Browsing by Author "Jones, Hugh"

Now showing items 21-35 of 35

    • MagAO Imaging of Long-period Objects (MILO). II. A Puzzling White Dwarf around the Sun-like Star HD 11112 

      Rodigas, Timothy J.; Bergeron, P.; Simon, Amelie; Arriagada, Pamela; Faherty, Jackie; Anglada-Escude, Guillem; Mamajek, Eric E.; Weinberger, Alycia; Butler, R. Paul; Males, Jared R.; Morzinski, Katie; Close, Laird M.; Hinz, Philip M.; Bailey, Jeremy; Carter, Brad; Jenkins, James S.; Jones, Hugh; O'Toole, Simon; Tinney, C. G.; Wittenmyer, Rob; Debes, John (2016-11-10)
      HD 11112 is an old, Sun-like star that has a long-term radial velocity (RV) trend indicative of a massive companion on a wide orbit. Here we present direct images of the source responsible for the trend using the Magellan ...

    • A Method to Achieve High Dynamic Range in a CMOS Image Sensor Using Interleaved Row Readout 

      Wocial, Thomas; Stefanov, Konstantin; Martin, Bill; Barnes, John; Jones, Hugh (2022-11-15)
      We present a readout scheme for CMOS image sensors that can be used to achieve arbitrarily high dynamic range (HDR) in principle. The linear full well capacity (LFWC) in high signal regions was extended 50 times from 20 ...

    • New Planetary Systems from the Calan-Hertfordshire Extrasolar Planet Search and the Core Accretion Mass Limit 

      Jenkins, J. S.; Jones, Hugh; Tuomi, Mikko; Diaz, M.; Cordero, J. P.; Aguayo, A.; Pantoja, B.; Arriagada, P.; Mahu, R.; Brahm, R.; Rojo, P.; Soto, M. G.; Ivanyuk, O.; Becerra Yoma, N.; Day-Jones, A. C.; Ruiz, M. T.; Pavlenko, Y. V.; Barnes, J. R.; Murgas, F.; Pinfield, David; Jones, M. I.; Lopez-Morales, M.; Shectman, S.; Butler, R. P.; Minniti, D. (2017-04-01)
      We report the discovery of eight new giant planets, and updated orbits for four known planets, orbiting dwarf and subgiant stars using the CORALIE, HARPS, and MIKE instruments as part of the Calan–Hertfordshire Extrasolar ...

    • The observed distribution of spectroscopic binaries from the Anglo-Australian Planet Search 

      Jenkins, J. S.; Díaz, M.; Jones, Hugh; Butler, R. P.; Tinney, Chris G.; O'Toole, S. J.; Carter, B.D.; Wittenmyer, R.; Pinfield, David (2015-10-21)
      We report the detection of sixteen binary systems from the Anglo-Australian Planet Search. Solutions to the radial velocity data indicate that the stars have companions orbiting with a wide range of masses, eccentricities ...

    • Primeval very low-mass stars and brown dwarfs -- II. The most metal-poor substellar object 

      Zhang, Z. H.; Homeier, D.; Pinfield, David; Lodieu, N.; Jones, Hugh; Allard, F.; Pavlenko, Ya V. (2017-06-01)
      SDSS J010448.46+153501.8 has previously been classified as an sdM9.5 subdwarf. However, it's very blue J-K colour (-0.15+/-0.17) suggests a much lower metallicity compared to normal sdM9.5 subdwarfs. Here we re-classify ...

    • Radial-velocity fitting challenge : II. First results of the analysis of the data set 

      Dumusque, X.; Borsa, F.; Damasso, M.; Díaz, R. F.; Gregory, P. C.; Hara, N. C.; Hatzes, A.; Rajpaul, V.; Tuomi, Mikko; Aigrain, S.; Anglada-Escudé, G.; Bonomo, A. S.; Boué, G.; Dauvergne, F.; Frustagli, G.; Giacobbe, P.; Haywood, R. D.; Jones, Hugh; Laskar, J.; Pinamonti, M.; Poretti, E.; Rainer, M.; Ségransan, D.; Sozzetti, A.; Udry, S. (2017-02-14)
      Context. Radial-velocity (RV) signals arising from stellar photospheric phenomena are the main limitation for precise RV measurements. Those signals induce RV variations an order of magnitude larger than the signal created ...

    • A Reanalysis of the UVES M Dwarf Planet Search Program 

      Butler, R. P.; Jones, Hugh; Feng, F.; Escude, G. Anglada; Tuomi, M.; Keiser, Sandy (2019-12-02)
      The UVES (Ultraviolet and Visible Spectrometer) M Dwarf Planet Search program surveyed 40 M dwarfs and 1 M giant from 2000 through 2007 March. Two of the M dwarfs were double-lined spectroscopic binaries. The 38 single-lined ...

