EDP Sciences
Free access
Volume 377, Number 3, October III 2001
Page(s) 994 - 998
Section Stellar atmospheres
DOI http://dx.doi.org/10.1051/0004-6361:20011164

A&A 377, 994-998 (2001)
DOI: 10.1051/0004-6361:20011164

Detection of the unusual 3.5 $\mu$m feature in the Herbig Be star MWC 297

H. Terada1, M. Imanishi2, M. Goto1 and T. Maihara3

1  Subaru Telescope, National Astronomical Observatory of Japan, Hilo, Hawaii 96720, USA
2  National Astronomical Observatory, Mitaka, Tokyo, 181-8588, Japan
3  Department of Astronomy, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan

(Received 2 September 1999 / Accepted 20 August 2001 )

We present spectroscopic observations of MWC 297 with medium spectral resolution in the 2.1-4.1 $\mu$m region, that show the unusual emission band at 3.53 $\mu$m as well as gaseous emission lines of the Brackett, Pfund and Humphrey series of hydrogen. A unique aspect of the measured 3.53 $\mu$m emission band is the fact that, within our detection limit, it is not accompanied by the 3.3 and 3.4 $\mu$m emission band. We suggest that the 3.53 $\mu$m feature could be emitted by highly dehydrogenized carbonaceous dust particles that were processed under the influence of the strong radiation field of the central star.

Key words: infrared: stars -- ISM dust -- stars: individual: MWC 297 -- stars: circumstellar matter

Offprint request: H. Terada, terada@subaru.naoj.org

SIMBAD Objects

© ESO 2001