Rauw, Grégor, Naze, Yaël, Fernández Lajús, E, Lanotte, Audrey, Solivella, G R, Sana, H, ...
We present the results of a spectroscopic monitoring campaign devoted to three O-type stars in the Carina nebula. We derive the full SB2 orbital solution of the binary system Tr16-112, an exceptional...
Mahy, Laurent, Naze, Yaël, Rauw, Grégor, Gosset, Eric, De Becker, Michaël, Sana, H, ...
Aims. We present the results obtained from a long-term spectroscopic campaign to study the multiplicity of O-type stars in both the young open cluster NGC 2244 and the Mon OB2 association. Methods:...
The X-ray stellar population of the LMC (2009)
The Magellanic System: Stars, Gas, and Galaxies, IAU S256
The Gaia satellite: a tool for Emission Line Stars and Hot Stars (2008)
Martayan, C, Frémat, Y, Blomme, R, Jonckheere, A, Borges, M, De Batz, B, ...
The Gaia satellite will be launched at the end of 2011. It will observe at least 1 billion stars, and among them several million emission line stars and hot stars. Gaia will provide parallaxes for...
Towards an Understanding of the Of?p star HD 191612: Optical Spectroscopy (2008)
Howarth, I D, Walborn, N R, Lennon, D J, Puls, J, Naze, Yaël
We have acquired extensive optical spectroscopy of the early-type magnetic star HD 191612 (O6.5f?pe-O8fp). The Balmer and HeI lines show strongly variable emission which is extremely reproducible on...
The first orbital solution for the massive colliding-wind binary HD 93162 (= WR 25) (2008)
Gamen, R, Gosset, Eric, Morrell, N I, Niemela, V S, Sana, H, Naze, Yaël, ...
Since the discovery, with EINSTEIN, of strong X-ray emission associated with HD 93162, this object was recurrently predicted by some authors to be a colliding-wind binary system. However,...
Townsend, Rich, Cohen, David H, Dessart, Luc, Hubrig, Swetlana, Naze, Yaël, Petit, Véronique, ...
Magnetic fields are unexpected in massive stars, due to the absence of a sub-surface convective dynamo. However, advances in instrumentation over the past three decades have led to their detection in...
EuroPlaNet: Improving the Communication on Planetary Sciences (2008)
EuroPlaNet is an EC-funded consortium. It coordinates the activities of European researchers working in planetary sciences but it is not only aimed at pure scientific activities. Its outreach action...
A binary signature in the non-thermal radio-emitter Cyg OB2 #9 (2008)
Naze, Yaël, De Becker, Michaël, Rauw, Grégor, Barbieri, Cesare
Aims. Non-thermal radio emission associated with massive stars is believed to arise from a wind-wind collision in a binary system. However, the evidence of binarity is still lacking in some cases,...
The mysterious Of?p class and the magnetic O-star theta(1) Ori C: Confronting observations (2008)
Naze, Yaël, Walborn, Nolan R., Martins, Fabrice
In recent years, the stars of the Of?p category have revealed a wealth of peculiar phenomena: varying line profiles, photometric changes, and X-ray over-luminosity are only a few of their...
The massive star binary fraction in young open clusters - I. NGC 6231 revisited (2008)
Sana, H, Gosset, Eric, Naze, Yaël, Rauw, Grégor, Linder, Natacha
We present the results of a long-term high-resolution spectroscopy campaign on the O-type stars in NGC 6231. We revise the spectral classification and multiplicity of these objects and we constrain...
New insights into the nature of the SMC WR/LBV binary HD 5980 (2008)
Foellmi, C, Koenigsberger, G, Georgiev, L, Toledano, O, Marchenko, S V, Massey, P, ...
We present the results of optical wavelength observations of the unusual SMC eclipsing binary system HD 5980 obtained in 1999 and 2004-2005. Radial velocity curves for the erupting LBV/WR object...
X-ray spectroscopy of early-type stars: The present and the future (2008)
Rauw, Grégor, Naze, Yaël, Oskinova, L M
XMM-Newton and Chandra have boosted our knowledge about the X-ray emission of early-type stars (spectral types OB and Wolf-Rayet). However, there are still a number of open questions that need to be...
The massive binary HD 152218 revisited: A new colliding wind system in NGC 6231 (2008)
Sana, H, Naze, Yaël, O'Donnell, B, Rauw, Grégor, Gosset, Eric
We present the results of an optical and X-ray monitoring campaign on the short-period massive SB2 binary HD 152218. Combining our HiRes spectroscopic data with previous observations, we unveil the...
