[Previous] | [Session 60] | [Next]
A. Danks (Emergent-IT and GSFC), G. Vieira (SAIC and GSFC), C. Grady (NOAO and GSFC), B. Woodgate (NASA's GSFC), A. Brown, G. Harper, E. Wilkinson (CASA, U. Colorado), C. Herczeg (JILA, U. Colorado and NIST), M. Sitko, A. Bauer (U. Cincinnati), J. Biggs (Perth Observatory, Australia)
We present HST/STIS white light coronagraphic imaging, STIS FUV low dispersion spectroscopy and FUSE moderate resolution spectroscopy supplemented by optical photometry of the nearby Herbig Ae star HD 104237. The coronagraphic data reveal a nearby star, hereafter termed HD 104237B, offset 1.4" (162 AU) from the Ae star as well as three additional bright stars more than 10" from HD 104237. All four nearby stars have magnitudes and colors, inferred from the shape of the PSF wings, characteristic of M8-M9 T Tauri stars. One of the companions varied significantly in the course of the first STIS coronagraphic imaging suite, consistent with flaring. The proximity of these stars indicate that the Herbig Ae star, hereafter termed HD 104237A, is located in a small T association. The proximity of the nearest companion to HD 104237 is consistent with the anomalously bright x-ray emission from HD 104237 originating at least partially on the companion, as originally suggested by Skinner & Yamauchi (1996). No circumstellar disk is visible in the STIS images, implying an outer disk radius below 57 AU, as expected from tidal truncation of HD 104237A disk by HD 104237B.
STIS low resolution long slit spectra covering 1150-1700 A were obtained with the 52x0.2" slit in the same orbits as the coronagraphic images. Both spectra resolve the wind in Lyman alpha, with an outer radius of at least 1.3" (150 AU) at PA=339 degrees. We also detect molecular hydrogen emission beyond the Ly alpha emission in both spectra at PA=319 and 339 degrees. At PA=339 degrees, the molecular hydrogen emission extends from 1.4 to 2.0" (160-230 AU). The FUSE, HST/GHRS and STIS spectra of HD104237 show a wide range of chromospheric and transition region emission lines. All except the hottest lines, i.e. N V and O VI, show the presence of a high velocity outflow with a maximum speed of ~ -300 km s{-1}. The O VI 1032 Å\ profile shows strong H2 molecular absorptions that lead to fluorecent FUV H2 emissions.
This study is part of the STIS Guaranteed Time Observation program, which is supported NASA GTO funding to the STIS Science Team in response to NASA A/O OSSA -4-84 through the HST Project at GSFC. CAG is supported through interagency transfer of funds to NOAO. A. Brown, GH, and E.W. are supported through LTSA grants NAG5-3226 and NAG5-4808. MS and A. Bauer are supported through the Ohio Space Grant program.