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Galaxy Cluster MACS J1423 (NIRCam Compass Image)

A graphic labeled “James Webb Space Telescope; MACS J1423.8+2404.” A rectangular image shows thousands of galaxies of various shapes and colors on the black background of space.

This image of galaxy cluster MACS J1423, captured by the James Webb Space Telescope’s NIRCam (Near-Infrared Camera), shows compass arrows, scale bar, and color key for reference.

The north and east compass arrows show the orientation of the image on the sky.

The scale bar is labeled in arcseconds, which is a measure of angular distance on the sky. One arcsecond is equal an angular measurement of 1/3600 of one degree. There are 60 arcminutes in a degree and 60 arcseconds in an arcminute. (The full Moon has an angular diameter of about 30 arcminutes.) The actual size of an object that covers one arcsecond on the sky depends on its distance from the telescope.

This image shows invisible near-infrared wavelengths of light that have been translated into visible-light colors. The color key shows which NIRCam filters were used when collecting the light. The color of each filter name is the visible light color used to represent the infrared light that passes through that filter.

About the Object

  • R.A. Position
    R.A. PositionRight ascension – analogous to longitude – is one component of an object's position.
    14:23:47.79
  • Dec. Position
    Dec. PositionDeclination – analogous to latitude – is one component of an object's position.
    24:05:4.64
  • Constellation
    ConstellationOne of 88 recognized regions of the celestial sphere in which the object appears.
    Boötes
  • 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.
    Galaxy cluster is 5 billion light-years away
  • Dimensions
    DimensionsThe physical size of the object or the apparent angle it subtends on the sky.
    Image is about 2.3 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 from Webb data from proposal: 1208 (C. J. Willott). Image processing: Alyssa Pagan (STScI).

  • 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.
    26 Feb 2023
  • Filters
    FiltersThe camera filters that were used in the science observations.
    F115W, F150W, F200W, F277W, F356W, F444W
  • Object Name
    Object NameA name or catalog number that astronomers use to identify an astronomical object.
    MACS J1423.8+2404
  • Object Description
    Object DescriptionThe type of astronomical object.
    Galaxy cluster
  • Release Date
    December 11, 2024
  • Science Release
    Found: First Actively Forming Galaxy as Lightweight as Young Milky Way
    Read the release
  • Credit
    Image: NASA, ESA, CSA, STScI, Christopher Willott (NRC-Canada), Lamiya Mowla (Wellesley College), Kartheik Iyer (Columbia)

Downloads

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A graphic labeled “James Webb Space Telescope; MACS J1423.8+2404.” A rectangular image shows thousands of galaxies of various shapes and colors on the black background of space.
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 NIRCam 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: F115W + F150W, Green: F200W + F277W, Red: F356W + F444W

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.

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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, Christopher Willott (NRC-Canada), Lamiya Mowla (Wellesley College), Kartheik Iyer (Columbia)

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