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Sagittarius B2 (MIRI Image)

Cosmic clouds of pink and purple, some with bright centers, are surrounded by dark areas that appear like black space dotted with bright blue stars. A group of small clouds to the right is more red than any other area of the image.

Webb’s MIRI (Mid-Infrared Instrument) shows the Sagittarius B2 (Sgr B2) region in mid-infrared light, with warm dust glowing brightly. To the right is one clump of clouds that captured astronomers’ attention. It is redder than the rest of the clouds in the image and corresponds to an area that other telescopes have shown to be one of the most molecularly rich regions known. Additional analysis of this intriguing region could yield important insights into why Sgr B2 is so much more productive in making stars than the rest of the galactic center.

Only the brightest stars in this region emit mid-infrared light that can be picked up by Webb’s MIRI instrument, which is why this image has so many fewer stars than that captured by Webb’s NIRCam (Near-Infrared Camera). The darkest areas of the image are not empty space but areas where cosmic dust and gas are so dense that light cannot penetrate them to reach the telescope.

About the Object

  • R.A. Position
    R.A. PositionRight ascension – analogous to longitude – is one component of an object's position.
    17:47:19.98
  • Dec. Position
    Dec. PositionDeclination – analogous to latitude – is one component of an object's position.
    -28:23:50.73
  • Constellation
    ConstellationOne of 88 recognized regions of the celestial sphere in which the object appears.
    Sagittarius
  • 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 26,000 light-years
  • Dimensions
    DimensionsThe physical size of the object or the apparent angle it subtends on the sky.
    Image is about 4.6 arcminutes across (35 light-years)

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.

    This image was created with Webb data from proposal: 5365 (A. Ginsburg). 

  • Instrument
    InstrumentThe science instrument used to produce the data.
    MIRI
  • Exposure Dates
    Exposure DatesThe date(s) that the telescope made its observations and the total exposure time.
    15 Sept. 2024
  • Filters
    FiltersThe camera filters that were used in the science observations.
    F770W, F1280W, F1550W
  • Object Name
    Object NameA name or catalog number that astronomers use to identify an astronomical object.
    Sagittarius B2, Sgr B2
  • Object Description
    Object DescriptionThe type of astronomical object.
    Giant molecular cloud at the center of the Milky Way
  • Release Date
    September 24, 2025
  • Science Release
    NASA’s Webb Explores Largest Star-Forming Cloud in Milky Way
    Read the release
  • Credit
    Image: NASA, ESA, CSA, STScI, Adam Ginsburg (University of Florida), Nazar Budaiev (University of Florida), Taehwa Yoo (University of Florida); Image Processing: Alyssa Pagan (STScI)

Downloads

  • Full Res (For Print), 2487 × 1095
    tif (4.27 MB)
  • Full Res (For Display), 2487 × 1095
    png (3.47 MB)
  • 2487 × 1095
    jpg (1.72 MB)
Cosmic clouds of pink and purple, some with bright centers, are surrounded by dark areas that appear like black space dotted with bright blue stars. A group of small clouds to the right is more red than any other area of the image.
Color Info
Color InfoA brief description of the methods used to convert telescope data into the color image being presented.

This image is a composite of separate exposures acquired by the James Webb Space Telescope using the MIRI instrument. Several filters were used to sample wide 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:   Blue= F770W, Green= F1280W, Red= F1550W

Compass and Scale
Compass and ScaleAn astronomical image with a scale that shows how large an object is on the sky, a compass that shows how the object is oriented on the sky, and the filters with which the image was made.

Related Images & Videos

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Sagittarius B2 (NIRCam Image)

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Sagittarius B2 (NIRCam Compass Image)

This image of the Sagittarius B2 (Sgr B2) molecular cloud, captured by the NIRCam (Near-Infrared Camera) instrument on NASA’s James Webb Space Telescope includes compass arrows, scale bar, and color key for reference.

Cosmic clouds of pink and purple, some with bright centers, are surrounded by dark areas that appear like black space dotted with bright blue stars. Compass arrows, scale bar, and color key are included for reference.

Sagittarius B2 (MIRI Compass Image)

This image of the Sagittarius B2 (Sgr B2) molecular cloud, captured by MIRI (Mid-Infrared Instrument) on NASA’s James Webb Space Telescope includes compass arrows, scale bar, and color key for reference.

A wide view of a region of space filled with stars and clumps of orange clouds.

Sagittarius B2 NIRCam to MIRI Fade

See what different wavelengths of infrared light reveal and conceal. Near-infrared light, which is nearest to visible red, comes from some gas and an abundance of colorful stars. The longer wavelengths of mid-infrared light are emitted by warm dust and only the brightest stars....

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Details

Last Updated
Sep 24, 2025
Location
NASA Goddard Space Flight Center
Contact
Media

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

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