Ultraviolet Observations of the Powering Source of the Supergiant Shell in IC 2574

2000 ◽  
Vol 120 (4) ◽  
pp. 1794-1800 ◽  
Author(s):  
Susan G. Stewart ◽  
Fabian Walter
Keyword(s):  
Ultraviolet Observations

scholarly journals ULTRAVIOLET OBSERVATIONS OF SUPERNOVAE

2007 ◽  
Author(s):  
Nino Panagia ◽  
Stefan Immler ◽  
Kurt Weiler
Keyword(s):  
Ultraviolet Observations

scholarly journals Ultraviolet Observations of Some Close Binary Systems by the Astronomical Netherlands Satellite-Ans

1976 ◽  
Vol 73 ◽  
pp. 213-223
Author(s):  
Chi-Chao Wu
Keyword(s):  
Binary Systems ◽  
Hot Spot ◽  
Close Binary ◽  
Spectral Energy ◽  
Dwarf Novae ◽  
Energy Distributions ◽  
Primary Star ◽  
Higher Temperature ◽  
Far Ultraviolet ◽  
Ultraviolet Observations

Observations of δ Pic, a β Lyr type of eclipsing binary and seven dwarf novae are reported. The ultraviolet light curves of δ Pic indicate the accumulation of matter at the triangular Lagrangian points L4 and L5, the presence of a hot spot and a higher temperature for the primary star. The implication is that the cooler secondary fills its Roche lobe and is transfering mass to the primary; mass loss to the circumstellar space and possibly to the system may also be appreciable. The temperatures of dwarf novae are derived by comparing their ultraviolet spectral energy distributions with those for normal stars of luminosity classes IV and V. Piecing together observations for different objects, the SSCyg systems have temperatures of 28 500 K, 10 000 K and 9500 K, respectively, when they are at minimum, immediately before outburst and at the beginning of rise to maximum. At maximum, the temperature is 22 500 K or 17 300 K depending on the interstellar reddening correction for AR And. Immediately before outburst, there is a large excess of flux in the far ultraviolet as indicated by the large value of the ratio of flux at 1550 Å to that at 1800 Å. The observations of Z Cam during standstill gives a temperature of 14 900 K. No excess of flux in the far ultraviolet was observed during the maximum of AR And and the standstill of Z Cam.

scholarly journals OPTICAL AND ULTRAVIOLET OBSERVATIONS OF THE VERY YOUNG TYPE IIP SN 2014cx IN NGC 337

2016 ◽  
Vol 832 (2) ◽  
pp. 139 ◽  
Author(s):  
Fang Huang ◽  
Xiaofeng Wang ◽  
Luca Zampieri ◽  
Maria Letizia Pumo ◽  
Iair Arcavi ◽  
...  
Keyword(s):  
Ultraviolet Observations

scholarly journals Ultraviolet Observations of Cataclysmic Variables

1987 ◽  
Vol 93 ◽  
pp. 205-205 ◽  
Author(s):  
F. Verbunt
Keyword(s):  
Orbital Period ◽  
Cataclysmic Variables ◽  
Type Systems ◽  
Terminal Velocity ◽  
Dwarf Novae ◽  
Preliminary Results ◽  
System Type ◽  
International Ultraviolet Explorer ◽  
Flux Level ◽  
Ultraviolet Observations

AbstractThe preliminary results of the analysis of more than 1000 spectra of cataclysmic variables in the archive of the International Ultraviolet Explorer were presented at the meeting. To characterize the slope of the spectra I use F = log(f1460Å/f2880Å). For most spectra F lies between 0.2 and 0.7. No correlation of F with orbital period, inclination, system type or (for dwarf novae) length of the interoutburst interval are found, apart from somewhat lower values of F for DQ Her type systems. Out of 16 dwarf novae for which spectra both at outburst maximum and minimum are available 11 show no large difference in F between maximum and minimum, and in 5 F declines with the flux level. Out of 6 dwarf novae 5 show very red spectra during the rise to maximum, and 1 shows slopes during rise similar to those during decline.In the ultraviolet resonance lines, due to a wind from the disc, no correlation is found between inclination and terminal velocity.

scholarly journals Discovery of an Extremely Short Duration Flare from Proxima Centauri Using Millimeter through Far-ultraviolet Observations

2021 ◽  
Vol 911 (2) ◽  
pp. L25
Author(s):  
Meredith A. MacGregor ◽  
Alycia J. Weinberger ◽  
R. O. Parke Loyd ◽  
Evgenya Shkolnik ◽  
Thomas Barclay ◽  
...  
Keyword(s):  
Short Duration ◽  
Far Ultraviolet ◽  
Ultraviolet Observations

scholarly journals X-ray and ultraviolet observations of the dwarf nova VW Hyi in quiescence

2003 ◽  
Vol 346 (4) ◽  
pp. 1231-1241 ◽  
Author(s):  
Dirk Pandel ◽  
France A. Córdova ◽  
Steve B. Howell
Keyword(s):  
X Ray ◽  
Dwarf Nova ◽  
Ultraviolet Observations

scholarly journals Abundances in Diffuse Interstellar Clouds

1980 ◽  
Vol 5 ◽  
pp. 293-300 ◽  
Author(s):  
M. Jura
Keyword(s):  
Interstellar Extinction ◽  
Future Research ◽  
Chemical Compositions ◽  
Interstellar Clouds ◽  
Dark Clouds ◽  
Neutral Gas ◽  
Self Gravity ◽  
Ultraviolet Observations ◽  
Diffuse Clouds ◽  
Intercloud Medium

Interstellar clouds are concentrations of cold (T ≲ 100 K) neutral gas (cf. Spitzer 1978) which are immersed within an intercloud medium. It is worthwhile to distinguish between diffuse clouds (roughly those with E[B-V] ≳ 0.5) and dark clouds (those with E[B-V] ≳ 0.5). This distinction is useful in the sense that diffuse clouds are relatively warm (T ∼ 100 K), they are composed mostly of atomic species except for hydrogen which can be appreciably molecular, and they are dynamically controlled by their interaction with the intercloud medium. Dark clouds are relatively cold (T ∼ 10 K), they contain a rich variety of molecules, and self-gravity is important in their evolution. Because the interstellar extinction is a rapid function of wavelength, most ultraviolet observations have been of diffuse clouds. The IUE satellite is sufficiently powerful that observations of some dark clouds are possible, and an important area of future research will be to delineate more quantitatively the similarities and differences between diffuse clouds and dark clouds.With ultraviolet observations, considerable progress has been made in understanding the physical characteristics of clouds including determinations of their densities, temperatures, chemical compositions and dynamics (cf. Spitzer and Jenkins 1976). Because particular progress has been made on understanding the abundances within diffuse clouds and because of the limitations of space, we restrict this review to a discussion of abundances within diffuse clouds. These abundance measurements provide a set of fundamental astrophysical data.

scholarly journals Horizontal supergranule-scale motions inferred from TRACE ultraviolet observations of the chromosphere

2010 ◽  
Vol 519 ◽  
pp. A58 ◽  
Author(s):  
H. Tian ◽  
H. E. Potts ◽  
E. Marsch ◽  
R. Attie ◽  
J.-S. He
Keyword(s):  
Ultraviolet Observations
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