MOA-2010-BLG-328Lb: A sub-Neptune orbiting very late M dwarf?

Journal Article · Fri Dec 20 00:00:00 EST 2013 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/779/2/91· OSTI ID:22348474

Furusawa, K.; Abe, F.; Itow, Y.; Masuda, K.; Matsubara, Y. ^[1]; Udalski, A. ^[2]; Sumi, T. ^[3]; Bennett, D. P. ^[4]; Bond, I. A.; Ling, C. H. ^[5]; Gould, A. ^[6]; Jørgensen, U. G. ^[7]; Snodgrass, C. ^[8]; Prester, D. Dominis ^[9]; Albrow, M. D. ^[10]; Botzler, C. S.; Freeman, M. ^[11]; Chote, P.; Harris, P. ^[12]; Consortium, MiNDSTEp ; others, and

---

1. Solar-Terrestrial Environment Laboratory, Nagoya University, Nagoya 464-8601 (Japan)
2. Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland)
3. Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka 560-0043 (Japan)
4. Department of Physics, 225 Nieuwland Science Hall, University of Notre Dame, Notre Dame, IN 46556 (United States)
5. Institute for Information and Mathematical Sciences, Massey University, Private Bag 102-904, Auckland 1330 (New Zealand)
6. Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States)
7. Niels Bohr Institutet, Københavns Universitet, Juliane Maries Vej 30, 2100 Copenhagen (Denmark)
8. Max Planck Institute for Solar System Research, Max-Planck-Str. 2, D-37191 Katlenburg-Lindau (Germany)
9. Department of Physics, University of Rijeka, Omladinska 14, 51000 Rijeka (Croatia)
10. Department of Physics and Astronomy, University of Canterbury, Private Bag 4800, Christchurch 8020 (New Zealand)
11. Department of Physics, University of Auckland, Private Bag 92-019, Auckland 1001 (New Zealand)
12. School of Chemical and Physical Sciences, Victoria University, Wellington (New Zealand)

We analyze the planetary microlensing event MOA-2010-BLG-328. The best fit yields host and planetary masses of M {sub h} = 0.11 ± 0.01 M {sub ☉} and M {sub p} = 9.2 ± 2.2 M {sub ⊕}, corresponding to a very late M dwarf and sub-Neptune-mass planet, respectively. The system lies at D {sub L} = 0.81 ± 0.10 kpc with projected separation r = 0.92 ± 0.16 AU. Because of the host's a priori unlikely close distance, as well as the unusual nature of the system, we consider the possibility that the microlens parallax signal, which determines the host mass and distance, is actually due to xallarap (source orbital motion) that is being misinterpreted as parallax. We show a result that favors the parallax solution, even given its close host distance. We show that future high-resolution astrometric measurements could decisively resolve the remaining ambiguity of these solutions.

• OSTI ID: 22348474
• Journal Information: Astrophysical Journal, Vol. 779, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
DWARF STARS
GRAVITATIONAL LENSES
MASS
MATHEMATICAL SOLUTIONS
NEPTUNE PLANET
RESOLUTION