ODonovan

An Automated Wide-Field Search for Transiting Hot Jupiters: 

An Automated Wide-Field Search for Transiting Hot Jupiters Francis T. O’Donovan November 24th, 2003

Slide2: 

Know of 110 ESPs  75 from Marcy’s Doppler surveys Have precise Mass and Radius for only 2  2 Transiting Planets! With Mass and Radius, estimate  and g. Also, test models of system formation Can explore Planetary Atmosphere Know Period - Doppler observations less time consuming

Basic Variables and Calculations: 

Basic Variables and Calculations Radius of Planet (rp) and Star (R*) Semi-Major Axis of Orbit (a) Transit Latitude () and Duration () Probability of Transiting (p)

Transiting Hot Jupiters: 

Transiting Hot Jupiters Jupiter-mass planets within 0.1 AU of their host star Probability of transit, p ~ 10% Flux decrement ~ 0.01 mag Periods of 3-7 days Transits last 2-6 hours (depends on v, r, ) Need to monitor 3000 stars for 1 transit. (Optimistic? Or TDA problems?)

Sleuth: The Palomar Planet Finder: 

Sleuth: The Palomar Planet Finder f/2.8 4-inch camera lens imaging a 6º6º FOV onto 2k2k CCD SDSS g’,r’,i’,z’ filters Automated nightly observations with minimal supervision Network of Telescopes: STARE (T.M. Brown, Tenerife), PSST (E.W. Dunham, Arizona). Better longitudinal coverage Sleuth in clamshell enclosure at Palomar

The Hercules Field: 

The Hercules Field Monitored 10,000 stars (9andlt;Randlt;16) 40 clear nights in May andamp; June 2003 Overall RMS precision of better than 1% for the brightest 2000 stars Photometric RMS vs. R magnitude for Hercules stars 52 Her: (,) ≈ (16h,+45°) ; (l,b) ≈ (72°,+40°)

Analysis of Hercules Data: 

Analysis of Hercules Data STARE code  calibrated and cleaned light curves Kovács et al.’s TDA  search for transits with P between 1.5 and 7.5 days Result: No Planetary Candidates! Only eclipsing binaries Injected simulated transits and attempted recovery 85% of 0.02 mag transits recovered ; 50% of 0.01 mag transits Sample Sleuth light curves for eclipsing binary systems

The Next Steps: 

The Next Steps Current field in Andromeda - lower Galactic latitude [42 And: (,) ≈ (01h,+47°) ; (l,b) ≈ (126°,-15°)] Possible TDA improvement - Tingley (2003) Examine cleaning pipeline - throwing out transits? Using Sherlock for preliminary false positives rejection - high precision, multi-color, high angular resolution Observe planetary candidates with KECK/HIRES

Slide9: 

Doppler Spectroscopy: 

Doppler Spectroscopy Measures the period, semi-amplitude and eccentricity of orbit, and hence the semi-major axis. Also measures minimum mass. Jupiter induces v of 13 m/s Earth - v = 0.1 m/s Difficult to detect planets if v andlt; 10m/s or P andgt; 10 y Star spots!

Slide11: 

Path is ellipse with angular semi-major axis,  Know M* spectral type andamp; luminosity class, a from RV, d from parallax Keck - astrometric precision of 20 as, SIM - 4 as Good for long periods Jupiter orbiting the Sun viewed from 10 pc - 500 as Earth - 0.3 as

Transit Search Campaigns : 

Transit Search Campaigns EXPLORE (Deep Galactic Plane, CTIO/CFHT) STARE (Bright stars) VULCAN (6000 stars Vandlt;13, Mount Hamilton) OGLE (1.3m, Las Campanas, Galactic Disk andamp; Bulge Stars, 50,000 Stars) COROT (First high precision photometric satellite, French CNES) KEPLER(1.4m, Satellite, 100,000 dwarf stars for 4 years, 10^-5 precision) PISCES(Open Cluster) Transitsearch.org (Monitor known planetary systems)

Micro-lensing: 

Micro-lensing Focusing and amplification of l ight rays from distant source by intervening obejct Deviations (hours for Jupiters to days for earth of 1-20% to the light curves of background sources undergoing a microlensing event which lasts ~ 1 month. Survey many stars at once.

Slide14: 

Slide15: 

What Went Wrong: 

What Went Wrong Guiding problems - Fixed with firmware upgrade Field in Lyra abandoned when CCD damaged - Fixed at JPL Linux box offline after recent Palomar power fluctuations - Power supply replaced

Imposters & How to Spot Them: 

Imposters andamp; How to Spot Them Grazing incidence equal-size stellar binaries Central transit of small star in front of larger one Stellar blend: light from eclipsing binary blending with that of third star Transiting brown dwarf or late M dwarf They present a V-shaped rather than flat-bottomed eclipse Low precision (~ km s-1) Doppler observations reveal stellar mass Color-dependent transit depth of stars of different colors High (?) precision radial velocity observations removes mass degeneracy

HD 209458 b: 

HD 209458 b Star - G0V, 1.1 Msun, 1.1 Rsun, 47 pc, V=7.65 Planet - 1.34Rj, 0.6Mj, i=86deg, P=3.5d, a=0.05 AU v=80 m/s, transit depth=0.017 mag HST Observations of HD 209458 - Broke radius degeneracy: slope of ingress and egress determined R* Atmosphere - absorption of sodium, as predicted by simulations - clouds?, photoionizaiton of sodium by stellar flux?

OGLE-TR-56: 

OGLE-TR-56 Star is faintest (V=16.6) and most distant (1 kpc) known to have planet Shortest period known - 1.2 d 0.9 Mj, a=0.02 AU, R=1.3 Rj. Transit depth 13 mmag Used Kovacs et al.’s TDA - significant improvement over previous search

Pipeline: 

Pipeline Calibration of standard image Daophot - find and phot Multi-color coordinate transformations Transformation from x,y to RA,DEC Determine magnitudes and positions Combine multiple nights into one timeseries Remove systematically erroneous components Average photometry after frame offsets applied Transit search!

Kovacs et al.: 

Kovacs et al. Least squares fit of step functions to the folded signal corresponding to various trial periods SDE: signal is stellar brightness within the transit, relative to brightness outside the transit ; noise is expected scatter of the measured average of the stellar brightness inside the transit Want SDE andgt; 6.