A dataset provided by the European Space Agency

Name OBDWARF
Title INFRARED SPECTROSCOPY OF NORMAL O AND B STARS A SEARCH FOR LOW-DENSITY CIRCUMSTELLAR GAS
URL

http://nida.esac.esa.int/nida-sl-tap/data?RETRIEVAL_TYPE=OBSERVATION&PRODUCT_LEVEL=ALL&obsno=393006170
DOI https://doi.org/10.5270/esa-t5o1ksq
Author WATERS, LAURENS B
Description we propose to study the infrared spectra of normal ob main sequence stars in order to investigate the structure of the outer layers of the photosphere and to determine the possible presence of a weak stellar wind. ground-based observations of normal ob dwarfs demonstrate that ir hydrogen lines (br-alpha) can be strongly in emission while the h-alpha line is in absorption (waters et al. 1993; murdoch et al. 1994). model calculations of the photospheric and wind emission of ob dwarfs indicate that, for very low mass loss rates, the hydrogen recombination lines in the 4 to 40 micron wavelength range are still expected to show emission. this is due to the fact that the ir continuum of hot stars drops very rapidly with increasing wavelength, whereas the strength of the hi recombination lines decreases more slowly. this results in easily detectable emission lines in the 10-40 micron window. however in a recent paper by murdoch el al. (1994) it is suggested that the ir emission may be due to a non-lte effect in the outermost photospheric layers of hot stars. both models predict different line strength ratios for the ir emission lines. measurement of the strength of several hydrogen lines in the sws wavelength range will allow us to distinguish between both models. the study of the outer layers of the atmospheres of (hot) stars and of weak stellar winds can only be done with iso.
Instrument PHT40 , SWS02
Temporal Coverage 1996-03-07T04:11:22Z/1997-08-07T06:59:29Z
Version 1.0
Mission Description The Infrared Space Observatory (ISO) was the worlds first true orbiting infrared observatory. Equipped with four highly-sophisticated and versatile scientific instruments, it was launched by Ariane in November 1995 and provided astronomers world-wide with a facility of unprecedented sensitivity and capabilities for a detailed exploration of the Universe at infrared wavelengths.
Creator Contact https://support.cosmos.esa.int/iso/
Date Published 1999-05-29T00:00:00Z
Last Update 2026-07-09
Keywords Infrared Space Observatory data, ESA ISO mission dataset, ISO infrared observations, mid-infrared astronomy data, far-infrared spectroscopy dataset, ISOCAM imaging data, ISOPHOT photometry data, SWS short wavelength spectrometer data, LWS long wavelength spectrometer data, infrared spectral line observations, infrared imaging survey data, dust emission infrared observations, star formation infrared dataset, interstellar medium spectroscopy data, polycyclic aromatic hydrocarbons PAH features data, active galactic nuclei infrared observations, circumstellar envelope infrared data, planetary nebula infrared spectroscopy, extragalactic infrared survey data, calibrated ISO data products, FITS files infrared astronomy, spectral energy distribution infrared data, continuum photometry dataset, infrared spectral cubes, flux-calibrated infrared maps, ESA ISO Data Archive, legacy infrared space mission dataset
Publisher And Registrant European Space Agency
Credit Guidelines European Space Agency, WATERS et al., 1999, 'INFRARED SPECTROSCOPY OF NORMAL O AND B STARS A SEARCH FOR LOW-DENSITY CIRCUMSTELLAR GAS', 1.0, European Space Agency, https://doi.org/10.5270/esa-t5o1ksq
Rights Data hosted in the ESA Space Science Archives are distributed under the CC BY-NC 3.0 IGO license.