    • Recovering planet radial velocity signals in the presence of starspot activity in fully convective stars 

      Barnes, John; Anglada Escude, Guillem; Tuomi, Mikko; Jones, Hugh; Feng, F.; Jeffers, S. V.; Haswell, C. A.; Jenkins, J. S.; Petit, P. (2017-04-01)
      Accounting for stellar activity is a crucial component of the search for ever-smaller planets orbiting stars of all spectral types. We use Doppler imaging methods to demonstrate that starspot-induced radial velocity ...

    • A small actively-controlled high-resolution spectrograph based on off-the-shelf components 

      Jones, Hugh; Martin, Bill; Anglada, Guillem; Errmann, Ronny; London, Queen Mary University; Choochalerm, Piyamas; Boonsri, Chantira (2021-02-01)
      We present the design and testing of a prototype in-plane echelle spectrograph based on an actively controlled fiber-fed double-pass design. This system aims to be small and efficient with the minimum number of optical ...

    • Spectroscopic signatures of youth in low-mass kinematic candidates of young moving groups 

      Galvez-Ortiz, M. C.; Kuznetsov, M.; Clarke, J. R. A.; Pavlenko, Ya. V.; Folkes, S. L.; Pinfield, David; Jones, Hugh; Jenkins, J. S.; Barnes, John; Burmingham, B.; Day-Jones, A. C.; Martin, E. L.; Garcia Perez, A. E.; del Burgo, C.; Pokorny, R. S. (2014-04-21)
      We present a study of age-related spectral signatures observed in 25 young low-mass objects that we have previously determined as possible kinematic members of five young moving groups: the Local Association (Pleiades ...

    • A terrestrial planet candidate in a temperate orbit around Proxima Centauri 

      Anglada-Escude, Guillem; Amado, Pedro J.; Barnes, John; Berdinas, Zaira M.; Butler, Paul; Coleman, Gavin A. L.; de la Cueva, Ignacio; Dreizler, Stefan; Endl, Michael; Giesers, Benjamin; Jeffers, Sandra V.; Jenkins, James S.; Jones, Hugh; Kiraga, Marcin; Kurster, Martin; Lopez-Gonzalez, Maria J.; Marvin, Christopher J.; Morales, Nicolas; Morin, Julien; Nelson, Richard P.; Ortiz, Jose L.; Ofir, Aviv; Paardekooper, Sijme-Jan; Reiners, Ansgar; Rodriguez, Eloy; Rodriguez-Lopez, Cristina; Sarmiento, Luis F.; Strachan, John P.; Tsapras, Yiannis; Tuomi, Mikko; Zechmeister, Mathias (2016-08-25)
      At a distance of 1.295 parsecs, the red dwarf Proxima Centauri (α Centauri C, GL 551, HIP 70890 or simply Proxima) is the Sun’s closest stellar neighbour and one of the best-studied low-mass stars. It has an effective ...

    • Transmission properties of tapered optical fibres: Simulations and experimental measurements 

      Choochalerm, Piyamas; Martin, Bill; Jones, Hugh; Errmann, Ronny; Yerolatsitis, Stephanos; Wright, Thomas; Buisset, Christophe (2021-10-01)
      We measured the transmission of tapered and untapered optical fibres as a function of input beam numerical aperture at 635 nm. The tapered fibres were fabricated with an adiabatic tapering process from graded and step-index ...

    • Two planets around Kapteyn's star: a cold and a temperate super-Earth orbiting the nearest halo red dwarf 

      Anglada-Escude, Guillem; Arriagada, P.; Tuomi, Mikko; Zechmeister, M.; Jenkins, J. S.; Ofir, A.; Dreizler, S.; Gerlach, E.; Marvin, C. J.; Reiners, A.; Jeffers, S. V.; Butler, R.P.; Vogt, S. S.; Amado, P. J.; Gerlach, E.; Rodríguez-López, C.; Berdiñas, Z. M.; Morin, J.; Crane, J. D.; Shectman, S. A.; Thompson, Ian B.; Diaz, M.; Rivera, E.; Sarmiento, L. F.; Jones, Hugh (2014-09-01)
      Exoplanets of a few Earth masses can be now detected around nearby low-mass stars using Doppler spectroscopy. In this Letter, we investigate the radial velocity variations of Kapteyn's star, which is both a sub-dwarf M-star ...

    • Was Proxima captured by alpha Centauri A and B? 

      Feng, F.; Jones, Hugh (2018-01-21)
      The nearest stellar system consists of the stars Proxima, Alpha Centauri A and B and at least one planet Proxima b. The habitability of Proxima b and any other planets are likely to be significantly influenced by the orbital ...

    • WISEP J061135.13-041024.0 AB: A J-band Flux Reversal Binary at the L/T Transition 

      Gelino, Christopher R.; Smart, R. L.; Marocco, Federico; Kirkpatrick, Davy; Cushing, Michael C.; Mace, Gregory; Mendez, Rene A.; Tinney, C. G.; Jones, Hugh (2014-05-28)
      We present Keck II laser guide star adaptive optics observations of the brown dwarf WISEP J061135.13−041024.0 showing it is a binary with a component separation of 0. 4. This system is one of the six known resolved binaries ...