Hubble turns 36 with a dazzling Trifid Nebula portrait

The colors in Hubble’s visible light image of this shimmering region of star formation are reminiscent of an underwater scene filled with fine-grained sediment flowing from the depths of the ocean.

Many massive stars, which lie outside this field of view, have shaped the region for at least 300,000 years. Their powerful ultraviolet winds continue to blow up a giant bubble, a small part of which is shown here, which pushes and compresses the cloud’s gas and dust, generating new waves of star formation.

This is not the first time Hubble has seen this scene. The telescope observed Trifid in 1997 and now, 29 years later, it has taken advantage of its nearly full operational lifetime to show changes in the nebula on human time scales. Why see the same place again? In addition to observing changes over time, Hubble is also equipped with an improved camera with a wider field of view and greater sensitivity that was installed during the fourth servicing mission.

Star formation in the ‘Cosmic Sea Lemon’

Hubble’s view of the Trifid Nebula (also known as Messier 20 or M20) focuses on the ‘head’ and undulating ‘body’ of the rust-colored cloud of gas and dust that resembles a marine sea lemon or sea slug, which appears as if it is slithering through the universe.

The left ‘horn’ of the Cosmic Sea Lemmon is part of Herbig-Haro 399, a jet of plasma emitted periodically over centuries by a young protostar. [1] Embedded in the head of a sea lemon. See extension of jet. The observed changes allow researchers to measure the speed of the outflow and determine how much energy the protostar is injecting into these regions. The measurements will provide information about how newly formed stars interact with their surroundings.

Immediately below right is evidence of the counter jet: jagged orange and red lines running down the back of the sea lemon’s neck, where a natural V appears in the brown dust.

The darker, more triangular ‘horn’ to the right of the ‘head’ bears another young star at its tip. Zoom in to see a light red dot with a small jet. The green arc above it may be evidence that a circumstellar disk is being eroded by the intense ultraviolet light of nearby massive stars. The clearness of the area around this protostar shows that its construction is almost complete.

There is a small, blurry pillar just to the left of the Cosmic Sea Lemon. Most of the gas and dust in this column has evaporated, but the densest material remains at the top.

The streaks and sharp lines provide more clues about the activities of other young stars. See an example by looking near the center for a wavy angular line that starts in bright orange and ends in bright red. In image comparison, it appears to be moving, meaning it may be a jet fired by another actively forming star buried deep in the dust.

Prismatic ‘sea’ of color

In Hubble’s visible light observations, the clearest view is at the top left, where it is blue. Bright ultraviolet light coming from giant stars not in the visible field strips electrons from nearby gas, creating a glow, with the winds clearing away surrounding dust and creating a bubble.

At the top of the Cosmic Sea lemon head, bright yellow gas flows upward. This is an example of ultraviolet light penetrating dark brown dust, separating and destroying the gas and dust.

Many ridges and slopes of dark brown material will persist for a few million years, as ultraviolet light from the stars slowly eats away the gas. The densest regions are home to protostars [1]Which are unclear in visible light.

The rightmost corner is almost pitch black. This is where the dust is densest. The stars visible here may not be part of this star-forming region – they may be in the foreground, closer to us.

Now, scan the scene for glowing orange orbs. These stars have completely formed, leaving the space around them clear. In millions of years, the gas and dust that make up the nebula will disappear – and only the stars will remain.

Unprecedented Longevity, Constant Search

Hubble’s diverse instruments and the wide range of light it collects – from ultraviolet to near-infrared – have helped researchers make unprecedented discoveries for decades and supply new data every day, which will inevitably lead to more information.

Over the past year, Hubble has enabled discoveries ranging from remnants of early galaxy formation to a galaxy so faint it’s nearly invisible to unknown cosmic anomalies with the help of AI. Researchers observed asteroids colliding in another star system for the first time, while Hubble captured a comet suddenly disintegrating in our own solar system. The long-held prediction that our galaxy would collide with Andromeda in the distant future was challenged by a new study using data from Hubble and ESA’s Gaia. Hubble also tracked the interstellar comet 3I/ATLAS that unexpectedly appeared in the Solar System last year, helping to rapidly estimate its size.

Hubble’s 36th year of operation has brought even more impressive views of the universe. These included the star-forming region N11 in the Large Magellanic Cloud, balls of stardust forming the Egg Nebula, the Cat’s Eye Nebula with ESA’s Euclid and a brand new image of the famous Crab Nebula. Hubble also revealed the burning heart of M82, the rotating spiral galaxies UGC 11397 and Arp 4, the dust rings around the galaxy NGC 7722, the bright stars of the globular cluster NGC 1786, and the giant galaxy cluster Abell 209.

The telescope has made more than 1.7 million observations so far. Nearly 29,000 astronomers have published peer-reviewed science papers using Hubble data collected over the telescope’s 36-year lifetime, resulting in more than 23,000 publications, with nearly 1100 publications in 2025 alone. Starting in 2022, researchers will regularly combine Hubble observations with observations from the NASA/ESA/CSA James Webb Space Telescope to further expand discovery opportunities.

notes

[1] A protostar is a mass of interstellar gas and dust in the process of collapsing as a star.

More information

The Hubble Space Telescope is a project of international collaboration between ESA and NASA.

Link