Indian astronomers, utilizing the Devasthal Optical Telescope (DOT), have successfully detected and precisely measured the mass of an Intermediate-Mass Black Hole (IMBH) in a faint galaxy approximately 4.3 million light-years away — a significant step for India in the field of observational astrophysics.

What is an Intermediate-Mass Black Hole (IMBH)?

• Definition:
  IMBHs are mid-sized black holes with masses ranging from 100 to 100,000 times that of the Sun.
  They occupy the mass range between stellar-mass black holes and supermassive black holes.

• Key Characteristics:

  • Mass of this IMBH: ~22,000 times the mass of the Sun.

  • Orbital Behavior: Surrounding gas clouds orbit at a distance of about 2.25 billion kilometers (~15 times the Earth-Sun distance).

  • Feeding Rate: Consuming matter at only 6% of its Eddington limit (the theoretical maximum rate of accretion).

• Detection:
  IMBHs are extremely faint and hard to spot unless they are actively accreting matter, which produces detectable radiation signals (primarily X-rays and optical emissions).

About Devasthal Optical Telescope (DOT)

• Location:

  • Situated at Devasthal, near Nainital, Uttarakhand, India.

  • Geographical Coordinates: ~29.36° N latitude, 79.68° E longitude.

  • Altitude: Approximately 2,450 meters above sea level — providing excellent sky transparency and low atmospheric interference.

• Telescope Features:

  • Diameter: 3.6 meters — the largest optical telescope in India.

  • Commissioned: 2016.

  • Managed by: Aryabhatta Research Institute of Observational Sciences (ARIES), an autonomous institute under the Department of Science and Technology (DST), Government of India.

• Importance:

  • Designed for deep-sky surveys, stellar studies, and galactic exploration.

  • Has significantly boosted India's capacity for cutting-edge astronomical research.

Understanding Black Holes

• Definition:
  A black hole is a region in space where the gravitational pull is so strong that nothing, not even light, can escape from it.

• Formation:

  • Typically formed when a massive star exhausts its nuclear fuel and collapses under its own gravity.

  • The core's collapse produces a singularity, and the outer layers are either expelled or drawn into the black hole.

• Types of Black Holes:

• Type Mass Range Example Stellar-mass Black Hole ~3–20 solar masses Cygnus X-1 Intermediate-Mass Black Hole ~100–100,000 solar masses The newly discovered IMBH Supermassive Black Hole Millions to billions of solar masses Sagittarius A* at the center of the Milky Way