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X-ray and UV observations of two radio-bright quasars.
Elvis, M.; Fabbiano, G.
The two quasars PKS 10004 + 13 (4C 13.41, V about equal to 15.2, z = 0.140) and PKS 0637 - 75 (V = 15.75, z = 0.651) were observed in December 1980 with IUE. Both were detected in the short-wavelength region. The present X-ray upper limit for PKS 1004 + 13 gives the lowest L-x/L-opt measured in quasars. PKS 0637 - 75 was observed nearly simultaneo…
Multigrequency spectral behavior of the BL Lacertae objects OI 90.4 and 3C 66A.
Bruhweiler, F. C.; Miller, H. R.; Worrall, D. M. +4 more
Single-epoch multifrequency data for the BL Lac objects OI 90.4 and 3C 66A, spanning radio through ultraviolet wavelengths, are presented, as well as other measurements relevant to intensity and spectral-shape variability. Both BL Lac objects exhibit spectral curvature in the infrared-to-ultraviolet region, a properity that is inferred to be usual…
Ultraviolet spectra of planetary nebulae - X. Physical conditions in the compact planetary nebula SW ST 1.
Cohen, M.; Flower, D. R.; Goharji, A.
The authors analyse photoelectric visual and ultraviolet observations of the compact planetary nebula Sw St 1. The electron density, determined from the C III λλ1907/1909 line ratio, is Ne = (1.1±0.1)×105cm-3, consistent with the high emission measure and high critical frequency determined from observations of the …
Spectrophotometry of southern Herbig-Haro and related objects.
Krautter, J.; Eichendorf, W.; Reipurth, B.
In this note, spectrophotometry is presented for four Herbig-Haro or Herbig-Haro-like objects. HH 55 is observed for the first time, and has a typical HH spectrum but with weak forbidden N II lines and indication of a weak continuum. M 16 HH 1 shows an extreme weakness of the forbidden OI lines which sets it apart from all known HH objects. Th 28 …
On the dispersion in brightness of far-ultraviolet emission lines of cool giant stars.
Simon, T.
Low-resolution spectra have been obtained with the short-wavelength camera of IUE for late-type giant stars of spectral type F5 III-G8 III. These stars are believed to be in their first crossing of the H-R diagram, as inferred from their location along the blue edge of the Hertzsprung gap or their high abundance of lithium. From the earliest spect…
Rotational modulation of the chromospheric activity in KHI 1 Orionis (GO V).
Simon, T.; Boesgaard, A. M.
The solar type star χ1 Ori is thought to have an age of 6×108yr and an apparent rotation period of 5d.1. These characteristics make it well suited for a rotational modulation study of its strong ultraviolet emission lines. The authors have made IUE observations at four different phases during each of three separate…
Multifrequency observations of the BL Lacertae objects OQ 530 and ON 325.
Bruhweiler, F. C.; Miller, H. R.; Sitko, M. L. +10 more
Spectral measurements of the two BL Lac objects OQ 530 and ON 325 are presented. The measurements were taken at frequencies ranging from radio to ultraviolet. Both sources show spectral curvature between the infrared and ultraviolet frequencies. The intensity and spectral shape of OQ 530 vary, but the spectral shape of ON 325 appears to remain con…
IUE low-dispersion spectra flux catalogue. Part 1 Normal stars (magnetic tape).
Heck, A.; Egret, D.; Jaschek, M. +1 more
A magnetic tape catalog of the fluxes (2A-step) of 229 selected low-dispersion stellar spectra prepared by the Centre de Calcul de Strasbourg-Cronenbourg is presented in the form of a set of tables. The catalog uses the general MK frame and centers on stars exhibiting normal behavior in the ultraviolet. All the stars included in the catalog are li…
IUE observations of UV bright stars in the globular clusters M15 and omega Cen.
Cacciari, C.; Fusi Pecci, F.; Caloi, V. +1 more
IUE spectra in the low dispersion mode are reported for three UV-bright stars. Two of them (stars K 559 and K 996) are members of the very metal poor cluster M15 and one (star ROA 5701) is a member of the populous cluster ω Cen. The authors find E(B-V) = 0.11 as a lower limit for the reddening of ω Cen whereas the reddening of M15 should not be la…
The 1982 eclipse of 31 Cygni.
Kondo, Y.; Stencel, R. E.; Chapman, R. D. +4 more
UBV photometry and optical-UV spectroscopy of the primary eclipse of the long period ζ Aurigae-like system 31 Cygni are reported. The precise timings made possible by the photometry imply that the spectral features could be due to an accretion shock associated with a hot star embedded in an extended chromosphere surrounding the red supergiant. The…