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The star-formation history of GR8 with HST imagery.

Dufour, R. J.; Wyatt, R. J.

The authors report the results of a deep imaging study of the nearby irregular galaxy GR8 using the Wide-Field Camera on the Hubble Space Telescope. These data enable them to perform photometry on stars as faint as R ≡ 24.5 with spatial resolution superior to ground-based observations. Color-magnitude diagrams in the "BVR" filters are presented an…

Structure, motion, and composition of the Orion Nebula.

O'Dell, C. R.

The author reviews the large scale structure of the Orion Nebula, incorporating recent results from 21 cm absorption studies, optical emission line investigations, and Hubble Space Telescope imaging. The ionization structure at the brightest ionization front is clearly defined and demonstrates a well organized flow away from the front. The ionized…

Comparisons of IUE & HST ultraviolet spectra of extragalactic H II regions.

Terlevich, E.; Terlevich, R.; Garnett, D. R. +5 more

The authors compare recently obtained HST FOS and IUE SWP ultraviolet spectra of two extragalactic H II regions: SBS 0335-052 and 30 Doradus in the LMC. They also present IUE SWP NEWSIPS processed spectra of I Zw 18, which show significant improvements in the data quality, suggesting that reprocessed IUE archival spectra will offer enhanced scienc…

HST FOC/48 UV imagery of GR8.

Dufour, R. J.; Wyatt, R. J.; Patterson, B.

Imagery observations of GR8 were made in July 1991 with the Hubble Space Telescope. The Wide Field Camera imaged the entire galaxy at 5500 Å (F555W), 4390 Å (F439W), and 3360 Å (F336W); and two smaller fields around the H II regions HL5 and HL19 were imaged at 1400 Å (F150W) with the Faint Object Camera. B and V magnitudes for these stars are from…

Calibration of HST narrow band filters using the Orion Nebula.

Hu, Xihai

HST images in three emission line filters: Hα, [O III] and [N II] have been calibrated. The CCD sensitivity was determined by comparing regions within HST frames with the corresponding surface brightness determined from ground based Orion Nebula observations. Corrections for continuum within each filter were made. It was necessary to correct the […

HST imaging of the wind-blown lobe NGC 6165.

Hester, J.; Scowen, P.; Code, A. +1 more

WFC observations of the lobe NGC 6165 have resolved clumps that are being photoevaporated by the intense UV radiation from HD 148937, in addition to the erosive effects of the strong stellar wind. The central object is a massive superluminous young star that is thought to be undergoing mass loss as it descends onto the main sequence. Analysis of s…