High-resolution X-ray spectroscopy of theta Carinae (2008)
Context. The peculiar hot star. Car in the open cluster IC2602 is a blue straggler as well as a single-line binary with a short period (2.2d). Aims. Its high-energy properties are not well known,...
Naze, Yaël, Rauw, Grégor, Manfroid, Jean
Context. Westerlund 2 is a young and massive, obscured stellar cluster of our Galaxy. It harbors the most massive star with well-determined parameters, WR20a (82 + 83 M-circle dot), a dozen very...
HD 148937: A multiwavelength study of the third galactic member of the Of?p class (2008)
Naze, Yaël, Walborn, Nolan R., Rauw, Grégor, Martins, Fabrice, Pollock, A. M. T., Bond, Howard E.
Three Galactic O-type stars belong to the rare class of Of? p objects: HD 108, HD 191612, and HD 148937. The first two stars show a wealth of phenomena, including strong X-ray emission, light...
Spectroscopic and photometric variability of the O9.5Vp star HD93521 (2008)
Rauw, Grégor, De Becker, Michaël, Van Winckel, Hans, Aerts, Conny, Eenens, Philippe, Lefever, Karolien, ...
Aims. The line profile variability and photometric variability of the O9.5Vp star HD93521 are examined in order to establish the properties of the non-radial pulsations in this star. Methods. Fourier...
Towards an understanding of the Of ? p star HD 191612: optical spectroscopy (2007)
Howarth, Ian D., Walborn, Nolan R., Lennon, Danny J., Puls, Joachim, Naze, Yaël, Annuk, K, ...
We present extensive optical spectroscopy of the early-type magnetic star HD 191612 (O6.5f ? pe-O8fp). The Balmer and He i lines show strongly variable emission which is highly reproducible on a...
Long-term Spectroscopic Variability of Two Oe Stars (2007)
Rauw, Grégor, Naze, Yaël, Marique, PX, De Becker, Michaël, Sana, Hugues, Vreux, Jean-Marie
HD 45314 and HD 60848 are poorly studied Oe-type stars. Spectroscopic monitoring over 5 years reveals strong variations in the strength of the emission lines and for HD 45314 in the V/R ratio of the...
First detection of phase-dependent colliding wind X-ray emission outside the Milky Way (2007)
Naze, Yaël, Corcoran, MF, Koenigsberger, G, Moffat, AFJ
After having reported the detection of X-rays emitted by the peculiar system HD 5980, we assess here the origin of this high-energy emission from additional X-ray observations obtained with...
Early-type stars in the core of the young open cluster Westerlund 2 (2007)
Rauw, Grégor, Manfroid, Jean, Gosset, Eric, Naze, Yaël, Sana, H, De Becker, Michaël, ...
Aims. The properties of the early-type stars in the core of the Westerlund 2 cluster are examined in order to establish a link between the cluster and the very massive Wolf-Rayet binary WR 20a as...
Naze, Yaël, Rauw, Grégor, Pollock, AMT, Walborn, NR, Howarth, ID
We present the analysis of phase-resolved X-ray and optical observations of the peculiar hot star HD 191612 (Of ? p). This star is known to display line-profile variations that are recurrent with a...
NGC6231: X-ray Properties of the Early-Type Star Population (2007)
Sana, H, Naze, Yaël, Gosset, Eric, Rauw, Grégor, Sung, H, Vreux, J-M
Based on a deep XMM-Newton observation of the young open cluster NGC6231, we derive the main X-ray properties of its early-type star population. Among the 610 X-ray sources detected in the field, 42...
The first orbital solution for the massive colliding-wind binary HD 93162 ( WR 25) (2006)
Gamen, R, Gosset, Eric, Morrell, N, Niemela, V, Sana, H, Naze, Yaël, ...
Context. Since the discovery, with the EINSTEIN satellite, of strong X-ray emission associated with HD 93162 (equivalent to WR 25), this object has been predicted to be a colliding-wind binary...
An XMM-Newton view of the young open cluster NGC 6231 - II. The OB star population (2006)
Sana, H, Rauw, Grégor, Naze, Yaël, Gosset, Eric, Vreux, Jean-Marie
In this second paper of the series, we pursue the analysis of the 180-ks XMM-Newton campaign towards the young open cluster NGC 6231 and we focus on its rich OB star population. We present a...
The atypical emission-line star Hen 3-209 (2006)
Naze, Yaël, Rauw, Grégor, Hutsemekers, Damien, Gosset, Eric, Manfroid, Jean, Royer, P
We analyse observations, spanning 15 yr, dedicated to the extreme emission-line object Hen 3-209. Our photometric data indicate that the luminosity of the star undergoes marked variations with a...
