This document discusses using population synthesis modeling to estimate the number of eclipsing binary stars that could contaminate exoplanet detections in the PLATO 2.0 mission. It describes generating synthetic binary star systems, evolving them, analyzing their light curves to determine transit depths, and applying this to simulated PLATO fields to output the expected number of eclipsing binaries at different transit depths. The results from simulations of random inclinations for binaries in patches of the PLATO northern field are also presented. Future work discussed includes calculating blend probabilities and applying the method to other surveys.

1. PHD Project Work – E. FarrellPHD Project Work – E. Farrell
Eclipsing Binary
Statistics
… in the PLATO
2.0 Field

2. PLATO 2.0 MissionPLATO 2.0 Mission
PLAnetary Transits & Oscillations of stars

3. PLATO 2.0 MissionPLATO 2.0 Mission
Long-duration Observatio:
continuous observations for two
sky pointings, lasting a
minimum of 2 years
Step-and-Stare Phases:
consisting of shorter-period
observations of several sky
fields, each for a min. 2 months

Ensemble of 32 cameras

bandpass 500 – 1050 nm

monitoring for bright stars
m > 8 mag.

Field of View 1100 deg^2

4. PLATO 2.0 MissionPLATO 2.0 Mission
PLAnetary Transits &
Oscillations of stars
Plato ESA presentation 2014
Will provide data on Exoplanets:
•mean density
composition (rocky, mini-gas)
constrain atmosphere scale
heights
•albedo and its diversity
indicative for clouds, hazes
•accurate ages
evolutionary pathways
•characterized host stars
incident flux, stellar activity

5. Transit MethodTransit Method

6. ProblemProblem: Exoplanet False Positives: Exoplanet False Positives

7. Solution: Estimate False Positives
1. Population Synthesis:
Generate synthetic binaries
2. Apply to
PLATO fields
3. Output number of
Eclipsing Binaries at
certain transit depths

8. Why estimate False Positives?

Generate statistics on field contamination from
Eclipsing Binaries

provide input on field placement for PLATO.

9. Population SynthesisPopulation Synthesis 'BiSEPS''BiSEPS'

Binary & Stellar Evolution
Population Synthesis
Willems & Kolb (2002, 2004)

Single and Binary system
evolutionary tracks -
ZAMS up to 13 Gyrs

Evolve millions of
systems - analytical stellar
evolution functions
Hurley, Pols & Tout (2000)

10. Population SynthesisPopulation Synthesis 'BiSEPS''BiSEPS'

Calculates Mass Loss,
Roche lobe overflow, angular
momentum losses & magnetic
braking

Galatic Disk modeled as thin
and thick disk with
solar and sub-solar metallicities

11. Eclipsing BinariesEclipsing Binaries

Specialised Software - “JKTEBOP”
analyses light curves of detached eclipsing binaries
(John Southward – Keele University)

Sophisticated –
calculates times of minimum light, spectroscopic light
ratios, third light values, orbital eccentricities
Adapted by
Rob Farmer,
Open University
to output
transit
depths

12. ResultsResults
Start with PLATO
Northern 'Long
Stare' field
Focus on 5 x 5
degree patch

13. ResultsResults

14. Random inclination – 5 simulationsRandom inclination – 5 simulations

15. Random inclination – 100 simulationsRandom inclination – 100 simulations

16. Future WorkFuture Work
Blend probabilities:
Scan field for binaries & single stars within 1 pixel

17. Future WorkFuture Work
Apply to
other
surveys

18. Future WorkFuture Work
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