EXOPLANETS

Experimental Lab

THE FIRST: PSR B1257+12a, b, & c

• Found in 1992 &

1994 by

Wolszczan+

• Smallest extra-

solar bodies ever

found, including 1

the size of the

moon

• Demonstrate

alternative planet-

forming

mechanisms

THE FIRST AROUND A NORMAL STAR: 51 PEGASI b

Fomalhaut b (“Dagon”) HR 8799 b, c, d, & e

CAN WE SEE EXOPLANETS DIRECTLY? A FEW (ALL GIANTS).

FOR THE REST, WE HAVE…LOTS OF OPTIONS

• Transit photometry

• Transit timing/duration

variation

• Reflection/emission

modulation

• Radial velocity (↓)

• Pulsar timing

• Gravitational

microlensing

TRANSIT PHOTOMETRY

• Record starlight intensity/photon flux

over time; watch for periodic dimming

• Compute tentative orbital parameters

& plan for >2 follow-up observations

THE DIFFERENCE A STAR MAKES

DO TRANSIT PHOTOMETRY, GET REFLECTION/EMISSION

MODULATION FOR FREE

THE KEPLER MISSION

EXOPLANET POPULATIONS“Hot Jupiters”

(51 Peg b was

prototype)Jupiter

analogs

Mini-Neptunes

/ Super-Earths

THE HABITABLE ZONE (HZ, OR GOLDILOCKS ZONE)

E.g. Kepler-186f is the

most Earth-like (1.4 ME)

planet found in the HZ

of another star to date.

The HZ also evolves with

time – not just at the end of

a star’s life but throughout.

E.g. the sun brightens ~10%

every 1 billion years

PROCEDURES

• All the instructions are given in the widget

• Fill out all 4 columns on your data sheet,

then answer the 3 “your report” questions

• FOR NEXT WEEK: Read “Features of the

Moon”