J-band variability of M dwarfs in the WFCAM Transit Survey

Goulding, N.; Barnes, John; Pinfield, D. J.; Kovács, G.; Birkby, Jayne; Hodgkin, S. T.; Catalán, S.; Sipőcz, Brigitta; Jones, H. R. A.; Burgo, C. del; Jeffers, S. V.; Nefs, S. V.; Gálvez-Ortiz, M. C.; Martín, E. L.

doi:10.1111/j.1365-2966.2012.21932.x

Cited by 52 publications

(24 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Indeed, archival sky surveys in the Vizier database indicate R-band magnitude variations of ≈1 mag for FW Tau AB. Photometric variability from stellar flares and star spots is minimal in the near-infrared (e.g., Tofflemire et al 2011;Davenport et al 2012;Goulding et al 2012). Accretion flows, hot spots, extinction variations, and disk heating can result in strong NIR variability (Skrutskie et al 1996;Carpenter et al 2001;Eiroa et al 2002;Rice et al 2012), but these effects are irrelevant for the Class III primary FW Tau AB (Rebull et al 2010).…”

Section: Nir Continuum Spectrummentioning

confidence: 99%

Spectroscopic Confirmation of Young Planetary-Mass Companions on Wide Orbits

Bowler

Liu

Kraus

et al. 2014

ApJ

101

110

View full text Add to dashboard Cite

We present moderate-resolution (R ∼ 4000-5000) near-infrared integral field spectroscopy of the young (1-5 Myr) 6-14 M Jup companions ROXs 42B b and FW Tau b obtained with Keck/OSIRIS and Gemini-North/NIFS. The spectrum of ROXs 42B b exhibits clear signs of low surface gravity common to young L dwarfs, confirming its extreme youth, cool temperature, and low mass. Overall, it closely resembles the free-floating 4-7 M Jup L-type Taurus member 2MASS J04373705+2331080. The companion to FW Tau AB is more enigmatic. Our optical and near-infrared spectra show strong evidence of outflow activity and disk accretion in the form of line emission from, Paβ, and H 2 . The molecular hydrogen emission is spatially resolved as a single lobe that stretches ≈0. 1 (15 AU). Although the extended emission is not kinematically resolved in our data, its morphology resembles shock-excited H 2 jets primarily seen in young Class 0 and Class I sources. The near-infrared continuum of FW Tau b is mostly flat and lacks the deep absorption features expected for a cool, late-type object. This may be a result of accretion-induced veiling, especially in light of its strong and sustained Hα emission (EW(Hα) 290 Å). Alternatively, FW Tau b may be a slightly warmer (M5-M8) accreting low-mass star or brown dwarf (0.03-0.15 M ) with an edge-on disk. Regardless, its young evolutionary stage is in stark contrast to its Class III host FW Tau AB, indicating a more rapid disk clearing timescale for the host binary system than for its wide companion. Finally, we present near-infrared spectra of the young (∼2-10 Myr) low-mass (12-15 M Jup ) companions GSC 6214-210 B and SR 12 C and find they best resemble low-gravity M9.5 and M9 substellar templates.

show abstract

Section: Nir Continuum Spectrummentioning

confidence: 99%

Spectroscopic Confirmation of Young Planetary-Mass Companions on Wide Orbits

Bowler

Liu

Kraus

et al. 2014

ApJ

101

110

View full text Add to dashboard Cite

show abstract

“…Stellar flares in light curves can potentially complicate the search for transits, and have even been observed during transit events themselves (Kundurthy et al, 2011). However, studies of M dwarf photometric variability on the timescales of transits conclude that stellar activity should not meaningfully affect the detection of exoplanets (Tofflemire et al, 2012;Goulding et al, 2012) (though they caution that this depends upon photometric filter and spectral type).…”

