Recently JWST captured a plume of gas and dust streaming from a forming star, with a spiral galaxy in the background.

Key Findings of JWST

• The composite image, released by NASA and ESA resembles a rocket’s contrail moving towards the galaxy.
• Located 625 light-years away, this is one of the closest star-forming regions in the Milky Way.

About Star

• A star is a giant sphere of extremely hot, luminous gas (mostly hydrogen and helium) held together by gravity. 
  • A few examples of well-known stars are Pollux, Sirius, Vega, Polaris, and our own Sun.

Life Cycle of a Star

• Birth Stage
  • Nebula: A vast cloud of gas (hydrogen, helium) and dust, where stars begin.
  • Protostar: Gravity collapses the nebula, forming a dense, spinning, and heating region.
• Main Sequence Phase: The longest phase, where hydrogen fusion occurs in the core, sustaining the star.
  • The Sun is currently in its main sequence phase.
• Post-Main Sequence Evolution (Old Age)
  • Low to Medium Mass Stars (e.g., Sun): Expand into Red giants after hydrogen depletion.
  • Massive Stars: Become Supergiants, fusing heavier elements like carbon and oxygen.
• End Stages: Death and Remenants
  • Low to Medium Mass Stars: Outer layers eject as a planetary nebula; the core becomes a white dwarf.
    • It remains stable as a Dwarf star if the mass is under Chandrasekhar Limit (1.4 solar masses).
  • High Mass Stars: Collapse into a neutron star (1.4–3 solar masses) or a black hole if above 3 solar masses.

James Webb Space Telescope (JWST)

• Successor to Hubble: Launched in 2021, it observes the universe in infrared wavelengths.
• Enhanced Capabilities: Provides detailed imaging of celestial objects, detecting early galaxies and star formation.
• Major Discoveries: Captured clear images of star birth, exoplanets, and distant galaxies.

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