Now showing items 524-543 of 574

  • Transiting the Sun : the impact of stellar activity on X-ray and ultraviolet transits 

    Llama, Joe; Shkolnik, E. L. (2015-03-19) - Journal article
    Transits of hot Jupiters in X-rays and the ultraviolet have been shown to be both deeper and more variable than the corresponding optical transits. This variability has been attributed to hot Jupiters having extended ...
  • Transiting the Sun. II. The impact of stellar activity on Lyα transits 

    Llama, J.; Shkolnik, E. L. (2016-01-22) - Journal article
    High-energy observations of the Sun provide an opportunity to test the limits of our ability to accurately measure the properties of transiting exoplanets in the presence of stellar activity. Here we insert the transit of ...
  • Transits and starspots in the WASP-6 planetary system 

    Tregloan-Reed, Jeremy; Southworth, John; Burgdorf, M.; Novati, S. Calchi; Dominik, Martin; Finet, F.; Jørgensen, U. G.; Maier, G.; Mancini, L.; Prof, S.; Ricci, D.; Snodgrass, C.; Bozza, V.; Browne, Paul; Dodds, Peter; Gerner, T.; Harpsøe, K.; Hinse, T. C.; Hundertmark, Markus Peter Gerhard; Kains, Noé; Kerins, E.; Liebig, Christine Elisabeth; Penny, M. T.; Rahvar, S.; Sahu, K.; Scarpetta, G.; Schäfer, S.; Schönebeck, F.; Skottfelt, J.; Surdej, J. (2015-06-21) - Journal article
    We present updates to prism, a photometric transit-starspot model, and GEMC, a hybrid optimization code combining MCMC and a genetic algorithm. We then present high-precision photometry of four transits in the WASP-6 ...
  • The transterminator ion flow at Venus at solar minimum 

    Wood, A. G.; Pryse, S. E.; Grande, M.; Whittaker, I. C.; Coates, A. J.; Husband, K.; Baumjohann, W.; Zhang, T. L.; Mazelle, C.; Kallio, E.; Fraenz, M.; McKenna-Lawlor, S.; Wurz, P. (2012-12) - Journal article
    The transterminator ion flow in the Venusian ionosphere is observed at solar minimum for the first time. Such a flow, which transports ions from the day to the nightside, has been observed previously around solar maximum. ...
  • Triple trouble for XZ Tau : deep imaging with the Jansky Very Large Array 

    Forgan, D.; Ivison, R. J.; Sibthorpe, B.; Greaves, J. S.; Ibar, E. (2014-04-21) - Journal article
    We present new observations of the XZ Tau system made at high angular resolution (55 mas) with the Karl G. Jansky Very Large Array (VLA) at a wavelength of 7 mm. Observations of XZ Tau made with the VLA in 2004 appeared ...
  • Turbulence in the interstellar medium 

    Falceta-Goncalves, D.; Kowal, G.; Falgarone, E.; Chian, A. C. -L. (2014-05-16) - Journal article
    Turbulence is ubiquitous in the insterstellar medium and plays a major role in several processes such as the formation of dense structures and stars, the stability of molecular clouds, the amplification of magnetic fields, ...
  • Two mechanisms for dust gap opening in protoplanetary discs 

    Dipierro, Giovanni; Laibe, Guillaume; Price, Daniel J.; Lodato, Giuseppe (2016-03-01) - Journal article
    We identify two distinct physical mechanisms for dust gap opening by embedded planets in protoplanetary discs based on the symmetry of the drag-induced motion around the planet: (I) a mechanism where low-mass planets, that ...
  • Type Ia supernova progenitors and chemical enrichment in hydrodynamical simulations. I. The single-degenerate scenario 

    Martinez, Noelia Jimenez; Tissera, P.B.; Matteucci, F. (2015-09-10) - Journal article
    The nature of the Type Ia supernova (SN Ia) progenitors remains uncertain. This is a major issue for galaxy evolution models since both chemical and energetic feedback plays a major role in the gas dynamics, star formation, ...
  • Ultraviolet and extreme-ultraviolet emissions at the flare footpoints observed by atmosphere imaging assembly 

    Qiu, J.; Sturrock, Z.; Longcope, D.W.; Klimchuk, J.A.; Liu, W.-J. (2013-09-01) - Journal article
    A solar flare is composed of impulsive energy release events by magnetic reconnection, which forms and heats flare loops. Recent studies have revealed a two-phase evolution pattern of UV 1600 Å emission at the feet of these ...
  • Uncertainties in water chemistry in disks : an application to TW Hydrae 

    Kamp, I.; Thi, W. -F.; Meeus, G.; Woitke, P.; Pinte, C.; Meijerink, R.; Spaans, M.; Pascucci, I.; Aresu, G.; Dent, W. R. F. (2013-11) - Journal article
    Context. This paper discusses the sensitivity of water lines to chemical processes and radiative transfer for the protoplanetary disk around TW Hya. The study focuses on the Herschel spectral range in the context of new ...
  • Uncovering the birth of a coronal mass ejection from two-viewpoint SECCHI observations 

