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Infrared standards for ISO. I. A new calibration of mid infrared photometry
Kessler, M. F.; Bouchet, P.; Metcalfe, L. +5 more
We present N, 8.7 mu m, 9.8 mu m 12.5 mu m and Q bolometry of 26 stars which were observed on the IRTF. These are primarily K giants which have been well measured at other wavelengths and are chosen to be single and non-variable. Hence the data presented provides a new homogeneous set of mid IR standards. As a test of part of the calibration strat…
Spectral decomposition by genetic forward modelling
Judge, P. G.; Brown, J. C.; Charbonneau, P. +3 more
We discuss the analysis of real and simulated line spectra using a genetic forward modelling technique. We show that this Genetic Algorithm (GA) based technique experiences none of the user bias or systematic problems that arise when faced with poorly sampled or noisy data. An important feature of this technique is the ease with which rigid a prio…
Multiplicity among peculiar A stars. I. The AP stars HD 8441 and HD 137909, and the AM stars HD 43478 and HD 96391
Carrier, F.; Udry, S.; North, P. +2 more
We present the first results of a radial-velocity survey of cool Ap and Am stars. HD 8441 is not only a double system with P = 106.357 days, but is a triple one, the third companion having an orbital period larger than 5000 days. Improved orbital elements are given for the classical Ap star HD 137909 = beta CrB by combining our radial velocities w…
Numerical simulation of observations with GOLF on board SOHO
Roca Cortes, T.; Garcia, R. A.; Regulo, C.
The main objective of the GOLF Experiment (Global Oscillations at Low Frequencies) on-board the SOHO (Solar and Heliospheric Observatory) space mission is the quantitative knowledge of the internal structure of the Sun by measuring the spectrum of its global oscillations in a wide frequency range (30 nHz to 6 mHz). There is special interest in det…
The Arcetri spectral code for thin plasmas
Landini, M.; Landi, E.
The Arcetri spectral code allows to evaluate the spectrum of the radiation emitted by hot and optically thin plasmas in the spectral range 1 - 2000 Angstroms. The database has been updated including atomic data and radiative and collisional rates to calculate level population and line emissivities for a number of ions of the minor elements; a crit…
UV turn-off times of classical novae
Gallagher, J.; Orio, M.; Gonzalez-Riestra, R.
We present IUE spectra of classical novae obtained at least one year after the outburst. The UV luminosities are compared with the ROSAT\ observations and significant parameters of the systems. The turn-off times derived from the IUE data are in agreement with the ROSAT\ results, showing that most novae decline in bolometric luminosity 1-5 years a…
The photosphere and chromosphere of the RS Canum Venaticorum star, II Pegasi. II. A multi-wavelength campaign in August/September 1992
Amado, P. J.; Doyle, J. G.; Sarro, L. M. +14 more
We describe multi-wavelength, simultaneous observations of the RS CVn star, II Pegasi, most of which were obtained during the first three weeks of September 1992. These observations were made using optical and infra-red broad-band photometry, ultraviolet and optical spectroscopy and microwave monitoring. We have detected photospheric spots and chr…
UVBY photometry of 33 Tauri, HD 50169, and HR 7786 and an assessment of FCAPT comparison stars
Adelman, S. J.; Pi, C. -L. M.; Rayle, K. E.
Differential Strömgren uvby photometric observations from the Four College Automated Photoelectric Telescope are presented for the ellipsoidal variable 33 Tauri, and the magnetic Chemically Peculiar stars HD 50169 and HR 7786. We confirm that Hube's period of 2.975272 days for 33 Tau is correct. HD 50169 is a constant MCP star. HR 7786 is a large …
The art of fitting p-mode spectra. II. Leakage and noise covariance matrices
Appourchaux, T.; Gizon, L.; Rabello-Soares, M. -C.
In Part I we have developed a theory for fitting p-mode Fourier spectra assuming that these spectra have a multi-normal distribution. We showed, using Monte-Carlo simulations, how one can obtain p-mode parameters using ``Maximum Likelihood Estimators". In this article, hereafter Part II, we show how to use the theory developed in Part I for fittin…
F, G and K stars in the ROSAT all-sky survey. I. Photometry
Pasquini, L.; Krautter, J.; Cutispoto, G. +2 more
We present accurate BV(RI)_c photometry for a sample of F, G and K stars detected in selected areas of the ROSAT all-sky survey (RASS). We have used the photometry, in addition to low-resolution spectroscopy, to estimate spectral classifications, distances and X-ray luminosities. The log (L_X / L_V) in the sample lies below -2. Although the sample…