Monte Carlo approach to turbulence (2009)
Düben, P., Homeier, D., Jansen, K., Mesterhazy, D., Münster, G.
The behavior of the one-dimensional random-force-driven Burgers equation is investigated in the path integral formalism on a discrete space-time lattice. We show that by means of Monte Carlo methods...
Koester, D., Voss, B., Napiwotzki, R., Christlieb, N., Homeier, D., Lisker, T., ...
The ESO Supernova Ia Progenitor Survey (SPY) took high-resolution spectra of more than 1000 white dwarfs and pre-white dwarfs. About two thirds of the stars observed are hydrogen-dominated DA white...
Spectral synthesis of circumstellar disks - application to white dwarf debris disks (2009)
Huegelmeyer, S. D., Dreizler, S., Homeier, D., Hauschildt, P.
Gas and dust disks are common objects in the universe and can be found around various objects, e.g. young stars, cataclysmic variables, active galactic nuclei, or white dwarfs. The light that we...
Radiative transfer in circumstellar disks - I. 1D models for GQ Lupi (2009)
Huegelmeyer, S. D., Dreizler, S., Hauschildt, P. H., Seifahrt, A., Homeier, D., Barman, T.
We present a new code for the calculation of the 1D structure and synthetic spectra of accretion disks. The code is an extension of the general purpose stellar atmosphere code PHOENIX and is...
Dreizler, S., Reiners, A., Homeier, D., Noll, M.
The detection of extrasolar planets' atmospheres requires very demanding observations. For planets that can not be spatially separated from their host stars, i.e. the vast majority of planets, the...
The discovery of an M4+T8.5 binary system (2009)
Burningham, Ben, Pinfield, D. J., Leggett, S. K., Tinney, C. G., Liu, M. C., Homeier, D., ...
We report the discovery of a T8.5 dwarf, which is a companion to the M4 dwarf Wolf 940. At a distance of 12.50 (+0.75,-0.67) pc, the angular separation of 32arcsec corresponds to a projected...
Koester, D., Voss, B., Napiwotzki, R., Christlieb, N., Homeier, D., Lisker, T., ...
Original article can be found at: http://www.aanda.org/ Copyright The European Southern Observatory (ESO) DOI: 10.1051/0004-6361/200912531
Monte Carlo simulations of the randomly forced Burgers equation (2008)
Düben, P., Homeier, D., Jansen, K., Mesterhazy, D., Münster, G., Urbach, C.
The behaviour of the one--dimensional random--forced Burgers equation is investigated in the path integral formalism, using a discrete space--time lattice. We show that by means of Monte Carlo...
A comparison of chemistry and dust cloud formation in ultracool dwarf model atmospheres (2008)
Helling, Ch., Ackerman, A., Allard, F., Dehn, M., Hauschildt, P., Homeier, D., ...
The atmospheres of substellar objects contain clouds of oxides, iron, silicates, and other refractory condensates. Water clouds are expected in the coolest objects. The opacity of these `dust' clouds...
Homeier, D., Jansen, K., Mesterhazy, D., Urbach, C.
We investigate the behaviour of stochastic differential equations, especially Burgers' eq., by means of Monte-Carlo-techniques.
A Hubble Space Telescope transit light curve for GJ436b (2008)
Bean, J. L., Benedict, G. F., Charbonneau, D., Homeier, D., Taylor, D. C., McArthur, B., ...
We present time series photometry for six partial transits of GJ436b obtained with the Fine Guidance Sensor instrument on the Hubble Space Telescope (HST). Our analysis of these data yields...
Exploring the substellar temperature regime down to ~550K (2008)
Burningham, Ben, Pinfield, D. J., Leggett, S. K., Tamura, M., Lucas, P. W., Homeier, D., ...
We report the discovery of three very late T dwarfs in the UKIRT Infrared Deep Sky Survey (UKIDSS) Third Data Release: ULAS J101721.40+011817.9 (ULAS1017), ULAS J123828.51+095351.3 (ULAS1238) and...
Fifteen new T dwarfs discovered in the UKIDSS Large Area Survey (2008)
Pinfield, D. J., Burningham, B., Tamura, M., Leggett, S. K., Lodieu, N., Lucas, P. W., ...
We present the discovery of fifteen new T2.5-T7.5 dwarfs (with estimated distances between ~24-93pc, identified in the first three main data releases of the UKIRT Infrared Deep Sky Survey. This...
Monte Carlo Simulations of the Randomly Forced Burgers Equation (2008)
P. Düben, D. Homeier, G. Münster, K. Jansen, D. Mesterhazy, ...
Internal report | Preprint
A new period determination for the close PG1159 binary SDSSJ212531.92-010745.9 (2007)
Schuh, S., Traulsen, I., Nagel, T., Reiff, E., Homeier, D., Schwager, H., ...