    Vourlidas, A.; Syntelis, P.; Tsinganos, K. (2012-10) - Journal article
    We investigate the initiation and formation of Coronal Mass Ejections (CMEs) via a detailed two-viewpoint analysis of low corona observations of a relatively fast CME acquired by the SECCHI instruments aboard the STEREO ...
  • Understanding the Mg II and Hα spectra in a highly dynamical solar prominence 

    Heinzel, P.; Schmieder, B.; Mein, N.; Gunar, S. (2015-02-10) - Journal article
    Mg ii h and k and Hα spectra in a dynamical prominence have been obtained along the slit of the Interface Region Imaging Spectrograph (IRIS) and with the Meudon Multi-channel Subtractive Double Pass spectrograph on 2013 ...
  • Using biogenic sulfur gases as remotely detectable biosignatures on anoxic planets 

    Domagal-Goldman, S.; Meadows, V. S.; Claire, M.W.; Kasting, J. F. (2011-06-27) - Journal article
    We used one-dimensional photochemical and radiative transfer models to study the potential of organic sulfur compounds (CS2, OCS, CH3SH, CH3SCH3, and CH3S2CH3) to act as remotely detectable biosignatures in anoxic exoplanetary ...
  • Using dimers to measure biosignatures and atmospheric pressure for terrestrial exoplanets 

    Misra, A.; Meadows, V.; Claire, M.; Crisp, D. (2014-02-19) - Journal article
    We present a new method to probe atmospheric pressure on Earth-like planets using (O-O) dimers in the near-infrared. We also show that dimer features could be the most readily detectable biosignatures for Earth-like ...
  • The UV continua and inferred stellar populations of galaxies at z ≃ 7-9 revealed by the Hubble Ultra-Deep Field 2012 campaign 

    Dunlop, J. S.; Rogers, A. B.; McLure, R. J.; Ellis, R. S.; Robertson, B. E.; Koekemoer, A.; Dayal, P.; Curtis-Lake, E.; Wild, Vivienne; Charlot, S.; Bowler, R. A. A.; Schenker, M. A.; Ouchi, M.; Ono, Y.; Cirasuolo, M.; Furlanetto, S. R.; Stark, D. P.; Targett, T. A.; Schneider, E. (2013-07-11) - Journal article
    We use the new ultra-deep, near-infrared imaging of the Hubble Ultra-Deep Field (HUDF) provided by our UDF12 Hubble Space Telescope (HST) Wide Field Camera 3/IR campaign to explore the rest-frame ultraviolet (UV) properties ...
  • V5852 Sgr : an unusual nova possibly associated with the Sagittarius stream 

    Aydi, E.; Mróz, P.; Whitelock, P. A.; Mohamed, S.; Wyrzykowski, Ł.; Udalski, A.; Vaisanen, P.; Nagayama, T.; Dominik, M.; Scholz, A.; Onozato, H.; Williams, R. E.; Hodgkin, S. T.; Nishiyama, S.; Yamagishi, M.; Smith, A. M. S.; Ryu, T.; Iwamatsu, A.; Kawamata, I. (2016-09-11) - Journal article
    We report spectroscopic and photometric follow-up of the peculiar nova V5852~Sgr (discovered as OGLE-2015-NOVA-01), which exhibits a combination of features from different nova classes. The photometry shows a flat-topped ...
  • Validation of the magnetic energy vs. helicity scaling in solar magnetic structures 

    Tziotziou, K.; Moraitis, K.; Georgoulis, M.K.; Archontis, V. (2014-10) - Journal item
    Aims. We assess the validity of the free magnetic energy – relative magnetic helicity diagram for solar magnetic structures. Methods. We used two different methods of calculating the free magnetic energy and the relative ...
  • Variability in the CO ro-vibrational lines from HD163296 

    Bertelsen, Rosina P. Hein; Kamp, I.; Plas, G. van der; van den Ancker, M. E.; Waters, L. B. F. M.; Thi, W. -F.; Woitke, Peter (2016-05-11) - Journal article
    We present for the first time a direct comparison of multi-epoch (2001–2002 and 2012) CO ro-vibrational emission lines from HD 163296. We find that both the line shapes and the FWHM (full width at half-maximum) differ ...
  • Variability in young very low mass stars : two surprises from spectrophotometric monitoring 

    Bozhinova, Inna Nikolaeva; Scholz, Alexander; Eislöffel, J. (2016-05-21) - Journal article
    We present simultaneous photometric and spectroscopic observations of seven young and highly variable M dwarfs in star-forming regions in Orion, conducted in four observing nights with FOcal Reducer and low dispersion ...
  • Variable stars in the globular cluster NGC 7492 : new discoveries and physical parameter determination 

    Figuera Jaimes, R.; Arellano Ferro, A.; Bramich, D.M.; Giridhar, S.; Kuppuswamy, K. (2013-08) - Journal article
    Aims. We have performed a photometric V,R,I CCD time-series analysis with a baseline of about eight years of the outer-halo globular cluster NGC 7492 with the aim of searching for new variables and using these (and the ...