Now showing items 1-20 of 25

  • The 2014-2017 outburst of the young star ASASSN-13db. A time-resolved picture of a very-low-mass star between EXors and FUors 

    Sicilia-Aguilar, A.; Oprandi, A.; Froebrich, D.; Fang, M.; Prieto, J. L.; Stanek, K.; Scholz, A.; Kochanek, C. S.; Henning, Th.; Gredel, R.; Holoien, T. W.-S.; Rabus, M.; Shappee, B. J.; Billington, S. J.; Campbell-White, J.; Zegmott, T. J. (2017-11) - Journal article
    Context. ASASSN-13db is a M5-type star with a protoplanetary disk, the lowest mass star known to experience accretion outbursts. Since its discovery in 2013, it has experienced two outbursts, the second of which started ...
  • Atmospheres of brown dwarfs 

    Helling, Christiane; Casewell, Sarah (2014) - Journal item
    Brown Dwarfs are the coolest class of stellar objects known to date. Our present perception is that Brown Dwarfs follow the principles of star formation, and that Brown Dwarfs share many characteristics with planets. Being ...
  • Characterization of low-mass, wide-separation substellar companions to stars in upper Scorpius : near-infrared photometry and spectroscopy 

    Lachapelle, F.-R.; Lafrenière, D.; Gagné, J.; Jayawardhana, R.; Janson, M.; Helling, C.; Witte, S. (2015-03-20) - Journal article
    We present new 0.9–2.45 μm spectroscopy (R ∼ 1000), and Y, J, H, Ks,L photometry, obtained at Gemini North, of three low-mass brown dwarf companions on wide orbits around young stars of the Upper Scorpius OB association: ...
  • Could a change in magnetic field geometry cause the break in the wind-activity relation? 

    Vidotto, Aline; Donati, J.-F.; Jardine, Moira Mary; See, Wyke Chun Victor; Petit, P.; Boisse, I.; Boro Saikia, S.; Hébrard, E.; Jeffers, Sandra Victoria; Marsden, S. C.; Morin, J. (2016-01-01) - Journal article
    Wood et al. suggested that mass-loss rate is a function of X-ray flux (dot{M}∝ F_x^{1.34}) for dwarf stars with Fx ≲ Fx,6 ≡ 106 erg cm-2 s-1. However, more active stars do not obey this relation. These authors suggested ...
  • A deep staring campaign in the σ Orionis cluster. Variability in substellar members 

    Elliott, P.; Scholz, A.; Jayawardhana, R.; Eisloffel, J.; Hebrard, E. M. (2017-12-07) - Journal article
    Context. The young star cluster near σ Orionis is one of the primary environments to study the properties of young brown dwarfs down to masses comparable to those of giant planets. Aims. Deep optical imaging is used to ...
  • The disk around the brown dwarf KPNO TAU 3 

    Broekhoven-Fiene, H.; Matthews, B.; Duchêne, G.; Di Francesco, J.; Scholz, A.; Chrysostomou, A.; Jayawardhana, R. (2014-07-10) - Journal article
    We present submillimeter observations of the young brown dwarfs KPNO Tau 1, KPNO Tau 3, and KPNO Tau 6 at 450 μm and 850 μm taken with the Submillimetre Common-User Bolometer Array on the James Clerk Maxwell Telescope. ...
  • The EBLM project : II. A very hot, low-mass M dwarf in an eccentric and long-period, eclipsing binary system from the SuperWASP survey 

    Gómez Maqueo Chew, Y.; Morales, J.C.; Faedi, F.; García-Melendo, E.; Hebb, L.; Rodler, F.; Deshpande, R.; Mahadevan, S.; McCormac, J.; Barnes, R.; Triaud, A.H.M.J.; Lopez-Morales, M.; Skillen, I.; Collier Cameron, A.; Joner, M.D.; Laney, C.D.; Stephens, D.C.; Stassun, K.G.; Cargile, P.A.; Montañés-Rodríguez, P. (2014-12) - Journal article
    In this paper, we derive the fundamental properties of 1SWASPJ011351.29+314909.7 (J0113+31), a metal-poor (−0.40 ± 0.04 dex), eclipsing binary in an eccentric orbit (~0.3) with an orbital period of ~14.277 d. Eclipsing M ...
  • The EBLM project : III. A Saturn-size low-mass star at the hydrogen-burning limit 