Methods to measure masses of PG1159 stars in order to test evolutionary scenarios are currently based on spectroscopic masses or asteroseismological mass determinations. One recently discovered...
Comparison of cloud models for Brown Dwarfs (2007)
Helling, Ch., Ackerman, A., Allard, F., Dehn, M., Hauschildt, P., Homeier, D., ...
A test case comparison is presented for different dust cloud model approaches applied in brown dwarfs and giant gas planets. We aim to achieve more transparency in evaluating the uncertainty inherent...
A very cool brown dwarf in UKIDSS DR1 (2007)
Warren, S. J., Mortlock, D. J., Leggett, S. K., Pinfield, D. J., Homeier, D., Dye, S., ...
(abridged) We report the discovery of a very cool brown dwarf, ULAS J003402.77-005206.7 (ULAS J0034-00), identified in UKIDSS DR1. We provide optical, near-infrared, and mid-infrared photometry of...
A high resolution spectral atlas of brown dwarfs (2007)
Reiners, A., Homeier, D., Hauschildt, P. H., Allard, F.
We present a UVES/VLT high resolution atlas of three L dwarfs and one T dwarf system, spectral classes at which most of the objects are brown dwarfs. Our atlas covers the optical region from...
Six New ZZ Ceti Stars from the SPY and the HQS Surveys (2007)
Voss, B., Koester, D., Østensen, R., Napiwotzki, R., Homeier, D., Reimers, D.
We report on the discovery of six new ZZ Ceti stars. They were selected as candidates based on preparatory photometric observations of objects from the Hamburg Quasar Survey (HQS), and based on the...
Investigation of transit-selected exoplanet candidates from the MACHO survey (2007)
Huegelmeyer, S. D., Dreizler, S., Homeier, D., Reiners, A.
Context: Planets outside our solar system transiting their host star, i. e. those with an orbital inclination near 90 degree, are of special interest to derive physical properties of extrasolar...
Spectral types of planetary host star candidates from OGLE III (2007)
Dreizler, S., Schuh, S., Homeier, D.
The Optical Gravitational Lensing Experiment project has recently provided the OGLE III list of low-luminosity object transits from campaigns #3 and #4, reporting 40 new objects exhibiting the...
A very cool brown dwarf in UKIDSS DR1. (2007)
Warren, S.J., Mortlock, D.J., Leggett, S., Pinfield, D.J., Homeier, D., Dye, S., ...
Binary White Dwarfs in the Supernova Ia Progenitor Survey. (2007)
Napiwotzki, R., Karl, C., Nelemans, G., Yungelson, L., Christlieb, N., Drechsel, H., ...
Six New ZZ Ceti Stars from the SPY and the HQS Surveys. (2007)
Voss, B., Koester, D., Ostensen, R., Napiwotzki, R., Homeier, D., Reimers, D.
Huegelmeyer, S. D., Dreizler, S., Homeier, D., Krzesinski, J., Werner, K., Nitta, A., ...
Context: The Sloan Digital Sky Survey Data Release 4 has provided spectra of several new PG 1159 stars and DO white dwarfs. This increase in known hot H-deficient compact objects significantly...
Discovery of seven ZZ Ceti stars using a new photometric selection method. (2006)
Voss, B., Koester, D., Ostensen, R., Kepler, S.O., Napiwotzki, R., Homeier, D., ...
HS 0146 1847 - a DAZB white dwarf of very unusual composition (2005)
Koester, D., Napiwotzki, R., Voss, B., Homeier, D., Reimers, D.
Two new ZZ Ceti pulsators from the HS and HE surveys (2005)
Silvotti, R., Voss, B., Bruni, I., Koester, D., Reimers, D., Napiwotzki, R., ...
We report the detection of nonradial g-mode oscillations in the DA white dwarfs HS1039+4112 (B=15.9) and HE1429-0343 (B=15.8) from time-series photometry made at the Loiano 1.5 m telescope. The two...
Metal traces in white dwarfs of the SPY (ESO Supernova Ia Progenitor Survey) sample (2005)
Koester, D., Rollenhagen, K., Napiwotzki, R., Voss, B., Christlieb, N., Homeier, D., ...
Metal traces in white dwarfs of the SPY (ESO Supernova Ia Progenitor Survey) sample (2005)
Koester, D., Rollenhagen, K., Napiwotzki, R., Voss, B., Christenlieb, N., Homeier, D., ...
Two new ZZ Ceti pulsators from the HS and HE surveys. (2005)
Silvotti, R., Voss, B., Bruni, I., Koester, D., Reimers, D., Napiwotzki, R., ...
DAZ White Dwarfs in the SPY Sample. (2005)
Koester, D., Rollenhagen, K., Napiwotzki, R., Voss, B., Christlieb, N., Homeier, D., ...
