Search Publications
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…
Rotational velocities of later B type and A type stars as determined from ultraviolet versus visual line profiles.
Sonneborn, G.; Carpenter, K. G.; Slettebak, A.
Theoretical line profiles of the Si III 1299 and Fe II 2756 lines are computed for rotating B5-A7 model stars, and compared with observed profiles from IUE spectra to derive rotational velocities. Real differences in widths for ultraviolet as compared with visual line profiles exist in the sample of B type stars (but not for the A type rapidly rot…
Similar photospheres, different mantles : a study of four O stars.
Underhill, A. B.
The present investigation is concerned with a comparison of the spectra of four O stars (10 Lac, S Mon, HD 46223, and Zeta Pup) which have similar effective temperatures, taking into account an attempt to find the reason for differences regarding the spectral type of the stars. The photospheres of the stars are examined, taking into account the ef…
A study of the expanding envelope around the pole-on Be star HR 5223.
Dachs, J.; Hanuschik, R.
A spectroscopic/photometric survey was performed on the Be star HR 5223 to characterize physical conditions in high- and low-velocity regions and the source regions of observed stellar winds and Balmer line-emitting envelopes of Be stars. Data were gathered from 1978-82 at La Silla and with the IUE spacecraft, and comprised UBV, IR, and UV photome…
IUE observations of high velocity interstellar gas toward stars within the OB association CYG OB1.
Pettini, M.; Phillips, A. P.; Welsh, B. Y.
High-velocity interstellar gas has been detected in IUE spectra of the stars HD 192639, 193514 and 193443 which are members of the OB association Cyg OB1. In all cases where blending between different absorption components is not severe, the authors have derived ion column densities appropriate to the high-velocity gas by fitting theoretical profi…
Gas in cosmic voids.
Brosch, N.; Gondhalekar, P. M.
Absorption lines at the redshifts of cosmic voids in Perseus-Pisces and Bootes have been detected in the ultraviolet spectra of background quasars. The detection of metal lines suggests chemical enrichment of gas in the voids in support of explosion dominated model of formation of galaxies (Ostriker and Cowie, 1981).