Gj 3236: A New Bright, Very Low Mass Eclipsing Binary System Discovered by the Mearth Observatory

Irwin, Jonathan; Charbonneau, David; Berta, Zachory K.; Quinn, Samuel N.; Latham, David W.; Torres, Guillermo; Blake, Cullen H.; Burke, Christopher J.; Esquerdo, Gilbert A.; Fürész, Gábor; Mink, Jessica; Nutzman, P.; Szentgyorgyi, Andrew; Calkins, M.; Falco, E.; Bloom, J.; Starr, D.

doi:10.1088/0004-637x/701/2/1436

Cited by 93 publications

(57 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Toward this goal, we encourage other researchers to publish Hα measurements for their targets, as this is usually readily available from the spectra used to determine radial velocities. Indeed, a number of low-mass EBs with accurate masses and radii have been published in the last few years (e.g., Vaccaro et al 2007;Irwin et al 2009Irwin et al , 2011Morales et al 2010;Kraus et al 2011;, potentially increasing by a factor of 2-3 the small sample that we have used from López- Morales (2007). We are currently collecting new Hα measurements for these published EBs that lack resolved Hα measurements in order to improve the empirical relations that we have presented here.…”

Section: Discussionmentioning

confidence: 98%

An Empirical Correction for Activity Effects on the Temperatures, Radii, and Estimated Masses of Low-Mass Stars and Brown Dwarfs

Stassun

Kratter

Scholz

et al. 2012

ApJ

102

143

View full text Add to dashboard Cite

We present empirical relations for determining the amount by which the effective temperatures and radii-and therefore the estimated masses-of low-mass stars and brown dwarfs are altered due to chromospheric activity. We base our relations on a large set of low-mass stars in the field with Hα activity measurements, and on a set of low-mass eclipsing binaries with X-ray activity measurements from which we indirectly infer the Hα activity. Both samples yield consistent relations linking the amount by which an active object's temperature is suppressed, and its radius inflated, to the strength of its Hα emission. These relations are found to approximately preserve bolometric luminosity. We apply these relations to the peculiar brown dwarf eclipsing binary 2M0535−05, in which the active, higher-mass brown dwarf has a cooler temperature than its inactive, lower-mass companion. The relations correctly reproduce the observed temperatures and radii of 2M0535−05 after accounting for the Hα emission; 2M0535−05 would be in precise agreement with theoretical isochrones were it is inactive. The relations that we present are applicable to brown dwarfs and low-mass stars with masses below 0.8 M and for which the activity, as measured by the fractional Hα luminosity, is in the range −4.6 log L Hα /L bol −3.3. We expect these relations to be most useful for correcting radius and mass estimates of low-mass stars and brown dwarfs over their active lifetimes (few Gyr) and when the ages or distances (and therefore luminosities) are unknown. We also discuss the implications of this work for improved determinations of young cluster initial mass functions.

show abstract

Section: Discussionmentioning

confidence: 98%

An Empirical Correction for Activity Effects on the Temperatures, Radii, and Estimated Masses of Low-Mass Stars and Brown Dwarfs

Stassun

Kratter

Scholz

et al. 2012

ApJ

102

143

View full text Add to dashboard Cite

show abstract

“…The findings presented herein are the result of more than 15 years of high-precision Doppler monitoring of nearby stars. Additional information will soon pour in from other surveys using techniques such as microlensing (e.g., Dong et al 2009;Gould et al 2010), astrometry (Boss et al 2009), transits (Borucki et al 2004;Barge et al 2008;Irwin et al 2009), and direct imaging (Claudi et al 2006;Artigau et al 2008;Macintosh et al 2008).…”

