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The first Neptune analog or super-earth with a Neptune-like orbit : MOA-2013-BLG-605LB

Sumi, T.; Udalski, A.; Bennett, D. P.; Gould, A.; Poleski, R.; Bond, I. A.; Skowron, J.; Rattenbury, N.; Pogge, R. W. and Bensby, T. LU , et al. (2016) In Astrophysical Journal 825(2).
Abstract

We present the discovery of the first Neptune analog exoplanet or super-Earth with a Neptune-like orbit, MOA-2013-BLG-605Lb. This planet has a mass similar to that of Neptune or a super-Earth and it orbits at 9 ∼ 14 times the expected position of the snow line, a snow, which is similar to Neptune's separation of 11 a snow from the Sun. The planet/host-star mass ratio is q = (3.6 ± 0.7) × 10-4 and the projected separation normalized by the Einstein radius is s = 2.39 ± 0.05. There are three degenerate physical solutions and two of these are due to a new type of degeneracy in the microlensing parallax parameters, which we designate "the wide degeneracy." The three models have (i) a Neptune-mass planet with... (More)

We present the discovery of the first Neptune analog exoplanet or super-Earth with a Neptune-like orbit, MOA-2013-BLG-605Lb. This planet has a mass similar to that of Neptune or a super-Earth and it orbits at 9 ∼ 14 times the expected position of the snow line, a snow, which is similar to Neptune's separation of 11 a snow from the Sun. The planet/host-star mass ratio is q = (3.6 ± 0.7) × 10-4 and the projected separation normalized by the Einstein radius is s = 2.39 ± 0.05. There are three degenerate physical solutions and two of these are due to a new type of degeneracy in the microlensing parallax parameters, which we designate "the wide degeneracy." The three models have (i) a Neptune-mass planet with a mass of Mp = 21-7 +6M orbiting a low-mass M-dwarf with a mass of Mh = 0.19-0.06 +0.05M, (ii) a mini-Neptune with Mp = 7.9-1.2 +1.8M orbiting a brown dwarf host with Mh = 0.068-0.011 +0.019M, and (iii) a super-Earth with Mp = 3.2-0.3 +0.5MM orbiting a low-mass brown dwarf host with Mh = 0.025-0.0004 +0.005M, which is slightly favored. The 3D planet-host separations are 4.6-1.2 +4.7au, 2.1-0.2 +1.0au, and 0.94-0.02 +0.67au, which are 8.9-1.4 +10.5, 12-1 +7, or 14-1 +11 times larger than a snow for these models, respectively. Keck adaptive optics observations confirm that the lens is faint. This discovery suggests that low-mass planets with Neptune-like orbits are common. Therefore processes similar to the one that formed Neptune in our own solar system or cold super-Earths may be common in other solar systems.

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@misc{081ead21-22a7-4415-b6be-67efd47d2fba,
  abstract     = {<p>We present the discovery of the first Neptune analog exoplanet or super-Earth with a Neptune-like orbit, MOA-2013-BLG-605Lb. This planet has a mass similar to that of Neptune or a super-Earth and it orbits at 9 ∼ 14 times the expected position of the snow line, a <sub>snow</sub>, which is similar to Neptune's separation of 11 a <sub>snow</sub> from the Sun. The planet/host-star mass ratio is q = (3.6 ± 0.7) × 10<sup>-4</sup> and the projected separation normalized by the Einstein radius is s = 2.39 ± 0.05. There are three degenerate physical solutions and two of these are due to a new type of degeneracy in the microlensing parallax parameters, which we designate "the wide degeneracy." The three models have (i) a Neptune-mass planet with a mass of M<sub>p</sub> = 21<sub>-7</sub> <sup>+6</sup>M<sub>⊕</sub> orbiting a low-mass M-dwarf with a mass of M<sub>h</sub> = 0.19<sub>-0.06</sub> <sup>+0.05</sup>M<sub>⊙</sub>, (ii) a mini-Neptune with M<sub>p</sub> = 7.9<sub>-1.2</sub> <sup>+1.8</sup>M<sub>⊕</sub> orbiting a brown dwarf host with M<sub>h</sub> = 0.068<sub>-0.011</sub> <sup>+0.019</sup>M<sub>⊙</sub>, and (iii) a super-Earth with M<sub>p</sub> = 3.2<sub>-0.3</sub> <sup>+0.5</sup>MM<sub>⊕</sub> orbiting a low-mass brown dwarf host with M<sub>h</sub> = 0.025<sub>-0.0004</sub> <sup>+0.005</sup>M<sub>⊙</sub>, which is slightly favored. The 3D planet-host separations are 4.6<sub>-1.2</sub> <sup>+4.7</sup>au, 2.1<sub>-0.2</sub> <sup>+1.0</sup>au, and 0.94<sub>-0.02</sub> <sup>+0.67</sup>au, which are 8.9<sub>-1.4</sub> <sup>+10.5</sup>, 12<sub>-1</sub> <sup>+7</sup>, or 14<sup>-1</sup> <sup>+11</sup> times larger than a <sub>snow</sub> for these models, respectively. Keck adaptive optics observations confirm that the lens is faint. This discovery suggests that low-mass planets with Neptune-like orbits are common. Therefore processes similar to the one that formed Neptune in our own solar system or cold super-Earths may be common in other solar systems.</p>},
  author       = {Sumi, T. and Udalski, A. and Bennett, D. P. and Gould, A. and Poleski, R. and Bond, I. A. and Skowron, J. and Rattenbury, N. and Pogge, R. W. and Bensby, T. and Beaulieu, J. P. and Marquette, J. B. and Batista, V. and Brillant, S. and Abe, F. and Asakura, Y. and Bhattacharya, A. and Donachie, M. and Freeman, M. and Fukui, A. and Hirao, Y. and Itow, Y. and Koshimoto, N. and Li, M. C A and Ling, C. H. and Masuda, K. and Matsubara, Y. and Muraki, Y. and Nagakane, M. and Ohnishi, K. and Oyokawa, H. and Saito, To and Sharan, A. and Sullivan, D. J. and Suzuki, D. and Tristram, P. J. and Yonehara, A. and Szymański, M. K. and Ulaczyk, K. and Kozłowski, S. and Wyrzykowski,  and Kubiak, M. and Pietrukowicz, P. and Pietrzyński, G. and Soszyński, I. and Han, C. and Jung, Y. K. and Shin, I. G. and Lee, C. U.},
  issn         = {0004-637X},
  keyword      = {Galaxy: bulge,gravitational lensing: micro,planetary systems},
  language     = {eng},
  month        = {07},
  number       = {2},
  publisher    = {ARRAY(0xb780920)},
  series       = {Astrophysical Journal},
  title        = {The first Neptune analog or super-earth with a Neptune-like orbit : MOA-2013-BLG-605LB},
  url          = {http://dx.doi.org/10.3847/0004-637X/825/2/112},
  volume       = {825},
  year         = {2016},
}