The periodicity of the Eta Carinae events

Autor: Virpi S. Niemela, Otmar Stahl, F. Gonzalez, M. Teodoro, Mónica Grosso, Augusto Damineli, J. F. Albacete Colombo, D. J. Hillier, Jose H. Groh, Nidia Morrell, Nelson Vani Leister, George Wallerstein, R. S. Levenhagen, Julia Ines Arias, Michael F. Corcoran, Roberto Claudio Gamen, Hugo Levato

Publikováno v: RID-UNRN (UNRN)
Universidad Nacional de Río Negro
instacron:UNRN
CONICET Digital (CONICET)
Consejo Nacional de Investigaciones Científicas y Técnicas
instacron:CONICET
SEDICI (UNLP)
Universidad Nacional de La Plata
instacron:UNLP

Extensive spectral observations of η Carinae over the last cycle, and particularly around the 2003.5 low-excitation event, have been obtained. The variability of both narrow and broad lines, when combined with data taken from two earlier cycles, rev

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::b0a31fa24e6bcd88da4b57da285b8d74
https://rid.unrn.edu.ar/jspui/handle/20.500.12049/2505

The interstellar medium in the Upper Cepheus-Cassiopeia region

Autor: C. A. Olano, Virpi S. Niemela, P. I. Meschin

Publikováno v: Monthly Notices of the Royal Astronomical Society. 369:867-874

We have studied the kinematics and spatial distribution of the interstellar gas in the sky region 110° ≤l≤ 135°, 10° ≤ b ≤ 20°, using the extensive Leiden-Dwingeloo Survey of H I emission and the Columbia Survey of CO emission. The spectr

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::97fdabc459b409c14b9ec401e7e151d7
https://doi.org/10.1111/j.1365-2966.2006.10343.x

Massive spectroscopic binaries in the Magellanic Clouds

Autor: Roberto Claudio Gamen, Virpi S. Niemela

Publikováno v: New Astronomy Reviews. 48:727-730

We present results of our ongoing observing program on search and studies of massive stars (O type) in binary systems in our neighbour galaxies, the Magellanic Clouds. Radial velocity orbits are presented for two new binaries, one in the Small Magell

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::2253cc31bbdf11a0c701e38511686cc8
https://doi.org/10.1016/j.newar.2004.03.008

Magellanic Cloud WC/WO Wolf-Rayet stars - II. Colliding winds in binaries

Autor: Virpi S. Niemela, P. Bartzakos, A. F. J. Moffat

Publikováno v: SEDICI (UNLP)
Universidad Nacional de La Plata
instacron:UNLP

A search for evidence of colliding winds is undertaken among the four certain Magellanic Cloud WC/WO spectroscopic binaries found in the companion Paper I, as well as among two Galactic WC/WO binaries of very similar subtype. Two methods of analysis,

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::b3abd9f46c7f5f673020fea7d465c45b
https://doi.org/10.1046/j.1365-8711.2001.04127.x

Hubble Space TelescopeObservations of the Luminous Blue Variable/W‐R Eclipsing Binary System HD 5980

Autor: Gloria Koenigsberger, L. Georgiev, Zlatan Tzvetanov, Nolan R. Walborn, Nidia Morrell, Virpi S. Niemela, Regina E. Schulte-Ladbeck, Rodolfo H. Barbá

Publikováno v: The Astrophysical Journal. 542:428-445

We report the results of Hubble Space Telescope STIS observations of the intriguing luminous blue variable/Wolf-Rayet binary system HD 5980 in the Small Magellanic Cloud. Although its spectral char- acteristics (WN6) are currently very similar to tho

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::ef24904103b7d37999ccfd07a9d62cda
https://doi.org/10.1086/309529