High Resolution X-ray Spectroscopy of Early-Type Stars (2006)
Rauw, Grégor, Pollock, AMT, Naze, Yaël
Although X-ray emission from massive, early-type stars has been known for almost thirty years, it is only with the advent of the high-resolution spectrographs aboard Chandra and XMM-Newton that a...
New light on the peculiar star HD108 (2006)
Naze, Yaël, Barbieri, C, Segafredo, A, Rauw, Grégor, De Becker, Michaël
HD 108 is a peculiar massive star of type Of?p, which present recurrent line profile variations. Archival data confirm the very long (50-60 yr) period of this star. Recent data show that the minimum...
The Peculiar Of?p Stars HD 108 and HD 191612: The X-ray View (2006)
Naze, Yaël, Rauw, Grégor, Walborn, N R, Howarth, I D
Not Available
In our technological world, Science is everywhere and to participate to the public debates, citizens will need some basic scientific notions. Raising awareness of the public in Science is thus always...
Spectroscopy of Massive Stars (2006)
Although rare, massive stars, being the main sources of ionizing radiation, chemical enrichment and mechanical energy in the Galaxy, are the most important objects of the stellar population. This...
The peculiar Of?p stars HD 108 and HD 191612 (2005)
Naze, Yaël, Rauw, Grégor, Walborn, N R, Howarth, I D
The Of?p spectral category was introduced by Walborn in 1972 to describe peculiar stars which possess intense emission lines of C III 4647,4650,4651. Recently, two of them, HD 108 and HD 191612, were...
Stars in the eyes, birth of a vocation ? (2005)
It is generally difficult to interest people to sciences, especially physics. However, astronomy has a great power of fascination, and can thus be used to attract people into the scientific world....
Naze, Yaël, Antokhin, II, Sana, H, Gosset, Eric, Rauw, Grégor
We present the analysis of an extensive set of high-resolution spectroscopic observations of HD 93161, a visual binary with a separation of 2 arcsec. HD 93161 A is a spectroscopic binary, with both...
Rauw, Grégor, Crowther, PA, De Becker, Michaël, Gosset, Eric, Naze, Yaël, Sana, H, ...
We analyse the optical spectrum of the very massive binary system WR20a (WN6ha + WN6ha). The most prominent emission lines, Halpha and He II lambda4686, display strong phase-locked profile...
Gosset, Eric, Naze, Yaël, Rauw, Grégor, Vreux, Jean-Marie, Sana, H.
We present the results of an XMM-Newton observation of the field of the Wolf-Rayet star WR 40. Despite a nominal exposure of 20 ks and the high sensitivity of the satellite, the star itself is not...
A period and a prediction for the Of ? p spectrum alternator HD 191612 (2004)
Walborn, Nolan R., Howarth, Ian D., Rauw, Grégor, Lennon, Daniel J., Bond, Howard E., Negueruela, Ignacio, ...
The observational picture of the enigmatic O-type spectrum variable HD 191612 has been sharpened substantially. A symmetrical, low-amplitude light curve with a period near 540 days has recently been...
Naze, Yaël, Manfroid, Jean, Stevens, IR, Corcoran, MF, Flores, A
We present new XMM-Newton results on the field around the NGC 346 star cluster in the SMC. This continues and extends previously published work on Chandra observations of the same field. The two...
WR 20a: A massive cornerstone binary system comprising two extreme early-type stars (2004)
Rauw, Grégor, De Becker, Michaël, Naze, Yaël, Crowther, PA, Gosset, Eric, Sana, H, ...
We analyse spectroscopic observations of WR20a revealing that this star is a massive early-type binary system with a most probable orbital period of similar to3.675 days. Our spectra indicate that...
XMM-Newton observations of the giant H II region N 11 in the LMC (2004)
Naze, Yaël, Antokhin, II, Rauw, Grégor, Chu, YH, Gosset, Eric, Vreux, Jean-Marie
Using the sensitive XMM-Newton observatory, we have observed the giant H II region N11 in the LMC for similar to30 ks. We have detected several large areas of soft diffuse X-ray emission along with...
HD 108: The mystery deepens with XMM-Newton observations (2004)
Naze, Yaël, Rauw, Grégor, Vreux, Jean-Marie, De Becker, Michaël
In 2001, using a large spectroscopic dataset from an extensive monitoring campaign, we discovered that the peculiar Of star HD 108 displayed extreme line variations. This strange behaviour could be...
