Search and Ye Shall Find
Tom Dormer discusses a novel technique to detect black holes
Scientists at Harvard University and the Black Hole Initiative (BHI) have developed a new method to detect black holes to find the famed Planet Nine.
The new method, developed by Dr. Avi Loeb, Frank B. Baird Jr., and Amir Siraj, is based on the observation of accretion flares that result from the gravitational capture of nearby comets.
Close to a black hole, approaching smaller objects melt due to heat from the collection of interstellar gas onto the black hole, as explained by a quote from Siraj. The extreme heat melts the object into flares that are pulled into the accretion disk. These flares illuminate the environment for a short time, meaning the presence of a black hole can be temporarily detected. These ‘accretion flares’ could be detected by the future Legacy Survey of Space and Time (LSST) mission.
This method is expected to detect planet-mass black holes up to 100,000 astronomical units (15,000,000,000,000 km) away and could be capable of putting limits on the fraction of dark matter in primordial black holes.
This method is expected to detect planet-mass black holes up to 100,000 astronomical units
‘Planet Nine’
The first candidate for detection using this method- which uses the future Legacy Survey of Space and Time mission- is the renowned ‘Planet Nine’,
The consideration of a ninth planet in the Solar System began as an explanation of the unusual clustering of objects beyond Neptune. The subject of much speculation, most theories suggest Planet Nine has a mass of about 10 times that of the Earth and orbits around 20 times further away.
If found, it would be the first new planet detection in over 2 centuries (excluding Pluto) and would become an unprecedented scientific discovery. As Dr. Loeb explains, finding such a planet in our metaphorical backyard would be like discovering a previously unknown cousin has been living in your shed without your noticing.
The Black Hole Theory
The alternate theory is that Planet Nine could be a grapefruit-sized black hole with a mass five to ten times that of the Earth. The failure to detect light from Planet Nine’s predicted location so far has made this idea more interesting.
The alternate theory is that Planet Nine could be a grapefruit-sized black hole
It is hoped that LSST will be able to detect this black-hole using the accretion flare method, with its large field of view meaning it will able to survey the broad region Planet Nine is predicted to reside in.
If a black hole is found, Loeb feels it will instantly raise fresh questions, such as how it got there, how it got its properties, and whether it impacted the history of the solar system- not to mention whether there are more like it.
LSST is currently still under construction, but scientists expect it to take its first observations in late 2022.
