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Long-Term Optical Monitoring of Eta Carinae. Multiband light curves for a complete orbital period
E. Fernandez-Lajus, C. Farina, A. F. Torres +8
The periodicity of 5.5 years for some observational events occurring in Eta Carinae manifests itself across a large wavelength range and has been associated with its binary nature.…
The very massive X-ray bright binary system Wack 2134 (= WR 21a)
V. S. Niemela, R. C. Gamen, R. H. Barba +5
From the radial velocities of the N IV 4058 and He II 4686 emission lines, and the N V 4604-20 absorption lines, determined in digital spectra, we report the discovery that the X-r…
Discovery of a [WO] central star in the planetary nebula Th 2-A
W. A. Weidmann, R. Gamen, R. J. Diaz +1
% context About 2500 planetary nebulae are known in our Galaxy but only 224 have central stars with reported spectral types in the Strasbourg-ESO Catalogue of Galactic Planetary Ne…
The periodicity of the eta Carinae events
A. Damineli, M. F. Corcoran, D. J. Hillier +14
Extensive spectral observations of eta Carinae over the last cycle, and particularly around the 2003.5 low excitation event, have been obtained. The variability of both narrow and…
The stellar upper mass limit in the solar neighborhood
J. Maíz Apellániz, Nolan R. Walborn, N. I. Morrell +4
We are using HST GO programs 10205, 10602, and 10898 to test the stellar upper mass limit in the solar vicinity by attempting to detect optical close companions, thus lowering the…
Pismis 24-1: The Stellar Upper Mass Limit Preserved
J. Maíz Apellániz, Nolan R. Walborn, N. I. Morrell +2
Is there a stellar upper mass limit? Recent statistical work seems to indicate that there is and that it is in the vicinity of 150 solar masses. In this paper we use HST and ground…
The first orbital solution for the massive colliding-wind binary HD93162 (=WR25)
R. Gamen, E. Gosset, N. Morrell +6
Since the discovery, with the EINSTEIN satellite, of strong X-ray emission associated with HD93162 (=WR25), this object has been predicted to be a colliding-wind binary system. How…
Optical Spectroscopy of X-Mega targets in the Carina Nebula - VI. FO 15: a new O-Type double-lined eclipsing binary
V. S. Niemela, N. I. Morrell, E. Fernandez Lajus +3
We report the discovery of a new O-type double-lined spectroscopic binary with a short orbital period of 1.4 days. We find the primary component of this binary, FO 15, to have an a…
Observing campaign of Eta Carinae from La Plata. Period 2003-2004
E. Fernandez Lajus, C. Fariña, R. Gamen +6
After the Observing Campaign of Eta Carinae carried out during 2003, we have continued the CCD observations using the 0.8 m Reflector telescope at La Plata Observatory, in the BVRI…
The Nearest Star of spectral type O3: A Component of the Multiple System HD 150136
V. S. Niemela, R. C. Gamen
From radial velocities determined in high signal-to-noise digital spectra, we report the discovery that the brightest component of the binary system HD 150136 is of spectral type O…
Hubble Space Telescope Imaging of the WR 38/WR38a Cluster
Debra J. Wallace, Douglas R. Gies, Anthony F. J. Moffat +2
We are conducting a high angular resolution imaging survey of Galactic Wolf-Rayet stars using the Wide Field and Planetary Camera 2 aboard the Hubble Space Telescope. We have found…
Optical CCD Observations of Eta Carinae at La Plata Observatory
E. Fernandez Lajus, R. Gamen, M. Schwartz +5
In 2003.5 Eta Carinae was expected to undergo an X-ray eclipse (Damineli et al., 2000). In the framework of an international campaign to obtain multi-wavelength observations of thi…
LSS 1135: an O-Type Spectroscopic Binary in the galactic OB association Bochum 7
Mariela Corti, Virpi Niemela, Nidia Morrell
From radial velocities derived from optical spectroscopic observations performed at CTIO, Chile, and CASLEO, Argentina, we have discovered that LSS 1135 is a single--lined O-type b…
An X-ray investigation of the NGC346 field in the SMC (1) : the LBV HD5980 and the NGC346 cluster
Y. Naze, J. M. Hartwell, I. R. Stevens +5
We present results from a Chandra observation of the NGC346 cluster. This cluster contains numerous massive stars and is responsible for the ionization of N66, the most luminous HI…
The orbit of the double-lined Wolf-Rayet Binary HDE 318016 (= WR98)
Roberto C. Gamen, Virpi S. Niemela
We present the discovery of OB type absorption lines superimposed to the emission line spectrum and the first double-lined orbital elements for the massive Wolf-Rayet binary HDE 31…
The Massive Wolf-Rayet Binary HDE318016 (=WR 98)
Roberto C. Gamen, Virpi S. Niemela
We present the discovery of OB type absorption lines superimposed to the emission line spectrum, and the first double-lined orbital elements for the massive Wolf-Rayet binary HDE 3…
The Massive Wolf-Rayet Binary SMC WR7
V. S. Niemela, P. Massey, G. Testor +1
We present a study of optical spectra of the Wolf--Rayet star AzV 336a (= SMC WR7) in the Small Magellanic Cloud. Our study is based on data obtained at several Observatories betwe…
Spatially resolved STIS spectra of WR+OB binaries with colliding winds
Sebastien Lepine, Debra Wallace, Michael M. Shara +2
We present spatially resolved spectra of the visual WR+OB massive binaries WR86, WR146, and WR147, obtained with the Space Telescope Imaging Spectrograph on board the Hubble Space…
Optical spectroscopy of X-Mega targets in the Carina Nebula. II. The massive double-lined O-type binary HD 93205
N. I. Morrell, R. H. Barba, V. S. Niemela +8
A new high-quality set of orbital parameters for the O-type spectroscopic binary HD93205 has been obtained combining echelle and coude CCD observations. The radial velocity orbits…
The highly polarized open cluster Trumpler 27
Carlos Feinstein, Gustavo Baume, Ruben Vazquez +2
We have carried out multicolor linear polarimetry (UBVRI) of the brightest stars in the area of the open cluster Trumpler 27. Our data show a high level of polarization in the stel…