1. Cool planet mass function and a fly’s-eye ‘evryscope’ at Antarctica Philip Yock, Auckland, New Zealand 20th Microlensing Workshop Institut d'Astrophysique de Paris 13-15 January 2016

2. Twenty years ago Meeting at IAP on gravitational microlensing Christophe Alard announced DIA Bohdan Paczynski was present Would be pleased with results on planets Pleased with contributions by amateurs

3. Plea for high magnification In the days of Spitzer, K2 and KMTNet Hope that high mag events still followed

4. The mass function PLANET, Cassan et al, Nature 48, 167, 2012 OGLE-MOA-WISE Oct 2015 preprint MOA Paris, Jan 2016

5. The mass function PLANET, Cassan et al, Nature 48, 167, 2012 Need more data at low masses OGLE-MOA-WISE Oct 2015 preprint MOA This meeting

6. Few detections and low efficiencies at low mass OGLE-MOA-Wise (four years) MOA (6 years ) Single detections Nil detections

7. KMTNet in 2016 Calen Henderson et al, ApJ 794, 52, 2014 Assumes saturated Cassan mass function KMTNet will detect about 8 low- mass (1 – 10 M E ) planets per year

8. High magnification technique? μFUN technique with 1-2m class telescopes Monitor FWHM continuously if A max > 50 Approximately 24 hours per event Approximately 20 events per year

9. Reminder: monitor Full Width at Half Max FWHM ~ 1 day

10. Follow-up telescopes ignore the wings FWHM ~ 1 day Ignore

11. 1.5 Earth mass Photometric errors and cadence from the MOA telescope FWHM

12. 5.5 Earth masses

13. Detection efficiency u 0 : 6 values ±.02, ±.01, ±.005 t E : 3 values 10 days, 20 days, 30 days ρ : 3 values.0005,.001,.002 q : 5 values 1.5, 2.5, 3.5, 4.5, 5.5 × 10 -5 s : 5 values.95,.85,.75,.65,.55 α : 1 value 60⁰ (for 30⁰ < α < 90⁰) Follow-up data: 1 measurement every.001 day in FWHM at MOA cadence and precision in fair weather Found fraction of events with Δχ 2 > 300 F. Abe et al MNRAS 431, 2975, 2013 C. Airey, Doha workshop, 2013 L. Philpott, Santa Barbara, 2014

14. Detection efficiencies Planet mass q = 5 × 10 -5 Planet distance 0.6 < s < 1.7 Planet angle 30⁰ < α < 150⁰ or 210⁰ < α < 330⁰ Detection efficiency ̴ 75% Planet mass q = 2 × 10 -5 Planet distance 0.8 < s < 1.25 Planet angle 30⁰ < α < 150⁰ or 210⁰ < α < 330⁰ Detection efficiency ̴ 80%

15. Detection rate Assume Cassan mass function Assume 20 events monitored per year with A max > 50 Detetct 8 low mass planets (1-6M E ) per year Comparable to KMTNet Independent sample of events Could have been done already

16. Examples: first two high mag planets OGLE-2005-BLG-071 q = 0.0071 s = 1.29 OGLE-2005-BLG-169 q = 6 × 10 -5 s = 1.02

17. Recent event – OGLE-2015-BLG-0966 Rachel Street et al, arXiv:1508.0702

18. FWHM (top 0.75 mag)

19. FWHM 2.2days modelling? systematics? moon?

20. Eyeball measurements α and ρ tWtW t0t0 tptp source track lens axis α α = tan -1 t E u min /(t p -t 0 ) = 50⁰ t W ≈ 3ρt E (Abe et al) ≈ 0.24 day ρ ≈ 0.24/3×58 ≈ 0.0014

21. Final measurements of s, q, α, ρ tWtW t0t0 tptp source track lens axis α α = tan -1 t E u min /(t p -t 0 ) = 50⁰ t W ≈ 3ρt E ≈ 0.24 day ρ ≈ 0.24/3×58 ≈ 0.0014 The values of s and q cannot be eyeballed. The shape of the planetary perturbation yielded s = 1.115 or 0.909 and q = 1.7 × 10 -4

22. OGLE-2015-BLG-0966

23. Low mass planets can be found at high mag ?

24. Multiple planets?

25. Two planet test ̶ OGLE-2012-BLG-0026 Han et al, ApJ 762, L28 (2013) Follow-up observations by amateurs

26. OGLE-2012-BLG-0026 Magnification maps, or whatever

27. OGLE-2012-BLG-0026 Above are Jovian planets Neptunes more common Multi-Neptunes?

28. Triple-Neptune system found by RV Angelle Tanner et al, ApJ 800, 115 (2015) H unt by microlensing

29. Summary High mag technique sensitive to low-mass planets Provides a “snapshot” of a planetary system near the Einstein ring Multi-planets detectable Statistics ok No problems with low detection efficiencies Statistically unbiased and independent sample of events

30. Telescopes OGLE and MOA survey more than 30 square deg Continuous follow-up needed Hopefully follow-up telescopes available in Australia (Tasmania), South Africa (SAAO) and Chile (Danish) Some overlap between KMTNet and OGLE/MOA fields would provide checks

31. Antarctica – a personal dream for NZ Excellent seeing, dry atmosphere, long nights, constant air mass

32. Antarctica – a personal dream for NZ SP F A C USA, Australia, Japan, China, France there, but only one NZer

33. Matthew Freeman at Ridge A in 2015 80⁰S, 4000m, driest & coldest place on Earth

34. One possibility – the ‘evryscope’ 25 telephoto lenses (200mm) 10,000 square degree FOV Comparable to TESS Seek transited M dwarfs within 100 lt yr Microlensing events at < 1 kpc (r E ~ 1 AU) Further information: A. Fukui et al ApJ 670, 423 (2007) S. Gaudi et al ApJ 677, 1268 (2008) N. Law et al PASP 127, 234 (2015) Chilean Evryscope (Nick Law et al)

35. Estimated event rate No. of sources = 4/3π (1000pc 3 – 700pc 3 ) × 0.01pc -3 = 28 million Lenses per source = πAU 2 × 500pc × 0.1 pc -3 = 4 x10 -9 Prob of lensing = 0.12 Event duration = 7 days Events in 10,000 square degree per winter = 0.12 × 365/7 × 1/4 × 1/2 = 1 per winter Probably too few to hunt for planets F,G K,M