Transit Timing, Radius, Albedo, and Satellites of Extrasolar Planets with MagIC’s Upgrade

Transit Timing, Radius, Albedo, and Satellites of Extrasolar Planets with

MagIC’s UpgradeMercedes López-Morales

Carnegie-DTM

Extrasolar Planets to Date

•235 planets discovered to date:• 233 from Radial Velocities• 19 from Transits• 4 from Microlensing• … +4 pulsar planets

(Last update: May 10

2007) Main Future Goals•Physical characterization of known planets•Discovery of the first Earth-mass planets

TRANSITS: at present the richest source of information

• Planet-to-Star Radius Ratio• Orbital inclination and stellar limb darkening

• Planetary Albedos• Satellites around theplanets• Additional planets in those systems• Earth-mass planets

Transit Timing

from Agol et al. (2004)

Transit TimingCan detect extrasolar planets as small as 2-3

MEarth

based on eq. 1 of Holman & Murray (2005)

Transit Timing

From Seager & Mallén-Ornellas (2003)

= Rp / Rs

p = (T - F) / 2ph = light curve noise / sec

(t0) -2ph p1/2

Recent Transit Timing Attempts

Planet (t0) Transits Reference

TrES-1 ~100 sec 11 Steffen & Algol (2005)

HD189733b ~60 - 100 sec 5 Bakos et al. (2006)

OGLE-TR-113 ~12 - 71 sec 3 Gillon et al. (2006)

MagIC Upgrade

POETS: Portable Occultation,Eclipse, and Transit System.

- 512x512 pixel Frame-transfer CCD- 16 m pixels- > 90% QE up to 1 m- ≤ 6 e- readout noise- Full well ~ 200,000 e-/pixel- Three-stage Peltier cooler (-70C in air)

CCD47-20 chip from e2V technologies

- 1024x1024 pixel Frame-transfer CCD- 13 m pixels- > 70% QE between 0.4-0.8 m- ~ 2 e- readout noise- Full well ~ 100,000 e-/pixel- cooled at -120C (MagIC dewar)

POETS on Magellan Telescopes

OGLE-TR-56b on Magellan with POETS

25”

x 2

5”

FoV

OGLE-TR-56b OGLE image

60”

x 6

0”

FoV

Test Transit of OGLE-TR-56b on Magellan

- 2 sec exposure sequence in I-band- S/N = 400 per point, i.e. 2.5 mmags- Red-noise ~ 4.5 mmags

~0.43 mmags in 100 sec bins!

Performance of POETS

Observational Strategy

GOAL: 3-5 transits or more of each target per year 2-3 occultations per year

Bonus Material

• Error in Rp < 0.5% (assuming R* = 0)

• Satellites?

• Albedos - OGLE-TR-56b, 113b and 132b have P [1.0, 2.0] days - Could have Tsurf ~ 2500-3000K

- Occultations could be ~ 0.5 mmags deep

Parameter Precision Goals

Summary- The MagIC update will be able to improve light curve photometric precision on ground-based telescopes by a factor of 6.- That photometric precision improvement will allow:

- improvement on ground-based albedo detections at optical wavelengths.- improvement on detection of satellites.- improvements on planetary radius measurements- improvements on the detection of additional planets via transit timing.

- Transit timing data of particular interest for OGLE planets.

- Project fully funded by NASA Origins Program. Observations begin June 2007 with MagIC.

Project Members

Jim ElliotSara SeagerElisabeth AdamsAmanda Gulbis ……. all from MIT

David Osip (LCO, OCIW)

Mercedes López-Morales (CIW-DTM)