    Von Boetticher, Alexander; Triaud, Amaury H.M.J.; Queloz, DIdier; Gill, Sam; Lendl, Monika; Delrez, Laetitia; Anderson, David R.; Cameron, Andrew Collier; Faedi, Francesca; Gillon, Michaël; Chew, Yilen Gómez Maqueo; Hebb, Leslie; Hellier, Coel; Jehin, Emmanuël; Maxted, Pierre F.L.; Martin, David V.; Pepe, Francesco; Pollacco, Don; Ségransan, Damien; Smalley, Barry; Udry, Stéphane; West, Richard (2017-08-01) - Journal article
    We report the discovery of an eclipsing binary system with mass-ratio q ∼ 0.07. After identifying a periodic photometric signal received by WASP, we obtained CORALIE spectroscopic radial velocities and follow-up light ...
  • The EBLM project I. Physical and orbital parameters, including spin-orbit angles, of two low-mass eclipsing binaries on opposite sides of the brown dwarf limit 

    Triaud, A. H. M. J.; Hebb, L.; Anderson, D. R.; Cargile, P.; Collier Cameron, A.; Doyle, A. P.; Faedi, F.; Gillon, M.; Gomez Maqueo Chew, Y.; Hellier, C.; Jehin, E.; Maxted, P.; Naef, D.; Pepe, F.; Pollacco, D.; Queloz, D.; Ségransan, D.; Smalley, B.; Stassun, K.; Udry, S.; West, R. G. (2013-01) - Journal article
    This paper introduces a series of papers aiming to study the dozens of low-mass eclipsing binaries (EBLM), with F, G, K primaries, that have been discovered in the course of the WASP survey. Our objects are mostly single-line ...
  • Effect of UV radiation on the spectral fingerprints of Earth-like planets orbiting M stars 

    Rugheimer, S.; Kaltenegger, L.; Segura, A.; Linsky, J.; Mohanty, S. (2015-08-10) - Journal article
    We model the atmospheres and spectra of Earth-like planets orbiting the entire grid of M dwarfs for active and inactive stellar models with Teff = 2300 K to Teff = 3800 K and for six observed MUSCLES M dwarfs with UV ...
  • Effects of M dwarf magnetic fields on potentially habitable planets 

    Vidotto, A.A.; Jardine, M.; Morin, J.; Donati, J.-F.; Lang, P.; Russell, A.J.B. (2013-09-02) - Journal article
    We investigate the effect of the magnetic fields of M dwarf (dM) stars on potentially habitable Earth-like planets. These fields can reduce the size of planetary magnetospheres to such an extent that a significant fraction ...
  • The effects of stellar winds on the magnetospheres and potential habitability of exoplanets 

    See, Wyke Chun Victor; Jardine, M.; Vidotto, A.A.; Marsden, S.C.; Jeffers, S.V.; Do Nascimento, J.D. (2014-10) - Journal article
    Context. The principle definition of habitability for exoplanets is whether they can sustain liquid water on their surfaces, i.e. that they orbit within the habitable zone. However, the planet’s magnetosphere should also ...
  • Exploring the magnetic topologies of cool stars 

    Morin, J.; Donati, J.-F.; Petit, P.; Albert, L.; Auriére, M.; Cabanac, R.; Catala, C.; Delfosse, X.; Dintrans, B.; Fares, R.; Forveille, T.; Gastine, T.; Jardine, M.; Konstantinova-Antova, R.; Lanoux, J.; Lignires, F.; Morgenthaler, A.; Paletou, F.; Velez, J. C. Ramirez; Solanki, S. K.; Thado, S.; Van Grootel, V. (Cambridge University Press, 2011-08) - Conference item
    Magnetic fields of cool stars can be directly investigated through the study of the Zeeman effect on photospheric spectral lines using several approaches. With spectroscopic measurement in unpolarised light, the total ...
  • Extended baseline photometry of rapidly changing weather patterns on the brown dwarf binary Luhman-16 

    Street, R. A.; Fulton, B. J.; Scholz, A.; Horne, Keith; Helling, C.; Juncher, D.; Lee, G.; Valenti, S. (2015-10-20) - Journal article
    Luhman-16 (WISE J1049-5319) was recently discovered to be a nearby (∼2 pc) brown dwarf binary that exhibits a high degree of photometric variability (Δm ∼ 0.1 mag). This is thought to be due to the evolution of "cloud" ...
  • Long-term variability of T Tauri stars using WASP 

