TY  - JOUR
A1  - Oskinova, Lida
A1  - Steinke, M.
A1  - Hamann, Wolf-Rainer
A1  - Sander, A.
A1  - Todt, Helge Tobias
A1  - Liermann, Adriane
T1  - One of the most massive stars in the Galaxy may have formed in isolation
JF  - Monthly notices of the Royal Astronomical Society
N2  - Very massive stars, 100 times heavier than the sun, are rare. It is not yet known whether such stars can form in isolation or only in star clusters. The answer to this question is of fundamental importance. The central region of our Galaxy is ideal for investigating very massive stars and clusters located in the same environment. We used archival infrared images to investigate the surroundings of apparently isolated massive stars presently known in the Galactic Centre (GC). We find that two such isolated massive stars display bow shocks and hence may be 'runaways' from their birthplace. Thus, some isolated massive stars in the GC region might have been born in star clusters known in this region. However, no bow shock is detected around the isolated star WR 102ka (Peony nebula star), which is one of the most massive and luminous stars in the Galaxy. This star is located at the centre of an associated circumstellar nebula. To study whether a star cluster may be 'hidden' in the surroundings of WR 102ka, to obtain new and better spectra of this star, and to measure its radial velocity, we obtained observations with the integral-field spectrograph SINFONI at the ESO's Very Large Telescope. Our observations confirm that WR 102ka is one of the most massive stars in the Galaxy and reveal that this star is not associated with a star cluster. We suggest that WR 102ka has been born in relative isolation, outside of any massive star cluster.
KW  - stars: individual: WR 102ka
KW  - Galaxy: centre
KW  - infrared: stars
Y1  - 2013
U6  - https://doi.org/10.1093/mnras/stt1817
SN  - 0035-8711
SN  - 1365-2966
VL  - 436
IS  - 4
SP  - 3357
EP  - 3365
PB  - Oxford Univ. Press
CY  - Oxford
ER  -