Question

1. (a) What types of extrasolar planet detection methods exist? (b) What are the current limitations?

2. Are all the planets being found similar to the planets in our solar system? Give some examples. (Hint: Check out the Kepler Telescope Data)

3. What is the main problem(s) with a planet in the habitable zone orbiting a red dwarf star?

4. What is the main problem(s) with a planet in the habitable zone orbiting a blue supergiant star?

Answer 1

1 a) three types of extrasolar planet detection are- Doppler technique, astrometry,transit photometry, pulsar timing, coronagraphy

doppler technique-this technique uses the study of change in wavelength of light from the stars.

astrometry-it is the study of orbital motion of stars.to detect the planet.

transit photometry-this method uses the study of brightness of the star and the change in brightness of the star when it crosses a planet.

pulsar timing-this method uses the changes in the time difference of the pulse arrival

coronagraphy- this method uses the technique of blocking the starlight which helps in detecting the exoplanets.

the limitations are-

1) in photometry we can only detect size of planets which are of the size of the earth

2) the study of orbital motion of stars is affected by the distance , so if the distance is too large of the detected planet, then the time required by to record the orbital motion will be less.

3) the limitations of the doppler method is that it cannot give the true mass of the planet detected if movement of the star is at angle to the observer rather than in straight line

4) in pulse timing , the nature and shape of the pulse affect the time difference.