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Wolf-Rayet Apep (MIRI Image)

Four dust shells in Wolf-Rayet Apep expand away from three central stars that appear as a single pinpoint of light. The shells are curved, and the interior shell looks like a backward lowercase e shape.

NASA’s James Webb Space Telescope’s mid-infrared image shows four coiled shells of dust around a pair of Wolf-Rayet stars known as Apep for the first time. Previous observations by other telescopes showed only one. (Watch a 3D visualization of the system.)

Webb’s data, combined with observations from the European Southern Observatory’s Very Large Telescope (VLT) in Chile, confirmed that the two Wolf-Rayet stars sail past one another approximately every 190 years. Over each orbit, they make a close pass for 25 years, producing and spewing amorphous carbon dust.

Webb’s new data also confirmed that there are three stars gravitationally bound to one another in this system. Holes are “sliced” into these shells by the third star, a massive supergiant.

About the Object

  • R.A. Position
    R.A. PositionRight ascension – analogous to longitude – is one component of an object's position.
    16:00:50.5
  • Dec. Position
    Dec. PositionDeclination – analogous to latitude – is one component of an object's position.
    -51:42:45.0
  • Constellation
    ConstellationOne of 88 recognized regions of the celestial sphere in which the object appears.
    Norma
  • 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.
    8,000 light-years
  • Dimensions
    DimensionsThe physical size of the object or the apparent angle it subtends on the sky.
    Image is about 1.9 arcminutes across (4 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: 5842 (Y. Han). Image processing: Alyssa Pagan (STScI).

  • 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.
    24 July 2024
  • Filters
    FiltersThe camera filters that were used in the science observations.
    F770W, F1500W, F2550W
  • Object Name
    Object NameA name or catalog number that astronomers use to identify an astronomical object.
    Apep, 2XMM J160050.7–514245
  • Object Description
    Object DescriptionThe type of astronomical object.
    Wolf-Rayet Binary
  • Release Date
    November 19, 2025
  • Science Release
    Webb First to Show 4 Dust Shells ‘Spiraling’ Apep, Limits Long Orbit
    Read the release
  • Credit
    Image: NASA, ESA, CSA, STScI; Science: Yinuo Han (Caltech), Ryan White (Macquarie University); Image Processing: Alyssa Pagan (STScI)

Downloads

  • Full Res (For Print), 1021 × 773
    tif (752.04 KB)
  • Full Res (For Display), 1021 × 773
    png (668.25 KB)
  • 1021 × 773
    jpg (294.58 KB)
Four dust shells in Wolf-Rayet Apep expand away from three central stars that appear as a single pinpoint of light. The shells are curved, and the interior shell looks like a backward lowercase e shape.
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: F770W+F1500W, Red: F2550W  

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

Image titled u201cJames Webb Space Telescope; Apep, WR 70-16,u201d with compass arrows and color key.

Wolf-Rayet Apep (MIRI Compass Image)

This image of the Wolf-Rayet binary Apep, captured by the James Webb Space Telescope’s MIRI (Mid-Infrared Instrument), shows compass arrows, scale bar, and color key for reference.

At top left is the label simulation. Three semi-transparent orange shells are set against a black background.

Wolf-Rayet Apep Visualization

This scientific visualization models what three of the four dust shells sent out by two Wolf-Rayet stars in the Apep system look like in 3D based on mid-infrared observations from NASA’s James Webb Space Telescope. Apep is made up of two Wolf-Rayet binary stars that are orb...

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Details

Last Updated
Nov 18, 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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