Ultraviolet photometry from the orbiting astronomical observatory. V. The helium-weak stars.
1972; IOP Publishing; Volume: 178; Linguagem: Inglês
10.1086/151779
ISSN1538-4357
AutoresP. L. Bernacca, Michael Molnar,
Tópico(s)Photocathodes and Microchannel Plates
Resumoview Abstract Citations (16) References (22) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Ultraviolet photometry from the Orbiting Astronomical Observatory. V. The helium-weak stars. Bernacca, P. L. ; Molnar, M. R. Abstract Ultraviolet filter photometry with the Wisconsin Experiment Package aboard OAO-2 has been carried out for the helium-weak stars 3 Cen A, 3 Sco, RD 144334, RD 21699, RD 144844, a Scl, RR 8535, RR 8770, and RD 144661. The flux distribution is compared with that of B3 to B8 main-sequence and giant stars in terms of color-color diagrams. After taking into consideration line blocking shortward of 2800 A due to lines of P ii, Ga ii, Si ii, Si iii, Ti ii, and Sr ii, we find that most of the helium-weak stars have normal fluxes in good agreement with their ground-based colors. Rowever, it is difficult to consider RR 8535, RR 8770, and RD 144661 as having normal flux distributions and they may be brighter than normal at 3320 A. The star, a Scl, is a photometric variable. It is suggested that variations in the strengths of lines of Ti ii, Cr ii, and Sr ii around 2400 A are responsible for this phenomenon, causing a redistribution of flux between the far-ultraviolet and visual regions. The flux distribution indicates an effective temperature about 1500 K higher than previously determined. Publication: The Astrophysical Journal Pub Date: November 1972 DOI: 10.1086/151779 Bibcode: 1972ApJ...178..189B full text sources ADS | data products SIMBAD (32) Related Materials (37) Part 1: 1970ApJ...161..377C Part 2: 1972ApJ...171..293B Part 3: 1972ApJ...172..755W Part 4: 1972ApJ...178..727D Part 6: 1972ApJ...178..495D Part 7: 1973ApJ...179..527M Part 8: 1973ApJ...185..577L Part 9: 1973ApJ...185..921E Part 10: 1974ApJ...189..303G Part 11: 1974ApJ...187..521D Part 12: 1973ApJ...186..939H Part 13: 1974ApJ...187..197S Part 14: 1974ApJ...187..243J Part 15: 1974ApJ...190..319L Part 16: 1974ApJ...191..659S Part 17: 1975ApJ...195..121D Part 18: 1975ApJ...197..379E Part 19: 1975ApJ...199...92S Part 20: 1976ApJ...203..410B Part 21: 1976Ap&SS..41..121K Part 22: 1976ApJ...206..167P Part 23: 1976ApJ...208..135L Part 24: 1976ApJ...208...64L Part 25: 1979ApJ...228...95C Part 26: 1977ApJ...211..207H Part 27: 1978ApJ...219..947L Part 28: 1978ApJ...222..909W Part 29: 1978ApJ...220..582E Part 30: 1979ApJS...39..195C Part 31: 1979ApJ...229..994G Part 32: 1980ApJS...43..501C Part 33: 1979ApJ...228..419W Part 34: 1980ApJ...236..798W Part 35: 1980ApJS...42..283M Part 36: 1984ApJ...281..774C Part 37: 1982ApJ...256....1C Part 38: 1982AJ.....87..849D
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