NASA | GSFC | STScI | HubbleSite | ESA Hubble | 2023 May 23
Astronomers using the NASA/ESA Hubble Space Telescope have come up with what they say is some of their best evidence yet for the presence of a rare class of intermediate-sized black holes, having found a strong candidate lurking at the heart of the closest globular star cluster to Earth, located 6000 light-years away.A Hubble Space Telescope image of the globular star cluster, Messier 4. The cluster
is a dense collection of several hundred thousand stars. Astronomers suspect that
an intermediate-mass black hole, weighing as much as 800 times the mass of our
Sun, is lurking, unseen, at its core. Credits: ESA/Hubble, NASA
Like intense gravitational potholes in the fabric of space, virtually all black holes seem to come in two sizes: small and humongous. It’s estimated that our galaxy is littered with 100 million small black holes (several times the mass of our Sun) created from exploded stars. The universe at large is flooded with supermassive black holes, weighing millions or billions of times our Sun’s mass and found in the centers of galaxies.
A long-sought missing link is an intermediate-mass black hole, weighing roughly 100 to 100,000 times our Sun's mass. How would they form, where would they hang out, and why do they seem to be so rare? ...
Hubble’s unique capabilities have now been used to zero-in on the core of the globular star cluster Messier 4 (M4) to go black-hole hunting with higher precision than in previous searches. “You can’t do this kind of science without Hubble,” said Eduardo Vitral ...
Vitral’s team has detected a possible intermediate-mass black hole of roughly 800 solar masses. The suspected object can't be seen, but its mass is calculated by studying the motion of stars caught in its gravitational field, like bees swarming around a hive. Measuring their motion takes time, and a lot of precision. This is where Hubble accomplishes what no other present-day telescope can do. Astronomers looked at 12 years' worth of M4 observations from Hubble and resolved pinpoint stars. ...
Has Gaia Found Missing Link in Black Hole Evolution?
ESA | Science & Exploration | Gaia | 2023 May 23
An Elusive Dark Central Mass in the Globular Cluster M4 ~ Eduardo Vitral et al