Publications (24)
Spectroscopic and photometric analysis of the early-type spectroscopic binary HD 161853 in the centre of an H II region
R. Gamen, C. Putkuri, N. I. Morrell +6
We study the O-type star HD 161853, which has been noted as a probable double-lined spectroscopic binary system. We secured high-resolution spectra of HD 161853 during the past nin…
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 new Wolf-Rayet binary system WR62a
A. Collado, R. Gamen, R. H. Barbá
Context. A significant number of the Wolf-Rayet stars seem to be binary or multiple systems, but the nature of many of them is still unknown. Dedicated monitoring of WR stars favou…
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…
Discovery of a deep Seyfert-2 galaxy at z = 0.222 behind NGC 300
J. A. Combi, F. Garcia, M. J. Rodriguez +2
We report on the unveiling of the nature of the unidentified X-ray source 3XMM J005450.3-373849 as a Seyfert-2 galaxy located behind the spiral galaxy NGC 300 using Hubble Space Te…
Near-infrared photometry of Galactic planetary nebulae with the VVV Survey
W. A. Weidmann, R. Gamen, P. A. M. van Hoof +3
Planetary nebulae (PNe) are powerful tracers of evolved stellar populations. Among the 3000 known PNe in the Galaxy, about 600 are located within the 520 square-degree area covered…
Non-synchronous rotations in massive binary systems. HD93343 revisited
C. Putkuri, R. Gamen, N. I. Morrell +5
Context. Most massive stars are in binary or multiple systems. Several massive stars have been detected as doublelined spectroscopic binaries and among these, the OWN Survey has de…
Estrellas Wolf-Rayet de tipo WN en La VÃa Láctea: Campaña 2007-2008
A. Collado, R. Gamen, R. Barbá
We are carrying out a spectroscopic monitoring of Galactic Wolf-Rayet stars, in order to detect binary systems. The sample consists of approximately 50 stars of the Nitrogen sequen…
A remarkable change of the spectrum of the magnetic Of?p star HD 148937 reveals evidence of an eccentric, high-mass binary
G. A. Wade, J. V. Smoker, C. J. Evans +10
We report new spectroscopic observations of the magnetic Of?p star HD 148937 obtained since 2015 that differ qualitatively from its extensive historical record of weak, periodic sp…
A new massive double-lined spectroscopic binary system: The Wolf-Rayet star WR 68a
A. Collado, R. Gamen, R. H. Barbá +1
Double-lined spectroscopic binary systems, containing a Wolf-Rayet and a massive O-type star, are key objects for the study of massive star evolution because these kinds of systems…
The IACOB project: XVI. Surface helium abundances in Galactic O-type stars: indications for identifying binary interaction products
S. Simón-DÃaz, G. Holgado, C. MartÃnez-Sebastián +13
The presence of massive O-type stars with surfaces enriched by CNO-cycle products has been known since the early 1980s. For many years, internal rotational mixing was assumed to be…
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…
A multispectral view of the periodic events in eta Carinae
A. Damineli, D. J. Hillier, M. F. Corcoran +13
A full description of the 5.5-yr low excitation events in Eta Carinae is presented. We show that they are not as simple and brief as previously thought, but a combination of two co…
Catalogue of central stars of planetary nebulae: Expanded edition
W. A. Weidmann, M. B. Mari, E. O. Schmidt +7
Planetary nebulae represent a potential late stage of stellar evolution, however the central stars (CSPNe) are relatively faint and therefore pertinent information is merely availa…
Stellar populations in the Carina region: The Galactic plane at l = 291
J. A. Molina-Lera, G. Baume, R. Gamen +2
Previous studies of the Carina region have revealed its complexity and richness as well as a significant number of early-type stars. In many cases, these studies only concentrated…
Rotation, spectral variability, magnetic geometry and magnetosphere of the Of?p star CPD -28 2561
G. A. Wade, R. H. Barbá, J. Grunhut +14
We report magnetic and spectroscopic observations and modeling of the Of?p star CPD -28 2561. Using more than 75 new spectra, we have measured the equivalent width variations and e…
Spectroscopic monitoring of Southern Galactic O and WN stars: State of the Art in 2007
R. Gamen, R. Barba, N. Morrell +5
We are conducting a spectroscopic monitoring of O and WN -type stars in our Galaxy. In this work, we summarize some of our first results related to the search for radial-velocity v…
The eccentric short-period orbit of the supergiant fast X-ray transient HD 74194 (=LM Vel)
R. Gamen, R. H. Barbá, N. R. Walborn +5
Aims. We present the first orbital solution for the O-type supergiant star HD 74194, which is the optical counterpart of the supergiant fast X-ray transient IGR J08408-4503. Method…
The IACOB project XVIII. Prevalence of short-period binaries among Galactic helium rich O-type stars
C. Martínez-Sebastián, R. Gamen, O. G. Benvenuto +6
For decades, the origin of helium enrichment in O-type stars has remained an open question. In this study, we investigate the correlation between surface helium abundance and orbit…
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…
Towards an improvement in the spectral description of central stars of planetary nebulae
W. Weidmann, R. Gamen, D. Mast +7
Context. There are more than 3000 known Galactic planetary nebulae (PNe), but only 492 central stars of Galactic planetary nebulae (CSPN) have known spectral types. It is vital to…
Apsidal motion in massive close binary systems. I. HD 165052 an extreme case?
G. Ferrero, R. Gamen, O. G. Benvenuto +1
We present a new set of radial-velocity measurements of the spectroscopic binary HD 165052 obtained by disentangling of high-resolution optical spectra. The longitude of the perias…
Southern near-infrared photometric monitoring of Galactic young star clusters (NIP of Stars)
R. Barbá, N. Morrell, G. Gunthardt +8
We have performed a near-infrared photometric monitoring of 39 galactic young star clusters and star-forming regions, known as {\em NIP of Stars}, between the years 2009--2011, usi…
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…