Citizens and AI Join the Search for the Milky Way’s Hidden Black Holes
gravitational microlensing
A massive object bends and briefly brightens a star’s light.
light curve
A graph showing how a star’s brightness changes over time.
TESS
A NASA space telescope that measures changing star brightness.
What is happening
Astronomers are asking the public to help find hidden black holes in the Milky Way. Estimates suggest the galaxy may have produced more than 10 million black holes during its roughly 13-billion-year history. Researchers have identified only about 70 so far. Black Hole Hunters, a public science project, asks volunteers to inspect telescope data for patterns that could reveal more. The Space.com report describes the project as a search for these missing objects.
Why they are hard to see
A black hole gives off no light of its own. Its gravity is the main clue. Many massive stars form in pairs. One can collapse into a black hole, while its companion survives. The two objects may continue orbiting each other. If the orbit lines up with Earth, the black hole can pass between its companion and us. Its gravity bends and magnifies the companion’s light. The star briefly looks brighter. This effect is called gravitational microlensing. The project describes this kind of event as gravitational self-lensing.
How the search works
The project uses TESS, a NASA space telescope that repeatedly measures star brightness. TESS was designed mainly to search for exoplanets. Its time-based measurements can also show a brief brightening. The project turns millions of measurements into light curves, or graphs of brightness over time. An AI-assisted computer system makes an initial search. It can find obvious patterns quickly. But stellar flares and natural pulsations can create false positives. Those changes may look like black-hole signals.
Why humans still matter
Volunteers inspect the harder graphs. They look for a rise in brightness that later returns to normal. Each graph is shown to several people. Their answers are combined, so one mistake is less likely to control the result. This partnership uses different strengths. Computers process huge data sets quickly. People can notice unusual shapes in messy data. Researchers then receive a shorter list of stars worth checking.
What is confirmed
The confirmed result is the search method. TESS supplies the measurements. Volunteers and software help narrow the targets. Since the project launched in 2021, nearly 23,000 volunteers have completed more than 12 million classifications, according to the project information. That shows a large public effort. It does not mean the project has already confirmed thousands of black holes.
What remains unknown
A brightening is only a candidate clue. A stellar flare or pulsation can look similar. Researchers need follow-up observations before calling a candidate a black hole. They may measure whether the visible star moves under the pull of an unseen companion. These measurements take time and telescope resources. The Black Hole Hunters research page explains that a good shortlist helps researchers spend that effort carefully.
What comes next
The team is still analyzing an earlier search using SuperWASP, a ground-based star survey. It also plans to use observations from Euclid, a European space mission, and NASA’s Nancy Grace Roman Space Telescope. The next test is whether candidates survive independent observations. If they do, astronomers may confirm hidden black holes. For now, the news is about expanding the search, not announcing a finished discovery.
People and Computers Search for Hidden Black Holes
📰 Full story: Citizens and AI Join the Search for the Milky Way’s Hidden Black Holes
A public project asks people to spot clues in star-brightness graphs.
TESS
A NASA space telescope that measures star brightness repeatedly.
light curve
A graph showing how bright a star is over time.
gravitational lensing
Gravity bends light and can make a star look brighter.
💡 The gist
- Hidden black holes may be common in our galaxy.
- Their gravity can make a nearby star look brighter.
- People and computers check star graphs together.
Black Hole Hunters is a public science project. It asks volunteers to inspect star data. The project uses TESS, a NASA space telescope. TESS measures star brightness again and again.
A black hole makes no light of its own. That makes it hard to see. Many large stars have companion stars. One star can become a black hole. The companion can survive and keep orbiting it.
Sometimes the orbit lines up with Earth. The black hole then passes between the star and us. Its gravity bends the star’s light. The star can briefly look brighter. This effect is called gravitational lensing.
The project turns TESS measurements into light curves. A light curve is a graph of brightness over time. A computer checks millions of possible signals first. It can remove many easy examples quickly.
Computers can still make mistakes. Star flares can look like black hole signals. Star pulsations can look similar too. Volunteers inspect the harder graphs. Several people review each graph. Their answers are combined. This reduces the effect of one person’s mistake.
The project does not confirm a black hole from every bright peak. Each candidate needs follow-up observations. Scientists may measure whether the star moves. An unseen companion could pull on it. These measurements take time and telescope resources.
The project began in 2021. Nearly 23,000 volunteers have made more than 12 million classifications. Researchers also plan to study more data. Future sources include Euclid and the Nancy Grace Roman Space Telescope. The key question is simple. Will a candidate survive careful checks? If it does, people may confirm a hidden black hole.
People Help Find Hidden Black Holes
📰 Full story: Citizens and AI Join the Search for the Milky Way’s Hidden Black Holes
People look at star graphs for clues about dark space objects.
black hole
A very heavy space object that cannot let light escape.
TESS
A NASA space telescope that watches stars.
A black hole is a very heavy space object. Light cannot escape it.
So, we cannot see the black hole itself.
But its pull can bend a nearby star’s light. The star may look brighter for a short time.
Black Hole Hunters is a public project for finding these clues.
People look at graphs from TESS, a NASA space telescope. The graphs show how bright stars are over time.
A computer checks many graphs first. People check the tricky ones too.
Several people look at each graph. Their answers are put together. This helps catch mistakes.
Scientists then use telescopes to check the best clues. A bright spot is not proof yet. The team still needs more observations.