Bending of starlight by stars

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(Part II)
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Bending of starlight by stars (Gravitational
microlensing)
angular Einstein radius
with typical DS 8.5 kpc and DL 6.5 kpc
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Bending of starlight by stars (Gravitational
microlensing)
tE 40 (M/M?)1/2 days
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First reported microlensing event
Nature 365, 621 (October 1993)
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Current microlensing surveys (2007)
1.8m MOA Telescope, Mt John (New Zealand)
daily monitor ? 100 million stars,
t 10-6 for microlensing event ? 1000 events
alerted per year
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Planet detection by microlensing
adapted from M. Dominik et al. (PLANET
collaboration), 2000, PSS 50, 299
adapted from M. Dominik et al. (PLANET
collaboration), PSS 50, 299 (2002)
Text
Prediction from data prior to first caustic peak
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A round-the-clock follow-up network
http//planet.iap.fr
80 detected in A0 ? 10 events
PLANET restricted (1999) 3 fJ jupiters/year
MACHO/OGLE-II (1999) 100 alerts
PLANET full capability 15-25 fJ jupiters/year
OGLE-III/MOA (2006) 1000 alerts
M. Dominik et al. (PLANET collaboration) 2002,
PSS 50, 299
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PLANET planet detection efficiency
14 most favourable events from 2004 season
preferred
m large
a 1 4 AU
RS (few km) und D (few kpc) gives rE DL?E
(few AU)
preliminary
duration ?t and probability of signal q1/2
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First planetary abundance limits
from 42 events well-covered by PLANET 1995-1999
1/4
1/3
1/2
jupiter-mass
2/3
3/4
f gt f(d,q) ruled out at 95 C.L.
M. Albrow et al. (PLANET collaboration), 2001,
ApJ 556, L113
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Survey detection efficiency for planets
Cumulated planet detection efficiency
2002 OGLE-III data - 321 events
m mjup
q 10-3
q 10-4
C. Snodgrass, K. Horne, Y. Tsapras 2004, MNRAS,
351, 967
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The first microlensing planet
OGLE 2003-BLG-235 MOA 2003-BLG-53
M 1.5 M?
tE 61.5 d, d 1.12, q 3.9 10-3, t?
0.059 d ?? (0.50 /- 0.05) µas
I. A. Bond et al. (MOA and OGLE collaborations),
2004, ApJ 606, L155
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.... and the second one
OGLE 2005-BLG-071
close binary tE 73.9 d d 0.758 q 6.7
10-3 wide binary tE 70.9 d d 1.294 q 7.1
10-3
M 3 M?
A. Udalski et al. (OGLE, MicroFUN, MOA, and
PLANET/RoboNet collaborations), 2005, ApJ 628,
L109
Text
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From Jupiters to Earths
April 2004
Earth-like planet search to start
Dominik If 20 of these stars are surrounded by
planets, we expect to find 10-15 giant planets
and one or two Earth-sized worlds within three
years.
Text
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Host stars and expected planet abundance
Ida S., Lin D. N. C., 2005, ApJ 626, 1045
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OGLE 2005-BLG-390
True-colour image composed from BVI taken with
Danish 1.54m at ESO LaSilla (PLANET collaboration)
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OGLE 2005-BLG-390
Image taken with Danish 1.54m at ESO
LaSilla, convolved with model light curve
(animation by Daniel Kubas)
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OGLE 2005-BLG-390
31-Jul
10-Aug
J.-P. Beaulieu, D.P. Bennett, P. Fouqué, A.
Williams, M. Dominik, and 68 others
(PLANET/RoboNet, OGLE, and MOA
collaborations), 2006, Nature 439, 437
J.-P. Beaulieu et al. (PLANET/RoboNet, OGLE, and
MOA collaborations), 2006, Nature, in press
(26-Jan)
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OGLE-2005-BLG-390 magnification map
Einstein ring
source trajectory
map by Aarno Korpela, animation by Martin Dominik
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Mp 5.5 M? (2.1), M? 0.22 M? (2.1), a 2.9 AU
(1.6), P 10.4 yr (2.0), DL (0.85 0.15) RGC
J.-P. Beaulieu, D.P. Bennett, P. Fouqué, A.
Williams, M. Dominik, and 68 others, (PLANET/RoboN
et, OGLE, and MOA collaborations), 2006, Nature
439, 437
M. Dominik, 2006, MNRAS 367, 669
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Exoplanet discovery space
figure courtesy of K. Horne
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Approaching the habitable zone
http//www.ibiblio.org/astrobiology
(follows J. F. Kasting, D. P. Whitmire, R. T.
Reynolds, 1993, Icarus 101, 108)
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informal consortium, involving amateur
astronomers
only observe highly-promising close-alignment
events
M 13 M?
A. Gould et al., 2006, ApJ 644, L37
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Exoplanet discovery space (II)
figure courtesy of K. Horne
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Detections and planetary abundance
Average detection efficiency
14 prime events - PLANET 2004
Microlensing detections
A. Cassan, D. Kubas, M. Dominik et al. (PLANET
collaboration), in preparation
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RoboNet 1.0
http//www.astro.livjm.ac.uk
Common PLANET/RoboNet microlensing campaign since
2005
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5.5 M?
1 M?
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simulated data
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simulated data
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Planet with 0.1 Earth masses
d 1.2
tE 11.0 d
u0 0.359
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Microlensing live
continue
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Future projects (I)
Automated Robotic Terrestrial Exoplanet
MIcrolensing Search
A possible expert-system based cooperative effort
to hunt for planets of Earth mass and below
M. Dominik, K. Horne, A. Allan, N.J. Rattenbury,
Y. Tsapras, C. Snodgrass et al.
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Future projects (II)
GAlactic BAR Infrared Time-domain Survey (GABARIT)
A UKIRT Large Project Proposal
E. Kerins et al.
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Planets detected by microlensing ( )
2007
2008
2009
2010
2006