1. OGLE-2003-BLG-235/MOA-2003-BLG-53: A Definitive Planetary Microlensing Event David Bennett University of Notre Dame

2. Author List: I.A. Bond, A. Udalski, M. Jaroszynski, N.J. Rattenbury, B. Paczynski, I. Soszynski, L. Wyrzykowski, M.K. Szymanski, M. Kubiak, O. Szewczyk, K. Zebrun, G. Pietrzynski, F.Abe, D.P. Bennett, S. Eguchi, Y. Furuta, J.B. Hearnshaw, K. Kamiya, P.M. Kilmartin, Y. Kurata, K. Masuda, Y. Matsubara, Y. Muraki, S. Noda, K. Okajima, T. Sako, T. Sekiguchi, D.J. Sullivan, T. Sumi, P.J. Tristram, T. Yanagisawa, and P.C.M. Yock (the MOA and OGLE collaborations)

3. Real-Time Lightcurve Monitoring is Critical! Ian Bond (IFA, Edinburgh) noticed a caustic crossing for this event on July 23, 2003. He contacted the telescope and requested additional images The requested images caught the caustic crossing endpoint. This caustic endpoint data is critical to the conclusion that a planet is required.

4. Lightcurve OGLE alert

5. Definition of a Planet Formed by core accretion? (with a rocky core) –But we don’t know that this is how planets form! –We aren’t even sure about Jupiter’s rocky core! Secondary Mass < 13 M jupiter ? –This is the Deuterium burning threshold for solar metalicity, but why is that important? –What if binary is a 0.08 M  ? Mass ratio may only be 0.16! –In the brown dwarf desert Planetary mass fraction  < 0.03 –In the brown dwarf desert –Easily measured in a microlensing lightcurve!!

6. Lightcurve close-up & fit Cyan curve is the best fit single lens model –  2 = 651 Magenta curve is the best fit model w/ mass fraction   0.03 –  2 = 323 7 days inside caustic = 0.12 t E –Long for a planet, –but  mag = only 20-25% –as expected for a planet near the Einstein Ring

7. Caustic Structure & Magnification Pattern Blue and red dots indicate times of observations Parameters: t E = 61.6  1.8 days t 0 = 2848.06  0.13 MJD u min = 0.133  0.003 a p = 1.120  0.007  = 0.0039  0.007 q =  /(1+  )  = 223.8   1.4  t * = 0.059  0.007 days or  * /  E = 0.00096  0.00011

8. Alternative Models: a p < 1  2 = 110.4 t E = 75.3 days t 0 = 2850.64 MJD u min = 0.098 a p = 0.926  = 0.0117  = -6.1  t * = 0.036 days Also planetary!

9. Alternative Models: a p < 1  2 = 110.4 t E = 75.3 days t 0 = 2850.64 MJD u min = 0.098 a p = 0.926  = 0.0117  = -6.1  t * = 0.036 days Also planetary!

10. Alternative Models:  ~ 180   2 = 40.15 t E = 76.0 days t 0 = 2847.09 MJD u min = 0.100 a p = 1.064  = 0.0127  = 185.6  t * = 0.034 days Also planetary!

11. Alternative Models:  ~ 180   2 = 40.15 t E = 76.0 days t 0 = 2847.09 MJD u min = 0.100 a p = 1.064  = 0.0127  = 185.6  t * = 0.034 days Also planetary!

12. Alternative Models: Early 1 st Caustic Crossing  2 = 7.37 t E = 58.5 days t 0 = 2847.90 MJD u min = 0.140 a p = 1.121  = 0.0069  = 218.9  t * = 0.061 days Excluded by 2.7  Adjust  = 0.0039  0.007 to  = 0.0039  0.011

13. Lens Star Constraints Using I source = 19.7 and V-I = 1.58,we conclude that the source is a bulge G dwarf of radius:  * = 520  80  as I blend = 20.7  0.4 Gives likelihood curve

14. Planetary Parameters in Physical Units Best fit lens distance = 5.2 kpc –90% c.l. range is 2.3-5.4 kpc Best fit separation = 3.0 AU –90% c.l. range is 1.3-3.1 AU Best fit stellar mass = 0.36 M  –90% c.l. range is 0.08-0.39 M  Best fit planet mass = 1.5 M jup –90% c.l. range is 0.3-1.6 M jup If lens star is a 0.6 M  white dwarf –D lens = 6.1 kpc –a p = 1.8 AU –M p = 2.5 M jup

15. Conclusions 1 st definitive  lensing planetary discovery - complete coverage not required for characterization Real-time data monitoring was critical! S. Gaudi video