AGENT EXOPLANET

Sarah, Ellie, Adan and Sruthy

The Transit Method

• The main disadvantage of the transit method is that for us to detect a planet, the orbit must be precisely aligned with our point of view.

Our Project

TrES-3b

Jupiter compared to TrES-3b

Mass 1.199±0.052 MJ

Orbital Period 2.4706 ± 0.00001 d

Radius 1.341 ± 0.081 RJ

Surface gravity 3.284±0.016 g

Temperature -

Distance 750±30 ly

Type Gas Giant

Star GSC 03549-02811

Constellation Draco

Duration of transit 0.042days

Dip in brightness 0.025

Ratio of planet to star radius 0.16

Theory•Radius, mass of star, as well as planet’s period, estimated through observation

•Then you can calculate:1) semi-major axis2) orbital speed3) radius4) transit duration5) impact parameter 6) Inclination

• Calculations based on Newton & Kepler’s Laws.

GJ-1214 b

Mass 6.55 ± 0.98 M⊕

Orbital Period 1.5804 ± 1.6x10-7d

Radius 2.678 ± 0.13 R⊕

Surface gravity 0.91 g

Temperature 393–555 K

Distance 42 ly (12 pc)

Type Super-Earth

Star GJ 1214

Constellation Ophiuchus

Duration of transit 0.039 days

Dip in brightness 0.0144

Ratio of planet to star radius 0.12

Qatar-1b

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Mass 1.09±0.08 MJ

Orbital Period 1.4200 ± 1.6x10-05 days

Radius 1.164 ±0.06 R

Surface gravity -

Temperature 1380±45 K

Distance 550 ly (169 pc)

Type Gas Giant

Star Qatar-1

Constellation Draco

Duration of transit 0.060 days

Dip in brightness 0.025

Ratio of planet to star radius 0.16

WASP-2bSP-2b

Jupiter compared to WASP-2bMass 0.847 ± 0.045 MJ

Orbital Period 2.1522 ± 4x10-7 days

Radius 1.079 ± 0.033 RJ

Surface gravity 3.279 ± 0.036 g

Temperature 1300 ± 54 K

Distance 470 ly (144 pc)

Type Gas Giant

Star WASP-2

Constellation Delphinus

Duration of transit 0.060 days

Dip in brightness 0.019

Ratio of planet to star radius 0.14

Detecting Exoplanets

Using Radial Velocity or the Doppler Method

What is radial velocity?

Velocity along the line of sight toward or away from the observer.

This diagram shows how an orbiting planet will change the position of the star it orbits due to its gravitational tug.

What is spectroscopic radial velocity and how can it be used to determine a planet’s radial velocity?

S.R.V is the radial component of the velocity of the source at emission and the observer at observation, as determined by spectroscopy.

Advantages and Disadvantages of using the radial velocity method.

Advantage:• The planet's

eccentricity can be measured directly.

Disadvantage:• Can only estimate a

planet’s minimum mass.

Easier to detect planets orbiting low mass stars because....

• More affected by the planets’ gravitational tug.

• Generally, the planets rotate more slowly when orbiting a low mass star.

R.V. Method is the most productive method used...

456 Exoplanets – 31 confirmed and 323 candidates.

Of the 31 confirmed Exoplanets – 1 Exoplanet has been identified as having the potential for habitability – Gliese 581-d