NIRCam’s view of NGC 6822

This image shows the irregular galaxy NGC 6822, as observed by the Near-InfraRed Camera (NIRCam) mounted on the NASA/ESA/CSA James Webb Space Telescope. NIRCam probes the near-infrared, which in this case makes it suitable for observing the densely packed star field.

Webb’s near-infrared NIRCam image shows the galaxy’s countless stars in incredible detail. Here, the dust and gas that pervade the galaxy are reduced to translucent red wisps, laying the stars bare for astronomical study. The power of Webb’s ice-cold infrared instruments and the incredible resolution of its primary mirror is necessary to examine stars hidden in dusty environments, and the results as shown here are spectacular.

The brightest stars appear in pale blue and cyan colours in this image, colours which are assigned to the shortest wavelengths of light that NIRCam can detect: red and nearest infrared. The amount of light emitted by any star decreases at longer and longer wavelengths, towards the mid-infrared, so the stars that are more faint to NIRCam also appear more warmly coloured here. A bright blue orb to the lower left of the gas is particularly prominent: this is a globular cluster, packed with stars.

A composite image of NGC 6822 featuring data from both NIRCam and Webb’s Mid-InfraRed Instrument (MIRI) was published for the ESA/Webb Picture of the Month series in July 2023.

[Image Description: A huge, dense field completely filled with tiny stars. A few of the star images are a bit larger than the rest, with visible diffraction spikes; two foreground stars are large and bright on the right side. Many small galaxies within various shapes and sizes can be seen hiding behind the stars. In the centre some faint, wispy, dark red gas appears.] or [Image Description: A huge, dense field completely filled with stars. A few of the star images are a bit larger than the rest, with visible diffraction spikes; two foreground stars are bright on the right side. Many galaxies with various shapes and sizes can be seen hiding behind the stars. In the centre some faint, wispy, dark red gas appears.]

Links

• Composite NIRCam and MIRI image of NGC 6822 (July 2023 Picture of the Month)
• MIRI image of NGC 6822 (July 2023 Picture of the Month)
• Science paper (L. Lenkić et al.)
• Science paper (C. Nally et al.)