Photospheric activity, rotation, and magnetic interaction in LHS 6343 A

Herrero, E.; Lanza, A. F.; Ribas, I.; Jordi, C.; Morales, J. C.

doi:10.1051/0004-6361/201220518

Cited by 10 publications

(15 citation statements)

References 66 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In analyzing the pipeline-generated light curve, we detected occasional anomalies during transit events, with the recorded flux systematically larger than expected. These anomalies were also detected by Herrero et al (2013), who attribute them to occultations of spots on LHS 6343 A by LHS 6343 C. The anomalies occur only in the long cadence data, and only when the transit is symmetric around one data point in the Kepler time series, so that the central in-transit flux measurement would be expected to be significantly lower than the surrounding data points. By investigating the pixel-level data, we find that each anomaly has been registered as a cosmic ray by the PA pipeline, and "corrected" to an artificially large value.…”

Section: Kepler Photometrymentioning

confidence: 76%

“…Oshagh et al (2012) analyzed the lack of transit timing variations in the system, finding that any additional companions to LHS 6343 A with an orbital period smaller than 100 days must have a mass smaller than that of Jupiter. With 6 quarters of Kepler data, Herrero et al (2013) measured a photometric rotation period of 13.13 ± 0.02 days for LHS 6343 A. The authors also claimed to observe spotcrossing events during the transits of LHS 6343 A, as well as out-of-transit photometric modulation with a period consistent with the orbital period of LHS 6343 C. Herrero et al (2014) updated this work, concluding that the out-of-transit variations are dominated by relativistic Doppler beaming.…”

Section: Introductionmentioning

confidence: 73%

See 1 more Smart Citation

CHARACTERIZING THE COOL KOIs. VII. REFINED PHYSICAL PROPERTIES OF THE TRANSITING BROWN DWARF LHS 6343 C

Montet

Johnson

Muirhead

et al. 2015

ApJ

View full text Add to dashboard Cite

We present an updated analysis of LHS 6343, a triple system in the Kepler field which consists of a brown dwarf transiting one member of a widely separated M+M binary system. By analyzing the full Kepler data set and 34 Keck/ HIgh Resolution Echelle Spectrometer radial velocity observations, we measure both the observed transit depth and Doppler semiamplitude to 0.5% precision. With Robo-AO and Palomar/PHARO adaptive optics imaging as well as TripleSpec spectroscopy, we measure a model-dependent mass for LHS 6343 C of 62.1 ± 1.2 M Jup and a radius of 0.783 ± 0.011 R Jup . We detect the secondary eclipse in the Kepler data at 3.5σ , measuring e cos ω = 0.0228 ± 0.0008. We also derive a method to measure the mass and radius of a star and transiting companion directly, without any direct reliance on stellar models. The mass and radius of both objects depend only on the orbital period, stellar density, reduced semimajor axis, Doppler semiamplitude, eccentricity, and inclination, as well as the knowledge that the primary star falls on the main sequence. With this method, we calculate a mass and radius for LHS 6343 C to a precision of 3% and 2%, respectively.

show abstract

Section: Kepler Photometrymentioning

confidence: 76%

Section: Introductionmentioning

confidence: 73%

CHARACTERIZING THE COOL KOIs. VII. REFINED PHYSICAL PROPERTIES OF THE TRANSITING BROWN DWARF LHS 6343 C

Montet

Johnson

Muirhead

et al. 2015

ApJ

View full text Add to dashboard Cite

show abstract

“…Evidence of photospheric signatures associated with a possible magnetic star-planet interaction are reviewed by, e.g., Lanza (2011) considering also their possible connection with chromospheric and coronal signatures. Recently, Herrero et al (2013) have discussed further observations supporting the phenomenon.…”