Section: Planet Detectabilitymentioning

confidence: 99%

The habitability of planets orbiting M-dwarf stars

2016

View full text Add to dashboard Cite

The prospects for the habitability of M-dwarf planets have long been debated, due to key differences between the unique stellar and planetary environments around these low-mass stars, as compared to hotter, more luminous Sunlike stars. Over the past decade, significant progress has been made by both space-and ground-based observatories to measure the likelihood of small planets to orbit in the habitable zones of M-dwarf stars. We now know that most M dwarfs are hosts to closely-packed planetary systems characterized by a paucity of Jupiter-mass planets and the presence of multiple rocky planets, with roughly a third of these rocky M-dwarf planets orbiting within the habitable zone, where they have the potential to support liquid water on their surfaces. Theoretical studies have also quantified the effect on climate and habitability of the interaction between the spectral energy distribution of M-dwarf stars and the atmospheres and surfaces of their planets. These and other recent results fill in knowledge gaps that existed at the time of the previous overview papers published nearly a decade ago by Tarter et al. (2007) and Scalo et al. (2007). In this review we provide a comprehensive picture of the current knowledge of M-dwarf planet occurrence and habitability based on work done in this area over the past decade, and summarize future directions planned in this quickly evolving field.

show abstract

“…Observations of field M dwarfs are therefore particularly important for constraining their angular momentum evolution. Substantial observational progress has been made in recent years, with many new measurements of rotation periods for field M dwarfs, notably by Kiraga & Stȩpień (2007, Norton et al (2007), Hartman et al (2011), Irwin et al (2011), Kiraga (2012), Goulding et al (2013), and McQuillan et al (2013).…”

Section: Introductionmentioning

confidence: 99%

The Rotation and Galactic Kinematics of Mid M Dwarfs in the Solar Neighborhood

Newton

Irwin

Charbonneau

et al. 2016

ApJ

264

417

View full text Add to dashboard Cite

Rotation is a directly observable stellar property, and it drives magnetic field generation and activity through a magnetic dynamo. Main-sequence stars with masses below approximately 0.35  M (mid-to-late M dwarfs) are fully convective, and are expected to have a different type of dynamo mechanism than solar-type stars. Measurements of their rotation rates provide insight into these mechanisms, but few rotation periods are available for these stars at field ages. Using photometry from the MEarth Project, we measure rotation periods for 387 nearby, mid-to-late M dwarfs in the northern hemisphere, finding periods from 0.1 to 140 days. The typical rotator has stable, sinusoidal photometric modulations at a semi-amplitude of 0.5%-1%. We find no period-amplitude relation for stars below 0.25  M and an anticorrelation between period and amplitude for higher-mass M dwarfs. We highlight the existence of older, slowly rotating stars without Hα emission that nevertheless have strong photometric variability. We use parallaxes, proper motions, radial velocities, photometry, and near-infrared metallicity estimates to further characterize the population of rotators. The Galactic kinematics of our sample is consistent with the local population of G and K dwarfs, and rotators have metallicities characteristic of the solar neighborhood. We use the W space velocities and established age-velocity relations to estimate that stars with P<10 days have ages of on average <2 Gyr, and that those with P>70 days have ages of about 5 Gyr. The period distribution is dependent on mass: as the mass decreases, the slowest rotators at a given mass have longer periods, and the fastest rotators have shorter periods. We find a lack of stars with intermediate rotation periods, and the gap between the fast and slow rotators is larger for lower masses. Our data are consistent with a scenario in which these stars maintain rapid rotation for several gigayears, then spin down quickly, reaching periods of around 100 days by a typical age of 5 Gyr.

show abstract

J-band variability of M dwarfs in the WFCAM Transit Survey

Cited by 52 publications

References 50 publications

Spectroscopic Confirmation of Young Planetary-Mass Companions on Wide Orbits

Spectroscopic Confirmation of Young Planetary-Mass Companions on Wide Orbits

The habitability of planets orbiting M-dwarf stars

The Rotation and Galactic Kinematics of Mid M Dwarfs in the Solar Neighborhood

Contact Info

Product

Resources

About