Subdwarf B Stars from the ESO Supernova Ia Progenitor Survey -- Observation versus Theory. (2005)
Lisker, T., Heber, U., Napiwotzki, R., Christlieb, N., Han, Z., Homeier, D., ...
New Results from the Supernova Ia Progenitor Survey. (2005)
Napiwotzki, R., Karl, C., Nelemans, G., Yungelson, L., Christlieb, N., Drechsel, H., ...
Lisker, T., Heber, U., Napiwotzki, R., Christlieb, N., Han, Z., Homeier, D., ...
We present the analysis of a high-resolution, high-quality sample of optical spectra for 76 subdwarf B (sdB) stars from the ESO Supernova Ia Progenitor Survey (SPY). Effective temperature, surface...
Close binary EHB stars from SPY (2004)
Napiwotzki, R., Karl, C., Lisker, T., Heber, U., Christlieb, N., Reimers, D., ...
Close binary EHB stars from SPY (2004)
Napiwotzki, R., Karl, C. A., Lisker, T., Heber, U., Christlieb, N., Reimers, D., ...
We present the results of a radial velocity (RV) survey of 46 subdwarf B (sdB) and 23 helium-rich subdwarf O (He-sdO) stars. We detected 18 (39%) new sdB binary systems, but only one (4%) He-sdO...
Close binary white dwarfs and supernovae IA (2004)
Christlieb , N., Drechsel , H., Heber , U., Homeier , D., Karl , C., Koester , D., ...
Informamos sobre el estado actual de los surveys" de velocidades radiales para binarias de enanas blancas (degeneradas dobles - DDs) incluyendo SPY (Exploración ESO de progenitoras de supernovas Ia)...
Spectroscopic analysis of sdB stars from the ESO Supernova Ia Progenitor Survey (2004)
Lisker, T., Heber, U., Napiwotzki, R., Christlieb, N., Han, Z., Homeier, D., ...
Double Degenerate and Progenitors of Supernovae Type Ia. (2004)
Napiwotzki, R., Yungelson, L., Nelemans, G., Marsh, T.R., Leibundgut, B., Renzini, A., ...
Spectroscopic analysis of sdB stars from the ESO Supernova Ia Progenitor Survey (2003)
Lisker, T., Heber, U., Napiwotzki, R., Christlieb, N., Reimers, D., Homeier, D.
We report on the analysis of high-resolution optical spectra for 77 subdwarf B (sdB) stars from the ESO Supernova Ia Progenitor Survey. Effective temperature, surface gravity, and photospheric helium...
Search for double degenerate progenitors of supernovae type Ia with SPY (2002)
Napiwotzki, R., Christlieb, N., Drechsel, H., Heber, U., Homeier, D., ...
We report on a large survey for double degenerate (DD) binaries as potential progenitors of type Ia supernovae with the UVES spectrograph at the ESO VLT (SN Ia Progenitor surveY - SPY). About 560...
Search for double degenerate progenitors of supernovae type Ia with SPY (2002)
Napiwotzki, R., Drechsel, H., Heber, U., Karl, C., Christlieb, N., ...
We report on a large survey for double degenerate (DD) binaries as potential progenitors of type Ia supernovae with the UVES spectrograph at the ESO VLT (ESO SN Ia Progenitor surveY - SPY).
Methane Opacities in T Dwarf Atmospheres (2002)
Homeier, D., Hauschildt, P. H., Allard, F.
We present the current status of PHOENIX model atmospheres for dwarfs of the spectral type T, typical for older field brown dwarfs and low-mass brown dwarfs. The results are based on new predictions...
Search for progenitors of supnernovae type Ia with SPY (2002)
Napiwotzki, R., Christlieb, N., Drechsel, H., Heber, U., Homeier, D., ...
We have started a large survey for double degenerate (DD) binaries as potential progenitors of type Ia supernovae with the UVES spectrograph at the ESO VLT (ESO SN Ia Progenitor surveY - SPY). About...
Search for progenitors of supernovae type Ia with SPY (2001)
Napiwotzki, R., Christlieb, N., Drechsel, H., Heber, U., Homeier, D., ...
Search for progenitors of supernovae type Ia with SPY. (2001)
Napiwotzki, R., Christlieb, N., Drechsel, H., Hagen, H.J., Heber, U., Homeier, D., ...
‘The definitive version is available at www3.interscience.wiley.com .' Copyright WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim DOI: 10.1002/1521-3994(200112)322:5/63.0.CO;2-I [Full text of this...
The stellar content of the Hamburg/ESO survey. I. Automated selection of DA white dwarfs (2000)
Christlieb, N., Wisotzki, L., Reimers, D., Homeier, D., Koester, D., Heber, U.
We describe automatic procedures for the selection of DA white dwarfs in the Hamburg/ESO objective-prism survey (HES). For this purpose, and the selection of other stellar objects (e.g., metal-poor...
D. Homeier, K. Jansen, D. Mesterhazy, C. Urbach
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