M-Dwarf Rapid Rotators and the Detection of Relatively Young Multiple M-Star Systems

Rappaport, S.; Swift, Jonathan J.; Levine, Alan M.; Joss, M.; Sanchis-Ojeda, Roberto; Barclay, Thomas; Still, M.; Handler, G.; Oláh, K.; Muirhead, Philip S.; Huber, Daniel; Vida, K.

doi:10.1088/0004-637x/788/2/114

Cited by 30 publications

(31 citation statements)

References 59 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We examine the two that have periodic modulations in the Kepler data that are detectable by eye ( Figure 5). We have not detected periods in the remaining objects, though we note that for KIC 6117602, we have a candidate detection of 80 days, which is at odds with the 0.67 day period reported by Rappaport et al (2014).…”

Section: Comparison To Keplercontrasting

confidence: 74%

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

Newton

Irwin

Charbonneau

et al. 2016

ApJ

274

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

Section: Comparison To Keplercontrasting

confidence: 74%

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

Newton

Irwin

Charbonneau

et al. 2016

ApJ

274

417

View full text Add to dashboard Cite

show abstract

“…We identified multiple rotation periods by adapting the procedures of Rappaport et al (2014) and RG15. This involved generating periodograms for each EB on a uniform frequency grid, using the Python package gatspy (VanderPlas & Ivezić 2015; VanderPlas 2016).…”

Section: Multiple Rotation Periods From the Periodogrammentioning

confidence: 99%

Tidal Synchronization and Differential Rotation of Kepler Eclipsing Binaries

et al. 2017

View full text Add to dashboard Cite

Few observational constraints exist for the tidal synchronization rate of late-type stars, despite its fundamental role in binary evolution. We visually inspected the light curves of 2278 eclipsing binaries (EBs) from the Kepler Eclipsing Binary Catalog to identify those with starspot modulations, as well as other types of out-of-eclipse variability. We report rotation periods for 816 EBs with starspot modulations, and find that 79% of EBs with orbital periods of less than 10 days are synchronized. However, a population of short-period EBs exists, with rotation periods typically 13% slower than synchronous, which we attribute to the differential rotation of highlatitude starspots. At 10 days, there is a transition from predominantly circular, synchronized EBs to predominantly eccentric, pseudosynchronized EBs. This transition period is in good agreement with the predicted and observed circularization period for Milky Way field binaries. At orbital periods greater than about 30 days, the amount of tidal synchronization decreases. We also report 12 previously unidentified candidate δ Scuti and γ Doradus pulsators, as well as a candidate RS CVn system with an evolved primary that exhibits starspot occultations. For short-period contact binaries, we observe a period-color relation and compare it to previous studies. As a whole, these results represent the largest homogeneous study of tidal synchronization of late-type stars.

show abstract

“…We estimate the probability of a nearby interloper star with the requisite magnitude of K p 17 randomly lying within 0.4 of KIC 3542116 as 0.1% (see, e.g., Fig. 9 of Rappaport et al 2014b).…”

Section: High-resolution Imagingmentioning

confidence: 99%

Likely transiting exocomets detected by Kepler

Rappaport

Vanderburg

Jacobs

et al. 2017

Monthly Notices of the Royal Astronomical Society

Self Cite

107

View full text Add to dashboard Cite

We present the first good evidence for exocomet transits of a host star in continuum light in data from the Kepler mission. The Kepler star in question, KIC 3542116, is of spectral type F2V and is quite bright at K p = 10. The transits have a distinct asymmetric shape with a steeper ingress and slower egress that can be ascribed to objects with a trailing dust tail passing over the stellar disk. There are three deeper transits with depths of 0.1% that last for about a day, and three that are several times more shallow and of shorter duration. The transits were found via an exhaustive visual search of the entire Kepler photometric data set, which we describe in some detail. We review the methods we use to validate the Kepler data showing the comet transits, and rule out instrumental artefacts as sources of the signals. We fit the transits with a simple dust-tail model, and find that a transverse comet speed of ∼35-50 km s −1 and a minimum amount of dust present in the tail of ∼ 10 16 g are required to explain the larger transits. For a dust replenishment time of ∼10 days, and a comet lifetime of only ∼300 days, this implies a total cometary mass of 3 × 10 17 g, or about the mass of Halley's comet. We also discuss the number of comets and orbital geometry that would be necessary to explain the six transits detected over the four years of Kepler prime-field observations. Finally, we also report the discovery of a single comet-shaped transit in KIC 11084727 with very similar transit and host-star properties.

show abstract

M-Dwarf Rapid Rotators and the Detection of Relatively Young Multiple M-Star Systems

Cited by 30 publications

References 59 publications

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

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

Tidal Synchronization and Differential Rotation of Kepler Eclipsing Binaries

Likely transiting exocomets detected by Kepler

Contact Info

Product

Resources

About