LSPM J1112+7626: DETECTION OF A 41 DAY M-DWARF ECLIPSING BINARY FROM THE MEARTH TRANSIT SURVEY

Journal Article · Thu Dec 01 00:00:00 EST 2011 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/742/2/123· OSTI ID:22004595

Irwin, Jonathan M; Quinn, Samuel N; Berta, Zachory K; Latham, David W; Torres, Guillermo; Burke, Christopher J; Charbonneau, David; Dittmann, Jason; Esquerdo, Gilbert A; Stefanik, Robert P ^[1]; Oksanen, Arto ^[2]; Buchhave, Lars A ^[3]; Nutzman, Philip ^[4]; Berlind, Perry; Calkins, Michael L

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1. Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States)
2. Hankasalmi Observatory, Jyvaeskylaen Sirius ry, Vertaalantie 419, FI-40270 Palokka (Finland)
3. Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen (Denmark)
4. Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States)

We report the detection of eclipses in LSPM J1112+7626, which we find to be a moderately bright (I{sub C} = 12.14 {+-} 0.05) very low mass binary system with an orbital period of 41.03236 {+-} 0.00002 days, and component masses M{sub 1} = 0.395 {+-} 0.002 M{sub Sun} and M{sub 2} = 0.275 {+-} 0.001 M{sub Sun} in an eccentric (e = 0.239 {+-} 0.002) orbit. A 65 day out-of-eclipse modulation of approximately 2% peak-to-peak amplitude is seen in I-band, which is probably due to rotational modulation of photospheric spots on one of the binary components. This paper presents the discovery and characterization of the object, including radial velocities sufficient to determine both component masses to better than 1% precision, and a photometric solution. We find that the sum of the component radii, which is much better determined than the individual radii, is inflated by 3.8{sup +0.9}{sub -0.5}% compared to the theoretical model predictions, depending on the age and metallicity assumed. These results demonstrate that the difficulties in reproducing observed M-dwarf eclipsing binary radii with theoretical models are not confined to systems with very short orbital periods. This object promises to be a fruitful testing ground for the hypothesized link between inflated radii in M-dwarfs and activity.

• OSTI ID: 22004595
• Journal Information: Astrophysical Journal, Vol. 742, 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
ASTROPHYSICS
ECLIPSE
ORBITS
RADIAL VELOCITY
STARS