For decades, astronomers have searched for evidence of black holes being ejected from their home galaxies, but no definitive proof had ever been found—until now.
A mysterious celestial object, nicknamed SDSS1133, has been spotted floating in interstellar space, about 2,600 light-years from the center of a dwarf galaxy.
Initially mistaken for a supernova, this enigmatic entity may actually be the first-ever confirmed orphaned black hole.
If true, this discovery could reshape our understanding of how black holes behave after galaxy mergers, challenging some long-standing assumptions about their movements and interactions.
A Black Hole Lost in Space?
When SDSS1133 was first observed in 2005, astronomers classified it as a supernova, the explosive death of a massive star.
However, a closer examination revealed something puzzling—the object has been visible for over 63 years.
Supernovae are short-lived, brightening dramatically before fading within weeks or months.
The idea that SDSS1133 has persisted for decades suggests something far more unusual is at play.
A new study, published in the Monthly Notices of the Royal Astronomical Society, now proposes a groundbreaking theory: SDSS1133 might be a black hole that was forcefully ejected from its home galaxy, Markarian 177, after a 2.7-billion-year-long cosmic collision.
If confirmed, this would be the first direct evidence of such an event, providing a rare glimpse into the violent interactions between galaxies.
How Do Black Holes Get Kicked Out?
Black holes typically reside at the centers of galaxies, anchored by intense gravitational forces.
However, when galaxies collide, their central supermassive black holes can interact in ways that lead to one being violently flung out into intergalactic space.
This process, known as a gravitational recoil, occurs when the immense energy of merging black holes isn’t perfectly symmetrical.
The resulting imbalance can give the smaller black hole a powerful “kick,” sending it on a one-way journey through space.
The Evidence That Shattered the Supernova Theory
SDSS1133 isn’t behaving like any known supernova. Several observations contradict its classification as a dying star:
- Observed for Over 60 Years – Typical supernovae last a few months at most.
- Unusual Brightening – The object has become brighter over the past two years, an unexpected behavior for a fading explosion.
- Extreme Location – Positioned 2,600 light-years from the center of Markarian 177, it seems out of place for a supernova but perfectly in line with a runaway black hole’s expected trajectory.
What If It’s Not a Black Hole at All?
While the black hole theory is the most compelling, there’s another, even rarer possibility: SDSS1133 could be an extremely unusual type of star known as a luminous blue variable (LBV).
These stars undergo massive eruptions that make them appear supernova-like.
However, there’s a problem with this idea. If SDSS1133 is indeed an LBV, it would be the most persistent eruption of its kind ever recorded, lasting for over seven decades.
That kind of sustained outburst is unprecedented, leading many astronomers to remain skeptical of the star theory.
Observing in Ultraviolet
To solve the mystery, astronomers plan to observe SDSS1133 in ultraviolet wavelengths in the coming year.
Ultraviolet light can reveal critical details about the object’s temperature, composition, and surrounding environment.
If SDSS1133 turns out to be a runaway black hole, it would confirm a long-theorized but never-before-seen cosmic event.
Why This Discovery Matters
If SDSS1133 is a black hole ejected from Markarian 177, it would challenge many assumptions about galactic evolution.
Black holes are often thought to be immovable giants, locked at the heart of their host galaxies.
Finding one hurtling through space suggests that black holes may be far more dynamic and mobile than previously believed.
Additionally, this discovery could help explain similar rogue black hole candidates that have been detected but not yet confirmed.
It might also provide new insights into the role black holes play in shaping galaxies over cosmic time.
Final Thoughts
For now, SDSS1133 remains a mystery—but not for long. With new observations on the horizon, we may soon know whether we’ve discovered the first-ever runaway black hole or an unprecedented stellar event.
Either way, this finding is pushing the boundaries of what we know about the universe and proving that even in the vastness of space, there are still surprises waiting to be uncovered.
Sources: Monthly Notices of the Royal Astronomical Society, Science, io9
