why the color assignments are different. (Compare the wavelengths of light Hubble and Webb observe.)

Younger Stars

In Webb’s image, the newly fully formed stars also appear blue along the galaxies’ spiral arms. Those blue stars have blown away the gas and dust that immediately surrounded them. The farther away they are from the core, the more likely stars are to be younger. Orange stars, likely seen in groups in these images, are even younger: They are still encased in their cocoons of gas and dust, allowing them to continue forming.

In Hubble’s images, younger stars pop out in blue and purple – and appear almost everywhere. In contrast, the older stars near the center of the galaxy appear yellowish.

Star-Forming Regions

Look for knots of bright red and orange in Webb’s image. These are especially easy to identify toward the outer edges of the galaxy’s spiral arms. These are regions of star formation, and mid-infrared light highlights the gas and dust that are a huge part of the mix, since they are primary ingredients for stars that are actively forming.

In Hubble’s images, star-forming regions are clusters of bright blue and purple, or sometimes red and pink as hot stars energize nearby hydrogen gas.

Background Galaxies

Webb’s image includes distant galaxies that are located well behind the tightly cropped foreground galaxy. Look for bright blue and pink disks, some seen edge-on, like a plate with a central sphere. Redder galaxies are more distant.

In Hubble’s view, distant galaxies are often light orange if they are slightly closer. Like in Webb's image, those that are deeper red are also more distant.

Galaxy NGC 1365 was observed as part of the Physics at High Angular resolution in Nearby GalaxieS (PHANGS) program, a large project that includes observations from several space- and ground-based telescopes of many galaxies to help researchers study all phases of the star formation cycle, from the formation of stars within dusty gas clouds to the energy released in the process that creates the intricate structures revealed by Webb’s new images.

NGC 1365 is 56 million light-years away in the constellation Fornax.

About the Object

  • R.A. Position
    R.A. PositionRight ascension – analogous to longitude – is one component of an object's position.
    03:33:36.46
  • Dec. Position
    Dec. PositionDeclination – analogous to latitude – is one component of an object's position.
    -36:08:26.37
  • Constellation
    ConstellationOne of 88 recognized regions of the celestial sphere in which the object appears.
    Fornax
  • Distance
    DistanceThe physical distance from Earth to the astronomical object. Distances within our solar system are usually measured in Astronomical Units (AU). Distances between stars are usually measured in light-years. Interstellar distances can also be measured in parsecs.
    About 56 million light-years away

About the Data

  • Data Description
    Data DescriptionProposal: A description of the observations, their scientific justification, and the links to the data available in the science archive.
    Science Team: The astronomers who planned the observations and analyzed the data. "PI" refers to the Principal Investigator.

    The Webb image was created with data from proposal: 2107 (J. Lee). Image Processing: Joseph DePasquale (STScI).

  • Instrument
    InstrumentThe science instrument used to produce the data.
    Webb> NIRCam, MIRI Hubble> WFC3/UVIS
  • Filters
    FiltersThe camera filters that were used in the science observations.
    Webb> F300M, F335M, F360M, F770W, F1000W, F1130W, F2100W Hubble> F275W, F336W, F438W, F555W, F814W
  • Object Name
    Object NameA name or catalog number that astronomers use to identify an astronomical object.
    NGC 1365
  • Object Description
    Object DescriptionThe type of astronomical object.
    Barred spiral galaxy
  • Release Date
    January 29, 2024
  • Science Release
    NASA’s Webb Depicts Staggering Structure in 19 Nearby Spiral Galaxies
  • Credit
    Image: NASA, ESA, CSA, STScI, PHANGS Team, Janice Lee (STScI), Thomas Williams (Oxford)

Downloads

  • Webb Full Res (For Print), 2617 × 2085
    tif (11.54 MB)
  • Webb Full Res (For Display), 2617 × 2085
    png (8.57 MB)
  • Webb, 2000 × 1593
    png (5.12 MB)
  • Hubble Full Res (For Print), 2617 × 2085
    tif (8.59 MB)
  • Hubble Full Res (For Display), 2617 × 2085
    png (6.69 MB)
  • Hubble, 2000 × 1593
    png (4.03 MB)
  • Webb + Hubble (For Print), 2617 × 2085
    tif (10.81 MB)
  • Webb + Hubble (For Display), 2617 × 2085
    png (8.19 MB)
  • Webb + Hubble, 2000 × 1593
    png (5.09 MB)
Webb’s image of galaxy NGC 1365 shows a central region that looks like an angled, smashed oval that is a mix of bright orange shades that emanate a blue glow. The galaxy’s bar extends horizontally from the oval. It is crossed by messy dust filaments that curve slightly, forming a backward S shape. Fainter filaments appear below and above the core.
Color Info
Color InfoA brief description of the methods used to convert telescope data into the color image being presented.

Webb Image: This image is a composite of separate exposures acquired by the James Webb Space Telescope using the NIRCam and MIRI instruments. Several filters were used to sample specific wavelength ranges. The color results from assigning different hues (colors) to each monochromatic (grayscale) image associated with an individual filter. In this case, the assigned colors are:   Red = F2100W + F1130W + F1000W + F770WGreen = F770W + F360MBlue = F335M + F300M Hubble Image: This image is a composite of separate exposures acquired by the Hubble Space Telescope using the WFC3/UVIS instrument. Several filters were used to sample specific wavelength ranges. The color results from assigning different hues (colors) to each monochromatic (grayscale) image associated with an individual filter. In this case, the assigned colors are:   Red= F814W Green = F555W Blue = F438W Blue = F336W Purple = F275W

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Details

Last Updated
Aug 28, 2025
Contact
Media

Laura Betz
NASA’s Goddard Space Flight Center
Greenbelt, Maryland
laura.e.betz@nasa.gov

Image Credit

NASA, ESA, CSA, STScI, PHANGS Team, Janice Lee (STScI), Thomas Williams (Oxford)