No high-mass protostars in the silhouette young stellar object M17-SO1.
The birth of very massive stars is not well understood, in contrast to the formation process of low-mass stars like our Sun. It is not even clear that massive stars can form as single entities; rather, they might form through the mergers of smaller ones born in tight groups. The recent claim of the discovery of a massive protostar in M17 (a nearby giant ionized region) forming through the same mechanism as low-mass stars has therefore generated considerable interest. Here we show that this protostar has an intermediate mass of only 2.5 to 8 solar masses (M(o), contrary to the earlier claim of 20M(o) (ref. 8). The surrounding circumstellar envelope contains only 0.09M(o) and a much more extended local molecular cloud has 4-9M(o).
Sako
Shigeyuki
S
Department of Astronomy, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan. sako@ioa.s.u-tokyo.ac.jp
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Takuya
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Kataza
Hirokazu
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Miyata
Takashi
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Okamoto
Yoshiko K
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Mitsuhiko
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Fujiyoshi
Takuya
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Terada
Hiroshi
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Kamazaki
Takeshi
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Jiang
Zhibo
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Tomoyuki
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Onaka
Takashi
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