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Hubble Space Telescope Releases Images of Two Distinct Galaxies in Separate Surveys

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Hubble Captures Dual Views of Spiral Galaxies

Two distinct galaxies, one shared mission: understanding how galaxies form, evolve, and fuel their central black holes.

The NASA/ESA Hubble Space Telescope has produced stunning new images of two distinct galaxies: the intermediate spiral galaxy NGC 4654 and the barred spiral galaxy IC 486. These images were collected through separate observing programs studying galaxy structure, star formation, and active galactic nuclei.

Galaxy NGC 4654

Location and Structure

NGC 4654 is an intermediate spiral galaxy located approximately 72 million light-years from Earth in the constellation Virgo. It is a member of the Virgo Cluster, a large galaxy cluster. The galaxy exhibits a weak central bar structure and an asymmetric shape.

Asymmetry and Causes

The galaxy shows a rounded, clearly defined edge on one side and a long gas tail on the opposite side. Astronomers attribute this lopsided shape to two key factors:

  • Ram pressure stripping: NGC 4654 moves through the hot, rarefied intracluster medium at high velocity, compressing gas at its leading edge and dragging it behind.
  • Gravitational interaction: A fly-by interaction with the neighboring galaxy NGC 4639 approximately 500 million years ago stripped gas from one side of NGC 4654, limiting star formation in that region.

The galaxy's leading spiral arm is rich in stars and gas, while the opposite arm notably lacks stars — a direct visual record of its violent history.

Star Formation

Despite the effects of ram pressure stripping, NGC 4654 continues to form stars at a rate of nearly two solar masses per year — a rate comparable to other galaxies of similar size. Hubble data includes red-wavelength light from energized gas clouds where newborn stars reside; bright pink bubbles across the galaxy mark these star-forming regions.

Observing Programs

The data originate from two Hubble observing programs (ID 15654, 17502) aimed at linking gas in galaxies with star formation. These programs study prominent nearby galaxies to understand gas movement, the timing and location of star and star-cluster formation, and the impact of new stars on surrounding gas.

Galaxy IC 486

Location and Structure

IC 486 is a barred spiral galaxy located approximately 380 million light-years from Earth in the constellation Gemini. The image shows a bright central bar-shaped structure with spiral arms extending outward, some of which form a ring-like pattern.

Galaxy Characteristics

  • Color variations: The pale central region is dominated by older stars, while faint bluish regions in the surrounding disk indicate areas of recent star formation.
  • Dust structures: Wisps of dust are visible throughout the galaxy's structure, tracing regions of molecular gas where new stars may form.

Active Galactic Nucleus

A white glow at the galaxy's center comes from an active galactic nucleus (AGN). The AGN is powered by a supermassive black hole estimated to be more than 100 million times the mass of the Sun. The AGN generates intense radiation, including X-rays, that can outshine the rest of the galaxy. Galaxies with such active nuclei are classified as active galaxies.

The AGN's intense radiation can outshine the entire galaxy — a beacon powered by a black hole 100 million times more massive than our Sun.

Research Context

The image data comes from two Hubble observing programs (#17310 and #15444). Both programs aim to survey nearby active galaxies and record detailed images of their central black holes and surrounding stars.

A stated research goal is to understand how galaxies grow by linking large-scale structures (like bars and spiral arms) to nuclear activity. Researchers are using both expert classifications and citizen science through the Galaxy Zoo project. Scientists are also testing how large language models and other machine learning techniques can classify galaxy morphology — methods intended to support analysis of data from future telescopes including the Euclid telescope, the Vera Rubin Observatory, and NASA's Roman Space Telescope. The datasets from these programs are planned for public release.

Image Composition

The wide-field view of IC 486 includes distant background galaxies and foreground stars. Some stars display characteristic diffraction spikes. Distant galaxies appear as diffuse, orange-red smudges in the field of view.

Credits

  • Image of NGC 4654: NASA, ESA
  • Image of IC 486: ESA/Hubble & NASA, M. J. Koss, A. J. Barth