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Saguaro in GOODS-North Field (NIRCam)

A rectangular image with thousands of galaxies of various shapes and colors on the black background of space. Some are noticeably spirals, either face-on or edge-on, while others are blobby ellipticals. Many are too small to discern any structure. One prominent foreground star at top center features Webb’s signature 8-point diffraction spikes. At upper right, a box shows a zoomed in portion of the image. The pullout features a spiral galaxy labeled “WISEA J123635.56+621424.2.” The galaxy has a bright yellow center and faint brown arms speckled with regions of blue that appear to wind clockwise around the galaxy’s core.

First discovered by NASA’s James Webb Space Telescope in 2022, little red dots (LRDs) have continued to perplex scientists. Although they appear abundant at high redshifts early in the universe, they rapidly decrease in number at lower redshifts.

To explore why LRDs decrease in number as the universe ages, researchers examined lower-redshift spiral galaxy WISEA J123635.56+621424.2. Nicknamed the “Saguaro” for its prominent arms, like the cactus native to the Sonoran Desert in the Southwestern United States, this redshift 2 galaxy contains an LRD-like center.

About the Object

  • R.A. Position
    R.A. PositionRight ascension – analogous to longitude – is one component of an object's position.
    12:36:35.56
  • Dec. Position
    Dec. PositionDeclination – analogous to latitude – is one component of an object's position.
    +62:14:24.3
  • Constellation
    ConstellationOne of 88 recognized regions of the celestial sphere in which the object appears.
    Ursa Major
  • Dimensions
    DimensionsThe physical size of the object or the apparent angle it subtends on the sky.
    This image is about 8 arcminutes across.

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: 1181 (D. Eisenstein)

  • Instrument
    InstrumentThe science instrument used to produce the data.
    NIRCam
  • Exposure Dates
    Exposure DatesThe date(s) that the telescope made its observations and the total exposure time.
    04-05 February 2023
  • Filters
    FiltersThe camera filters that were used in the science observations.
    F090W, F115W, F150W, F200W, F277W, F335M, F356W, F410M, F444W
  • Object Name
    Object NameA name or catalog number that astronomers use to identify an astronomical object.
    Saguaro, WISEA J123635.56+621424.2
  • Object Description
    Object DescriptionThe type of astronomical object.
    z=2 distant, IR-Bright, galaxy
  • Release Date
    July 29, 2026
  • Science Release
    NASA Webb Explores Family Tree of Newly Discovered Distant Objects
    Read the release
  • Credit
    Image: NASA, ESA, CSA, STScI, Pierluigi Rinaldi (Steward Observatory); Image Processing: Alyssa Pagan (STScI)

Downloads

  • Full Res (For Print), 16191 × 7844
    tif (199.98 MB)
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  • 2000 × 969
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A rectangular image with thousands of galaxies of various shapes and colors on the black background of space. Some are noticeably spirals, either face-on or edge-on, while others are blobby ellipticals. Many are too small to discern any structure. One prominent foreground star at top center features Webb’s signature 8-point diffraction spikes. At upper right, a box shows a zoomed in portion of the image. The pullout features a spiral galaxy labeled “WISEA J123635.56+621424.2.” The galaxy has a bright yellow center and faint brown arms speckled with regions of blue that appear to wind clockwise around the galaxy’s core.
Color Info
Color InfoA brief description of the methods used to convert telescope data into the color image being presented.

These images are a composite of separate exposures acquired by the James Webb Space Telescope using the NIRCam 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:  Blue: F090W+F115W+F150W, Green: F200W+F277W+F335M, Red: F356W+F410M+F444W

Related Images & Videos

Three squares angled slightly toward the left against a black background. The largest square is at left with a large hazy spiral galaxy in its center. The galaxy has a bright yellow center and faint brown arms speckled with regions of blue that appear to wind clockwise around the galaxyu2019s core. Text near the bottom of the square reads: Real, 10.4 billion years ago, z = 2. A set of two smaller squares appear near the top right. Each small square shows a small hazy red dot in the center against a black background, with the little red dot in the small left square a bit brighter than the dot in the right square. The small square on the left is labeled: Simulated, 13 billion years ago, z = 7. The small square on the right is labeled: Real. A set of lines connects the large square with the spiral galaxy and the simulated little red dot in the small square.

Little Red Dot at Redshift 2: Real and Simulated Graphic

Scientists synthetically shifted the Saguaro, a lower-redshift spiral galaxy, to a higher redshift to find out how it would appear if it was in the early universe. Its compact red appearance suggests that little red dots are a phase of highly active supermassive black holes.

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Details

Last Updated
Jul 29, 2026
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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