@article{ff3604becf4a4beaba1b58d48a9122a1,
title = "Microlens Ogle-2005-BLG-169 implies that cool neptune-like planets are common",
abstract = " We detect a Neptune mass ratio (q 8 #10 5 ) planetary companion to the lens star in the extremely high magnification (A ∼ 800) microlensing event OGLE-2005-BLG-169. If the parent is a main-sequence star, it has mass M ∼ 0.5 M,, implying a planet mass of ∼13 M and projected separation of ∼2.7 AU. When intensely monitored over their peak, high-magnification events similar to OGLE-2005-BLG-169 have nearly complete sensitivity to Neptune mass ratio planets with projected separations of 0.6–1.6 Einstein radii, corresponding to 1.6–4.3 AU in the present case. Only two other such events were monitored well enough to detect Neptunes, and so this detection by itself suggests that Neptune mass ratio planets are common. Moreover, another Neptune was recently discovered at a similar distance from its parent star in a low-magnification event, which are more common but are individually much less sensitive to planets. Combining the two detections yields 90% upper and lower frequency limits f p 0.38 0.31 0.22 over just 0.4 decades of planet-star separation. In particular, f 1 16% at 90% confidence. The parent star hosts no Jupiter-mass companions with projected separations within a factor 5 of that of the detected planet. The lens-source relative proper motion is m ∼ 7–10 mas yr 1 , implying that if the lens is sufficiently bright, I 23.8, it will be detectable by the Hubble Space Telescope by 3 years after peak. This would permit a more precise estimate of the lens mass and distance and, so, the mass and projected separation of the planet. Analogs of OGLE-2005-BLG-169Lb orbiting nearby stars would be difficult to detect by other methods of planet detection, including radial velocities, transits, and astrometry.",
keywords = "Galaxy: bulge, Gravitational lensing, Planetary systems",
author = "A. Gould and A. Udalski and D. An and Bennett, {D. P.} and Zhou, {A. Y.} and S. Dong and Rattenbury, {N. J.} and Gaudi, {B. S.} and Yock, {P. C.M.} and Bond, {I. A.} and Christie, {G. W.} and K. Horne and J. Anderson and Stanek, {K. Z.} and DePoy, {D. L.} and C. Han and J. McCormick and Park, {B. G.} and Pogge, {R. W.} and Poindexter, {S. D.} and I. Soszy{\'n}ski and Szyma{\'n}ski, {M. K.} and M. Kubiak and G. Pietrzy{\'n}ski and O. Szewczyk and Wyrzykowski and K. Ulaczyk and B. Paczy{\'n}ski and Bramich, {D. M.} and C. Snodgrass and Steele, {I. A.} and Burgdorf, {M. J.} and Bode, {M. F.} and Botzler, {C. S.} and S. Mao and Swaving, {S. C.}",
note = "Funding Information: We acknowledge the following support: NSF AST 04-52758 (A. G., S. D.); NASA NNG04GL51G (D. L. D., A. G., R. W. P.); Polish MEiN 2P03D02124, NSF AST 02-04908, NASA grant NAG 5-12212 (OGLE); Polish FNP SP13/2003 (A. U.); NSF AST 02-06189, NASA NAF 5-13042 (D. P. B.); NSF AST 03-07480 (A.-Y. Z.); Menzel Fellowship, Harvard College Observatory (B. S. G.); SRC Korea Science and Engineering Foundation (C. H.); the Korea Astronomy and Space Science Institute (B.-G. P.); Mars-den Fund of New Zealand (I. A. B., P. C. M. Y.); the Deutsche Forschungsgemeinschaft (C. S. B.); PPARC, EU FP6 program “ANGLES” ({\L}. W., S. M., N. J. R.); PPARC (RoboNet); and the Dill Faulkes Educational Trust (Faulkes Telescope North). Assistance by Lydia Philpott, Jan Snigula, and the computer science department of the University of Auckland is acknowledged. We thank the MDM staff for their support. All findings are those of the authors and do not necessarily reflect NSF views. Publisher Copyright: {\textcopyright} 2006. The American Astronomical Society. All rights reserved.",
year = "2006",
month = jun,
day = "10",
doi = "10.1086/505421",
language = "English",
volume = "644",
pages = "L37--L40",
journal = "Astrophysical Journal Letters",
issn = "2041-8205",
publisher = "American Astronomical Society",
number = "1",
}