Search Publications
A photometric study of the recently discovered eclipsing binary V899 Herculis
Bulut, İ.; Demircan, O.; Soydugan, F. +4 more
The radial velocity and UBV light curves of V899 Her as found in the literature were studied for the first time to obtain the orbital parameters and geometry of the system. The solutions obtained by using the Wilson-Devinney code reveal an over-contact system with a fill-out factor of 23.7%. This solution is only possible with a large amount of th…
The 3 mu m spectrum of R Doradus observed with the ISO-SWS
Ryde, N.; Eriksson, K.
We have modeled the 2.6-3.7 µm spectrum of the red semiregular variable R Doradus observed with the Short-Wavelength Spectrometer on board the Infrared Space Observatory. The wavelength resolution of the observations varies between R ~ 2000-2500. We have calculated a synthetic spectrum using a hydrostatic model photosphere in spherical geome…
FUSE observations towards the pole-on Be star HR 5223
Frémat, Y.; Zorec, J.; Ferlet, R. +5 more
New spectra have been obtained for the pole-on Be star HR 5223 (HD 120991) using the Far Ultraviolet Satellite Explorer (FUSE). We give a complete description of the far-UV spectral range (920 to 1180 Å). The spectra are affected by strong blends with interstellar lines and molecular bands that also significantly lower the energy distribution of t…
Infrared emission towards SN 1987A 11 years after outburst: Measurements with ISOCAM
Völk, H. J.; Tuffs, R. J.; Fischera, Jg.
We present measurements of the mid-infrared (MIR) emission from SN 1987A, made using the Infrared Space Observatory (ISO) 11 years after outburst. They are the only late epoch detections of this source in the thermal IR regime. The position of the source, determined from an offset to an IR-emitting star, suggests that the emission is associated wi…
New binary stars discovered by lunar occultations. VI.
Stecklum, B.; Richichi, A.; Calamai, G.
We present additional results from our ongoing lunar occultation program. Observations are presented here for a total of seventeen sources, for the majority of which one or two new companions are detected. The sample comprises mostly field stars, spanning a large range of spectral types. Two infrared objects without optical counterpart are also in…
Models for solar magnetic loops. I. A simple theoretical model and diagnostic procedure
Landini, M.; Landi, E.
In the present paper the quasi-static model of Landini & Monsignori Fossi (\cite{Landini75}) for coronal loops is improved and a simple diagnostic procedure is developed to compare the most important physical properties of the model with a set of spectral observations of loops such as those obtained by the CDS and SUMER instruments on SOHO. Th…
The origin of the anomalous intensity ratio between very bright UV FeII lines and their satellites in gaseous condensations close to the star eta Carinae
Johansson, S.; Letokhov, V. S.; Klimov, V.
We present a model that explains the anomalous intensity ratios between each of two very bright UV lines of Fe II at 2507 Å and 2509 Å and its corresponding satellite line, observed in HST spectra of a compact gaseous condensation (blob B) in the vicinity of the star protect eta Car.The model is based on the assumption that the FeII transitions ha…
An unusual iron Lo-BAL quasar detected by ISOCAM
Elbaz, D.; Cesarsky, C.; Duc, P. -A. +10 more
We report the discovery of an unusual low-ionization broad absorption line quasar at z=1.776 which exhibits absorption lines from many excited states of Fe II. This member of the rare class of ``FeLoBAL'' quasars was serendipitously found in a mid-infrared (MIR) survey of distant clusters carried out with the ISOCAM camera. ISO J005645.1-273816 ha…
Star formation in the warped outer pseudoring of the spiral galaxy NGC 3642
Bosma, A.; Athanassoula, E.; Verdes-Montenegro, L.
NGC 3642 was classified as a spiral galaxy with three rings and no bar. We have performed an HI and optical study of this nearly face-on galaxy. We find that the nuclear ring might in fact be part of an inner one-armed spiral, that could be driving nuclear accretion and feeding the central activity in the inner kpc. The inner ring is faint, and th…
Detectability and characteristics of the 2.223 MeV line emission from nearby X-ray binaries
Guessoum, N.; Jean, P.
We present an application and an improvement of the model of Jean & Guessoum (\cite{JG01}) for the production of the 2.223 MeV line resulting from the capture of neutrons in the atmosphere of the secondary in an X-ray binary system. In this model, the neutrons are produced in the accretion disk around the compact primary star and radiated in a…