Abstract
We report the discovery of 16 detached M dwarf eclipsing binaries with J < 16mag and provide a detailed characterization of three of them, using high-precision infrared light curves from the WFCAM Transit Survey (WTS). Such systems provide the most accurate and model-independent method for measuring the fundamental parameters of these poorly understood yet numerous stars, which currently lack sufficient observations to precisely calibrate stellar evolution models. We fully solve for the masses and radii of three of the systems, finding orbital periods in the range 1.5 < P < 4.9d, with masses spanning 0.35-0.50M ⊙ and radii between 0.38 and 0.50R ⊙, with uncertainties of ∼3.5-6.4 per cent in mass and ∼2.7-5.5 per cent in radius. Close companions in short-period binaries are expected to be tidally locked into fast rotational velocities, resulting in high levels of magnetic activity. This is predicted to inflate their radii by inhibiting convective flow and increasing starspot coverage. The radii of the WTS systems are inflated above model predictions by ∼3-12 per cent, in agreement with the observed trend, despite an expected lower systematic contribution from starspot signals at infrared wavelengths. We searched for correlation between the orbital period and radius inflation by combining our results with all existing M dwarf radius measurements of comparable precision, but we found no statistically significant evidence for a decrease in radius inflation for longer period, less active systems. Radius inflation continues to exists in non-synchronized systems, indicating that the problem remains even for very low activity M dwarfs. Resolving this issue is vital not only for understanding the most populous stars in the Universe, but also for characterizing their planetary companions, which hold the best prospects for finding Earth-like planets in the traditional habitable zone.
| Original language | English |
|---|---|
| Pages (from-to) | 1507-1532 |
| Number of pages | 26 |
| Journal | Monthly Notices of the Royal Astronomical Society |
| Volume | 426 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - 21 Oct 2012 |
| Externally published | Yes |
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Keywords
- Binaries: eclipsing
- Stars: fundamental parameters
- Stars: late-type
- Stars: magnetic field
- Stars: rotation
- Surveys
ASJC Scopus subject areas
- Space and Planetary Science
- Astronomy and Astrophysics
Cite this
Discovery and characterization of detached M dwarf eclipsing binaries in the WFCAM Transit Survey. / Birkby, Jayne; Nefs, Bas; Hodgkin, Simon; Kovács, Gábor; Sipocz, Brigitta; Pinfield, David; Snellen, Ignas; Mislis, Dimitrios; Murgas, Felipe; Lodieu, Nicolas; de Mooij, Ernst; Goulding, Niall; Cruz, Patricia; Stoev, Hristo; Cappetta, Michele; Palle, Enric; Barrado, David; Saglia, Roberto; Martin, Eduardo; Pavlenko, Yakiv.
In: Monthly Notices of the Royal Astronomical Society, Vol. 426, No. 2, 21.10.2012, p. 1507-1532.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Discovery and characterization of detached M dwarf eclipsing binaries in the WFCAM Transit Survey
AU - Birkby, Jayne
AU - Nefs, Bas
AU - Hodgkin, Simon
AU - Kovács, Gábor
AU - Sipocz, Brigitta
AU - Pinfield, David
AU - Snellen, Ignas
AU - Mislis, Dimitrios
AU - Murgas, Felipe
AU - Lodieu, Nicolas
AU - de Mooij, Ernst
AU - Goulding, Niall
AU - Cruz, Patricia
AU - Stoev, Hristo
AU - Cappetta, Michele
AU - Palle, Enric
AU - Barrado, David
AU - Saglia, Roberto
AU - Martin, Eduardo
AU - Pavlenko, Yakiv
PY - 2012/10/21
Y1 - 2012/10/21
N2 - We report the discovery of 16 detached M dwarf eclipsing binaries with J < 16mag and provide a detailed characterization of three of them, using high-precision infrared light curves from the WFCAM Transit Survey (WTS). Such systems provide the most accurate and model-independent method for measuring the fundamental parameters of these poorly understood yet numerous stars, which currently lack sufficient observations to precisely calibrate stellar evolution models. We fully solve for the masses and radii of three of the systems, finding orbital periods in the range 1.5 < P < 4.9d, with masses spanning 0.35-0.50M ⊙ and radii between 0.38 and 0.50R ⊙, with uncertainties of ∼3.5-6.4 per cent in mass and ∼2.7-5.5 per cent in radius. Close companions in short-period binaries are expected to be tidally locked into fast rotational velocities, resulting in high levels of magnetic activity. This is predicted to inflate their radii by inhibiting convective flow and increasing starspot coverage. The radii of the WTS systems are inflated above model predictions by ∼3-12 per cent, in agreement with the observed trend, despite an expected lower systematic contribution from starspot signals at infrared wavelengths. We searched for correlation between the orbital period and radius inflation by combining our results with all existing M dwarf radius measurements of comparable precision, but we found no statistically significant evidence for a decrease in radius inflation for longer period, less active systems. Radius inflation continues to exists in non-synchronized systems, indicating that the problem remains even for very low activity M dwarfs. Resolving this issue is vital not only for understanding the most populous stars in the Universe, but also for characterizing their planetary companions, which hold the best prospects for finding Earth-like planets in the traditional habitable zone.
AB - We report the discovery of 16 detached M dwarf eclipsing binaries with J < 16mag and provide a detailed characterization of three of them, using high-precision infrared light curves from the WFCAM Transit Survey (WTS). Such systems provide the most accurate and model-independent method for measuring the fundamental parameters of these poorly understood yet numerous stars, which currently lack sufficient observations to precisely calibrate stellar evolution models. We fully solve for the masses and radii of three of the systems, finding orbital periods in the range 1.5 < P < 4.9d, with masses spanning 0.35-0.50M ⊙ and radii between 0.38 and 0.50R ⊙, with uncertainties of ∼3.5-6.4 per cent in mass and ∼2.7-5.5 per cent in radius. Close companions in short-period binaries are expected to be tidally locked into fast rotational velocities, resulting in high levels of magnetic activity. This is predicted to inflate their radii by inhibiting convective flow and increasing starspot coverage. The radii of the WTS systems are inflated above model predictions by ∼3-12 per cent, in agreement with the observed trend, despite an expected lower systematic contribution from starspot signals at infrared wavelengths. We searched for correlation between the orbital period and radius inflation by combining our results with all existing M dwarf radius measurements of comparable precision, but we found no statistically significant evidence for a decrease in radius inflation for longer period, less active systems. Radius inflation continues to exists in non-synchronized systems, indicating that the problem remains even for very low activity M dwarfs. Resolving this issue is vital not only for understanding the most populous stars in the Universe, but also for characterizing their planetary companions, which hold the best prospects for finding Earth-like planets in the traditional habitable zone.
KW - Binaries: eclipsing
KW - Stars: fundamental parameters
KW - Stars: late-type
KW - Stars: magnetic field
KW - Stars: rotation
KW - Surveys
UR - http://www.scopus.com/inward/record.url?scp=84867050333&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84867050333&partnerID=8YFLogxK
U2 - 10.1111/j.1365-2966.2012.21514.x
DO - 10.1111/j.1365-2966.2012.21514.x
M3 - Article
AN - SCOPUS:84867050333
VL - 426
SP - 1507
EP - 1532
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
SN - 0035-8711
IS - 2
ER -