Section: Summary and Discussionmentioning

confidence: 99%

Giant Planet Occurrence in the Stellar Mass-Metallicity Plane

Johnson¹,

Aller²,

Howard³

et al. 2010

PUBL ASTRON SOC PAC

769

824

View full text Add to dashboard Cite

ABSTRACT. Correlations between stellar properties and the occurrence rate of exoplanets can be used to inform the target selection of future planet-search efforts and provide valuable clues about the planet-formation process. We analyze a sample of 1266 stars drawn from the California Planet Survey targets to determine the empirical functional form describing the likelihood of a star harboring a giant planet as a function of its mass and metallicity. Our stellar sample ranges from M dwarfs with masses as low as 0:2 M ⊙ to intermediate-mass subgiants with masses as high as 1:9 M ⊙ . In agreement with previous studies, our sample exhibits a planet-metallicity correlation at all stellar masses; the fraction of stars that harbor giant planets scales as f ∝ 10 1:2½Fe=H . We can rule out a flat metallicity relationship among our evolved stars (at 98% confidence), which argues that the high metallicities of stars with planets is not likely due to convective envelope "pollution." Our data also rule out a constant planet occurrence rate for ½Fe=H < 0, indicating that giant planets continue to become rarer at sub-Solar metallicities. We also find that planet occurrence increases with stellar mass (f ∝ M ⋆ ), characterized by a rise from 3% around M dwarfs (0:5 M ⊙ ) to 14% around A stars (2 M ⊙ ), at Solar metallicity. We argue that the correlation between stellar properties and giant planet occurrence is strong supporting evidence of the core-accretion model of planet formation.

show abstract

“…In that work, we found that all period-phased MEarth candidates above a transit depth signal to noise of D/σ MarPLE > 7.5 were either catastrophic instrumental problems, obvious stellar variability artifacts, or bona fide eclipsing systems Irwin et al 2009Irwin et al , 2010Irwin et al , 2011b. GJ1214b was identified in 2009 before the development of the full MISS MarPLE framework, using the box-fitting least squares search algorithm (Kovács et al 2002) and pre-cleaning with an iterative median filter (Aigrain & Irwin 2004) and trend filtering algorithm (Kovács et al 2005).…”

Section: Transit Detection Efficienciesmentioning

confidence: 99%

Constraints on Planet Occurrence Around Nearby Mid-to-Late M Dwarfs From the Mearth Project

Berta

Irwin

Charbonneau

2013

ApJ

Self Cite

View full text Add to dashboard Cite

The MEarth Project is a ground-based photometric survey intended to find planets transiting the closest and smallest main-sequence stars. In its first four years, MEarth discovered one transiting exoplanet, the 2.7 R ⊕ planet GJ1214b. Here, we answer an outstanding question: in light of the bounty of small planets transiting small stars uncovered by the Kepler mission, should MEarth have found more than just one planet so far? We estimate MEarth's ensemble sensitivity to exoplanets by performing end-to-end simulations of 1.25 × 10 6 observations of 988 nearby mid-tolate M dwarfs, gathered by MEarth between 2008 October and 2012 June. For 2-4 R ⊕ planets, we compare this sensitivity to results from Kepler and find that MEarth should have found planets at a rate of 0.05-0.36 planets yr −1 in its first four years. As part of this analysis, we provide new analytic fits to the Kepler early M dwarf planet occurrence distribution. When extrapolating between Kepler's early M dwarfs and MEarth's mid-to-late M dwarfs, we find that assuming the planet occurrence distribution stays fixed with respect to planetary equilibrium temperature provides a good match to our detection of a planet with GJ1214b's observed properties. For larger planets, we find that the warm (600-700 K), Neptune-sized (4 R ⊕ ) exoplanets that transit early M dwarfs like Gl436 and GJ3470 occur at a rate of <0.15 star −1 (at 95% confidence) around MEarth's later M dwarf targets. We describe a strategy with which MEarth can increase its expected planet yield by 2.5 × without new telescopes by shifting its sensitivity toward the smaller and cooler exoplanets that Kepler has demonstrated to be abundant.

show abstract

Gj 3236: A New Bright, Very Low Mass Eclipsing Binary System Discovered by the Mearth Observatory

Cited by 93 publications

References 56 publications

An Empirical Correction for Activity Effects on the Temperatures, Radii, and Estimated Masses of Low-Mass Stars and Brown Dwarfs

An Empirical Correction for Activity Effects on the Temperatures, Radii, and Estimated Masses of Low-Mass Stars and Brown Dwarfs

Giant Planet Occurrence in the Stellar Mass-Metallicity Plane

Constraints on Planet Occurrence Around Nearby Mid-to-Late M Dwarfs From the Mearth Project

Contact Info

Product

Resources

About