WR bubbles and HeII emission (2003)
Naze, Yaël, Rauw, Grégor, Manfroid, Jean, Chu, YH, Vreux, Jean-Marie
We present the very first high quality images of the He II lambda4686 emission in three high excitation nebulae of the Magellanic Clouds. A fourth high excitation nebula, situated around the WR star...
Naze, Yaël, Hartwell, JM, Stevens, IR, Manfroid, Jean, Marchenko, S, Corcoran, MF, ...
We present results from a Chandra observation of the NGC 346 cluster, which is the ionizing source of N66, the most luminous H II region and the largest star formation region in the SMC. In the first...
The wind of the B[e] supergiant Henize S22 viewed through a reflection nebula in DEM L106 (2003)
Chu, You-Hua, Chen, Chang-Hui Rosie, Danforth, Charles, Dunne, Bryan C., Gruendl, Robert A., Naze, Yaël, ...
Narrowband HST WFPC2 images reveal a bow-shock-like halo around the H II region N30B toward the B[e] supergiant Hen S22 located within the larger DEM L106 nebula in the Large Magellanic Cloud....
VLT observations of the highly ionized nebula around Brey2 (2003)
Naze, Yaël, Rauw, Grégor, Manfroid, Jean, Chu, YH, Vreux, Jean-Marie
We present the first high resolution He II lambda4686 images of the high excitation nebula around the WR star Brey2 in the LMC. This nebula presents a striking morphology: a small arc-like feature...
Gosset, Eric, Rauw, Grégor, Vreux, Jean-Marie, Naze, Yaël, Antokhin, Igor I, Sana, Hugues
A Massive Star Odyssey: From Main Sequence to Supernova, IAU S212
Structure and dynamics of candidate O star bubbles in N44 (2002)
Naze, Yaël, Chu, YH, Guerrero, MA, Oey, MS, Gruendl, RA, Smith, RC
Dynamical studies of superbubbles and Wolf-Rayet ring nebulae show discrepancies from the standard adiabatic model for windblown bubbles. We therefore study the physical properties and kinematics of...
Naze, Yaël, Hartwell, JM, Stevens, IR, Corcoran, MF, Chu, YH, Koenigsberger, G, ...
We present results from a Chandra observation of the NGC 346 cluster. This cluster contains numerous massive stars and is responsible for the ionization of N66, the most luminous H II region and the...
An XMM-Newton observation of the Lagoon Nebula and the very young open cluster NGC6530 (2002)
Rauw, Grégor, Naze, Yaël, Gosset, Eric, Stevens, IR, Blomme, Ronny, Corcoran, MF, ...
We report the results of an XMM-Newton observation of the Lagoon Nebula (M8). Our EPIC images of this region reveal a cluster of point sources, most of which have optical counterparts inside the very...
Line-Profile Variability in the Massive Binary System HD 149404 (2002)
Naze, Yaël, Carrier, Fabien, Rauw, Grégor
Not Available
Chandra/ACIS observation of NGC 346 (2001)
Naze, Yaël, Stevens, I R, Hartwell, J, XMEGA Group, Collaboration
The cluster NGC346 is the largest star formation region in the SMC. It contains a large fraction of the early-type O stars of this galaxy. In the outskirts of this cluster lies HD 5980, a unique...
Interstellar Bubbles in Two Young H II Regions (2001)
Naze, Yaël, Chu, You-Hua, Points, Sean D, Danforth, Charles W, Rosado, Margarita, Chen, C-H Rosie
Massive stars are expected to produce wind-blown bubbles in the interstellar medium; however, ring nebulae, suggesting the existence of bubbles, are rarely seen around main-sequence O stars. To...
What is the real nature of HD 108? (2001)
Naze, Yaël, Vreux, J-M, Rauw, Grégor
Since the beginning of the past century, the nature of HD 108 has been a subject of intense debate. One after another, astronomers explored its variability and attributed it either to binarity, or to...
The strange case of the massive binary HD 149404 (2001)
Rauw, Grégor, Naze, Yaël, Carrier, F, Burki, G, Gosset, Eric, Vreux, J-M
We report the analysis of an extensive set of high-resolution spectroscopic observations of the massive binary system HD 149404. We compare different techniques to measure the radial velocities of...
PSF modeling of the XMM flight mirror modules (1999)
Stockman, Yvan, Houbrechts, Yvette, Naze, Yaël, Rochus, Pierre, Tock, Jean P, Gondoin, Philippe
In the frame of XMM testing, all the mirror modules have been illuminated by a vertical EUV collimated beam a the Centre Spatial de Liege. A mirror module consists in 58 co- focal and co-axial Wolter...