Milky Way’s Core: Dark Matter Blob or Black Hole?

Milky Way’s Core: Dark Matter Blob or Black Hole?

The heart of our Milky Way galaxy, long believed to be dominated by a supermassive black hole, might harbor a more diffuse entity: a colossal blob of dark matter. New research suggests that the orbital paths of stars near the galactic center are as consistent with a dark matter cloud as they are with the supermassive black hole, Sagittarius A*. This intriguing possibility challenges decades of astronomical consensus and opens new avenues for understanding the enigmatic dark matter that pervades the universe.

Planetary Parade and Celestial Events Light Up February Skies

As February 2026 unfolds, stargazers have a celestial spectacle to enjoy: a ‘planet parade’ featuring six planets visible in the night sky. Mercury, Venus, Saturn, and Jupiter can be seen with the naked eye, while Uranus and Neptune require a telescope. This alignment, where planets appear in a line from our perspective, is a result of them being on the same side of the Sun as Earth. While not a rare event, occurring in February 2025 and 2022 previously, it offers a fantastic opportunity for observation. For the best viewing experience, the night of February 20th is recommended, with the crescent moon forming a line with Saturn, Mercury, and Venus just after sunset. Saturn will be particularly close to Venus around March 7th and 8th, forming a striking conjunction, though its low position above the horizon may make it difficult to spot from higher latitudes without a clear western horizon.

Adding to the celestial calendar, a lunar eclipse, often called a ‘blood moon’ due to its reddish hue, will be visible on the night of Tuesday, March 3rd. This phenomenon occurs when the Moon passes through Earth’s shadow. Earth’s atmosphere refracts sunlight, bending red light more than other colors, which then illuminates the Moon, casting a sunset-like glow. While a full eclipse will be visible in Australasia and parts of Asia, viewers in the Americas and other parts of Asia will witness a partial eclipse. The color of stars themselves offers another stargazing activity. The blue-white stars like Rigel and Bellatrix in Orion are hot, massive blue giants, emitting highly energetic blue light. In contrast, cooler, older red giant stars like Betelgeuse and Aldebaran appear yellowish-red, emitting less energetic light. This difference in color directly correlates with their surface temperatures.

Artemis Mission Faces Delays, UK Astronomy Funding Under Threat

The much-anticipated Artemis 2 mission, set to carry four astronauts on a lunar flyby, has been delayed. A critical ‘wet dress rehearsal,’ where the Space Launch System (SLS) rocket was fueled and tested, encountered a significant liquid hydrogen leak, halting the countdown. While engineers addressed the initial issue, a spike in the leak rate five minutes before the rehearsal’s end necessitated further work. NASA is now targeting a launch window in early March, a setback not entirely unexpected given the previous launch attempts for Artemis 1.

Closer to home, the UK’s astronomy and space science community faces potential drastic cuts to funding. Proposed reductions by the Science and Technology Facilities Council (STFC) could see budgets for astrophysics, particle physics, and nuclear physics drop by around 30%, with scenarios of 20%, 40%, and 60% reductions also outlined. These cuts are attributed to rising operational costs for the facilities managed by STFC, which are used across various scientific disciplines. However, only astrophysics and nuclear physics are expected to absorb these research budget reductions. Such cuts could significantly impact early-career researchers and PhD students, potentially leading to fewer job opportunities and reduced scientific output in the UK, a nation with a strong history in space science.

JWST’s ‘Little Red Dots’ Hint at Direct Collapse Black Holes

The James Webb Space Telescope (JWST) has revealed mysterious ‘little red dots’ in the early universe, objects that have puzzled astronomers. Initially thought to be growing supermassive black holes due to specific hydrogen emissions (broad lines in a galaxy’s spectrum), their properties don’t entirely align with expectations. Typically, supermassive black holes constitute about 0.1% of a galaxy’s stellar mass, and they should emit significant X-ray light. However, no such X-ray emission has been detected from these dots. This has led to alternative theories, including them being unusually compact galaxies.

A recent study by Pikuchi and collaborators proposes a compelling explanation: direct collapse black holes. Unlike stellar black holes formed from dying stars, direct collapse black holes are hypothesized to form when massive gas clouds collapse directly into a black hole, bypassing star formation and supernovae. This process could create black holes around a thousand times the Sun’s mass, providing a ‘shortcut’ for the rapid growth of supermassive black holes observed in the early universe. Pikuchi’s simulations show that the light signatures from gas around such a direct collapse black hole, especially when interacting with dust, closely match the observed spectra of JWST’s little red dots. Crucially, this model explains the lack of X-ray emission, as the extreme density required for direct collapse would trap most high-energy X-rays.

Revisiting the Milky Way’s Center: Dark Matter vs. Black Hole

The debate over the nature of the Milky Way’s central object has a new contender. While Sagittarius A*, a supermassive black hole, has been the long-standing conclusion, research by Cresby and collaborators suggests a dark matter blob could explain the observed stellar orbits equally well. For decades, astrophysicists have grappled with what lies at galactic centers, considering single supermassive black holes, swarms of smaller black holes, or diffuse dark matter concentrations.

Dark matter, which interacts gravitationally but not electromagnetically, would not emit or absorb light. The key difference lies in gravitational influence: a dense black hole pulls differently on nearby objects than a diffuse dark matter cloud of the same mass. While the differences are subtle, especially at greater distances, they should be measurable for stars in very close orbits. Cresby’s team analyzed the orbits of stars like S2 near the galactic center, finding that their paths fit both black hole and various dark matter models with minimal discernible differences, largely due to current limitations in observational accuracy.

However, the study also examined galaxy-wide rotation curves using data from the Gaia mission. Their dark matter model, extending to the galaxy’s outskirts, reportedly accounts for a slight slowdown in the rotation of stars at the edge, a feature also observed by Gaia. Furthermore, the researchers propose that a central dark matter cloud could, under specific conditions, mimic the shadow-like features observed by the Event Horizon Telescope (EHT) in its image of Sagittarius A*, producing a bright ring with a dark center. While this dark matter hypothesis is intriguing, the current evidence is not considered sufficient to overturn the extensive observational data supporting the supermassive black hole model. Future observations with enhanced precision are needed to definitively resolve this galactic mystery.

Source: Is the centre of the Milky Way a lump of DARK MATTER? | Night Sky News February 2026 (YouTube)