Section: Introductionmentioning

confidence: 81%

Star-planet magnetic interaction and evaporation of planetary atmospheres

Lanza

2013

A&A

Self Cite

View full text Add to dashboard Cite

Context. Stars interact with their close-in planets through radiation, gravitation and magnetic fields. Aims. We investigate the energy input to a planetary atmosphere by reconnection between stellar and planetary magnetic fields and compare it to the energy input of the extreme ultraviolet (EUV) radiation field of the star. Methods. We quantify the power released by magnetic reconnection at the boundary of the planetary magnetosphere that is conveyed to the atmosphere by accelerated electrons. We introduce simple models to evaluate the energy spectrum of the accelerated electrons and the energy dissipated in the atmospheric layers in the polar region of the planet upon which they impinge. A simple transonic isothermal wind flow along field lines is considered to estimate the increase in mass loss rate in comparison with a planet irradiated only by the EUV flux of its host star. Results. We find that energetic electrons can reach levels down to column densities of 10 23 −10 25 m −2 , comparable with or deeper than EUV photons, and increase the mass loss rate up to a factor of 30−50 in close-in (<0.10 AU), massive (≥1.5 Jupiter masses) planets. Mass loss rates up to (0.5−1.0) × 10 9 kg s −1 are found for atmospheres heated by electrons accelerated by magnetic reconnection at the boundary of planetary magnetospheres. On the other hand, average mass loss rates up to (0.3−1.0) × 10 10 kg s −1 are found in the case of magnetic loops interconnecting the planet with the star. Conclusions. The star-planet magnetic interaction provides a remarkable source of energy for planetary atmospheres, generally comparable with or exceeding that of stellar EUV radiation for close-in planets. Therefore, it must be included in models of chemical evolution or evaporation of planetary atmospheres as well as in modelling of light curves of transiting planets at UV wavelengths.

show abstract

“…This phenomenon may be present and detectable in some systems (e.g. Pagano et al 2009;Herrero et al 2013) but not others (e.g. Miller et al 2012;Scandariato et al 2013), however, as the planets of interest for this work are distant (outside 0.3AU), such an interaction is likely to be very weak or absent.…”

Section: Sanchis-ojeda and Winn 2011mentioning

confidence: 92%

Extrasolar Binary Planets. Ii. Detectability by Transit Observations

Lewis

Ochiai

Nagasawa

et al. 2015

ApJ

View full text Add to dashboard Cite

We discuss the detectability of gravitationally bounded pairs of gas-giant planets (which we call "binary planets") in extrasolar planetary systems that are formed through orbital instability followed by planet-planet dynamical tides during their close encounters, based on the results of N-body simulations by Ochiai, Nagasawa and Ida (Paper I). Paper I showed that the formation probability of a binary is as much as ∼ 10% for three giant planet systems that undergo orbital instability, and after post-capture long-term tidal evolution, the typical binary separation is 3-5 times the sum of physical radii of the planets. The binary planets are stable during main sequence lifetime of solar-type stars, if the stellarcentric semimajor axis of the binary is larger than 0.3 AU. We show that detecting modulations of transit light curves is the most promising observational method to detect binary planets. Since the likely binary separations are comparable to the stellar diameter, the shape of the transit light curve is different from transit to transit, depending on the phase of the binary's orbit. The transit durations and depth for binary planet transits are generally longer and deeper than those for the single planet case. We point out that binary planets could exist among the known inflated gas giant planets or objects classified as false positive detections at orbital radii 0.3 AU, propose a binary planet explanation for the CoRoT candidate SRc01 E2 1066, and show that binary planets are likely to be present in, and could be detected using Kepler-quality data.

show abstract

Photospheric activity, rotation, and magnetic interaction in LHS 6343 A

Cited by 10 publications

References 66 publications

CHARACTERIZING THE COOL KOIs. VII. REFINED PHYSICAL PROPERTIES OF THE TRANSITING BROWN DWARF LHS 6343 C

CHARACTERIZING THE COOL KOIs. VII. REFINED PHYSICAL PROPERTIES OF THE TRANSITING BROWN DWARF LHS 6343 C

Star-planet magnetic interaction and evaporation of planetary atmospheres

Extrasolar Binary Planets. Ii. Detectability by Transit Observations

Contact Info

Product

Resources

About