Summary of Extrasolar Planets and Detection Methods

Extrasolar Planets

• Total Confirmed Exoplanets: 6042.
• First Discovery: 1992.
• Detection Methods: Majority detected indirectly, few dozen imaged directly.

Detection Methods

Radial Velocity

• Detects the "wobble" of a star caused by a planet's gravitational influence.
• Identified by shifts in spectral lines of the star's spectrum.

Conditions for Effectiveness

• Works best with:
  • More massive planets
  • Planets close to their stars
• Less effective with lighter, distant planets.

Example Data

• 51 Pegasi b (Hot Jupiter):
  • Period (P): $4.2$ days
  • Observed velocity shifts recorded (m/s): $[-150, -100, -50, 0, 50, 100, 150]$.
  • Data variations observed over time indicate presence of multiple planets.

Transit Method

• Detects dimming of a star's light when a planet transits in front of it.
• Utilized by NASA missions (Kepler, TESS).
• Critical for identifying exoplanets' size and orbital characteristics.