A Pair of Planet-forming Discs in Taurus & Ophiuchus | James Webb Space Telescope
This European Space Agency Webb picture features new stars with the potential for planets. This visual highlights views from the NASA/European Space Agency/Canadian Space Agency James Webb Space Telescope of the protoplanetary discs Tau 042021 (left) and Oph 163131 (right), otherwise known by the catalog numbers 2MASS J04202144+2813491 and 2MASS J16313124-2426281, respectively. Tau 042021 is situated around 450 light-years from Earth in the constellation Taurus, while Oph 163131 lies about 480 light-years away in Ophiuchus.
Protoplanetary discs like these appear around stars that have recently been born. When a clump of gas inside a larger molecular cloud collapses to form a star, unused gas and dust is left orbiting the star in a thick disc. Over time, this dust too collides and collapses, slowly forming planetesimals that can develop into planets. The planetesimals that do not become planets are left behind as asteroids and comets orbiting the star. Furtheremore, gas that is not consumed by this process is blown away by the new star’s radiation over the course of tens of millions of years, ending the protoplanetary disc. This is how our own Solar System formed in the distant past, creating the asteroids, comets, gas giants, and terrestrial planets we know today. By observing other protoplanetary discs at a much earlier age, we can work out how this process may have worked for our own Solar System, and how the planets we see across the galaxy could have formed.
The unique feature these two objects share is that they are oriented with the edge of their discs facing us. This means that the bright light from the young star in the center is mostly blocked, and we see the fine dust that has risen out of the disc as a nebula above and below the disc, lit by reflected light from the star. The distribution of dust in the disc, within it and above or below it, strongly affects where and how planets can form.
Image Description: Two images of protoplanetary discs side-by-side. The left image shows a dark horizontal band covering the star, with broad, colorful, conical outflows above and below it, and a narrow jet pointing directly up and down from the star. The right image shows the star within a yellow dusty disc with scattered dust creating purple lobes above and below the disc. Each is on a black background with several galaxies or stars around it.
These images were created using data from Webb’s NIRCam and MIRI instruments, as part of Webb program#2562 (PI F. Ménard, K. Stapelfeldt). With the broad infrared sensitivity of these two cameras, Webb can track dust grains across the disc. The red, orange and green colors of the discs in these images indicate the sizes of dust grains as well as molecules, such as hydrogen (H2), carbon monoxide (CO) and polycyclic aromatic hydrocarbons (PAHs).
Both images also feature data from the NASA/European Space Agency Hubble Space Telescope that shows visible light, mainly from the central star reflected off the fine, floating dust. The image of Oph 163131 also includes observations from the Atacama Large Millimeter/submillimeter Array (ALMA). Where Hubble and Webb each image tiny dust grains only micrometers across, ALMA sees larger dust grains that are about a milimeter in size, concentrated in the central plane of the disc. This can create the right conditions for the grains to continue to grow and potentially form planets. Indeed, the ALMA data for Oph 163131 shows a gap in the inner disc that may already be evidence of a planet forming and clearing out the dust around it.
Credit: ESA/Webb, NASA & CSA, ESA/Hubble, ALMA (ESO/NAOJ/NRAO), G. DuchĂȘne, M. Villenave
Release Date: April 3, 2026
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