    Rigon, Laura; Scholz, Alexander; Anderson, David; West, Richard (2017-03-01) - Journal article
    We present a reference study of the long-term optical variability of young stars using data from the WASP project. Our primary sample is a group of well-studied classical T Tauri stars (CTTSs), mostly in Taurus-Auriga. ...
  • Multiple views of magnetism in cool stars 

    Morin, J.; Jardine, Moira Mary; Reiners, A.; Shulyak, D.; Beeck, B.; Hallinan, G.; Hebb, Leslie; Hussain, Gaitee Ara Jaffer; Jeffers, Sandra Victoria; Kochukhov, O.; Vidotto, Aline; Walkowicz, L. (2013-02-01) - Journal article
    Magnetic fields are regarded as a crucial element for our understanding of stellar physics. They can be studied with a variety of methods which provide complementary – and sometimes contradictory – information about the ...
  • The MUSCLES Treasury Survey. I. Motivation and overview 

    France, Kevin; Parke Loyd, R. O.; Youngblood, Allison; Brown, Alexander; Schneider, P. Christian; Hawley, Suzanne L.; Froning, Cynthia S.; Linsky, Jeffrey L.; Roberge, Aki; Buccino, Andrea P.; Davenport, James R. A.; Fontenla, Juan M.; Kaltenegger, Lisa; Kowalski, Adam F.; Mauas, Pablo J. D.; Miguel, Yamila; Redfield, Seth; Rugheimer, Sarah; Tian, Feng; Vieytes, Mariela C.; Walkowicz, Lucianne M.; Weisenburger, Kolby L. (2016-03-22) - Journal article
    Ground- and space-based planet searches employing radial velocity techniques and transit photometry have detected thousands of planet-hosting stars in the Milky Way. With so many planets discovered, the next step toward ...
  • The MUSCLES Treasury Survey. II. Intrinsic Lyα and extreme ultraviolet spectra of K and M dwarfs with exoplanets 

    Youngblood, Allison; France, Kevin; Loyd, R. O. Parke; Linsky, Jeffrey L.; Redfield, Seth; Schneider, P. Christian; Wood, Brian E.; Brown, Alexander; Froning, Cynthia; Miguel, Yamila; Rugheimer, Sarah; Walkowicz, Lucianne (2016-06-20) - Journal article
    The ultraviolet (UV) spectral energy distributions (SEDs) of low-mass (K- and M-type) stars play a critical role in the heating and chemistry of exoplanet atmospheres, but are not observationally well-constrained. Direct ...
  • The MUSCLES Treasury Survey. III. X-ray to infrared spectra of 11 M and K stars hosting planets 

    Loyd, R. O. P.; France, Kevin; Youngblood, Allison; Schneider, Christian; Brown, Alexander; Hu, Renyu; Linsky, Jeffrey; Froning, Cynthia S.; Redfield, Seth; Rugheimer, Sarah; Tian, Feng (2016-06-20) - Journal article
    We present a catalog of panchromatic spectral energy distributions (SEDs) for 7 M and 4 K dwarf stars that span X-ray to infrared wavelengths (5 Å -5.5 μm). These SEDs are composites of Chandra or XMM-Newton data from 5-∼50 ...
  • The MUSCLES Treasury Survey. IV. : Scaling relations for ultraviolet, Ca II K, and energetic particle fluxes from M dwarfs 

    Youngblood, Allison; France, Kevin; Loyd, R. O. Parke; Brown, Alexander; Mason, James P.; Schneider, P. Christian; Tilley, Matt A.; Berta-Thompson, Zachory K.; Buccino, Andrea; Froning, Cynthia S.; Hawley, Suzanne L.; Linsky, Jeffrey; Mauas, Pablo J. D.; Redfield, Seth; Kowalski, Adam; Miguel, Yamila; Newton, Elisabeth R.; Rugheimer, Sarah; Segura, Antigona; Roberge, Aki; Vieytes, Mariela (2017-06-28) - Journal article
    Characterizing the UV spectral energy distribution (SED) of an exoplanet host star is critically important for assessing its planet's potential habitability, particularly for M dwarfs, as they are prime targets for current ...