scholarly journals Notes on Van der Meer scan for absolute luminosity measurement

2011 ◽  
Vol 654 (1) ◽  
pp. 634-638 ◽  
Author(s):  
Vladislav Balagura
Keyword(s):  
Absolute Luminosity

scholarly journals 12. The measurement of the distance of the radio sources

1957 ◽  
Vol 4 ◽  
pp. 71-79 ◽  
Author(s):  
R. D. Davies ◽  
D. R. W. Williams
Keyword(s):  
Radio Emission ◽  
Surface Area ◽  
Radio Astronomy ◽  
Angular Size ◽  
Radio Sources ◽  
Absolute Luminosity

In radio astronomy it is becoming increasingly important to know the distance of the radio sources. An identification with astronomical objects observed optically is then more readily obtained and this in turn may allow further investigation of the mechanism of radio emission. A measurement of the distance of sources will also resolve the problem of their distribution in space, showing which are galactic and which are extra-galactic. Furthermore the surface area and absolute luminosity can be estimated from a knowledge of the distance and angular size of a source.

scholarly journals High-Speed Photometry of Cluster Flare Stars

1975 ◽  
Vol 67 ◽  
pp. 69-73
Author(s):  
M. Rodonò
Keyword(s):  
High Speed ◽  
Activity Level ◽  
Flare Star ◽  
Solar Neighbourhood ◽  
High Occurrence ◽  
High Speed Photometry ◽  
Flare Stars ◽  
Photoelectric Observations ◽  
Absolute Luminosity

Recent photoelectric observations made at Catania Observatory show a high occurrence of short-lived faint flares on the Hyades member II Tau (H II 2411). Its activity level turns out to be higher than for UV Cet-type stars of equal absolute luminosity.II Tau could represent a transition prototype between UV Cet-type flare star in the solar neighbourhood and cluster ones.The importance of coordinated photoelectric patrol of properly selected flare stars in clusters of different age is emphasized.

scholarly journals Luminosity Classification of Be Stars by Balmer Line Narrow Band Photometry

1982 ◽  
Vol 98 ◽  
pp. 37-40
Author(s):  
Wolfgang Zeuge
Keyword(s):  
Narrow Band ◽  
Balmer Line ◽  
Be Stars ◽  
The Absolute ◽  
Absolute Luminosity

The absolute luminosity of most Be stars can be determined by using Balmer line narrow band photometry with an accuracy of about 0.4 mag. The few cases in which this method fails can be detected.

scholarly journals Observational properties of galaxies in small systems

2000 ◽  
Vol 174 ◽  
pp. 86-89
Author(s):  
M. Jõeveer
Keyword(s):  
Small Systems ◽  
The Mean ◽  
Absolute Luminosity

AbstractThe mean absolute luminosities and diameters of galaxies in double and triple configurations are compared with the same characteristics for single galaxies. Members of optical pairs and triplets are used as the sample of single galaxies. The mean luminosities of galaxies in physical pairs and triplets are found to be the same as for single galaxies. At the same absolute luminosity, single galaxies have larger diameters compared to galaxies in pairs and triplets.

On precision measurement of the LHC absolute luminosity

2014 ◽  
Author(s):  
M. W. Krasny ◽  
J. Chwastowski ◽  
A. Cyz ◽  
K. Słowikowski
Keyword(s):  
Precision Measurement ◽  
Absolute Luminosity

scholarly journals Measurement of the absolute luminosity with the ALEPH detector

1992 ◽  
Vol 53 (3) ◽  
pp. 375-390 ◽  
Author(s):  
◽  
D. Decamp ◽  
B. Deschizeaux ◽  
C. Goy ◽  
J. -P. Lees ◽  
...  
Keyword(s):  
Aleph Detector ◽  
The Absolute ◽  
Absolute Luminosity

scholarly journals Concerning the Primordial Abundance of Helium in Quasi-Stellar Sources

1972 ◽  
Vol 44 ◽  
pp. 474-477
Author(s):  
Joseph Silk
Keyword(s):  
Galaxy Formation ◽  
Temperature Fluctuations ◽  
Helium Content ◽  
Primordial Abundance ◽  
Primordial Helium ◽  
Stellar Sources ◽  
Absolute Luminosity

Primordial temperature fluctuations, which appear to be necessary in order to explain aspects of galaxy formation, can lead to observable effects in some objects. In QSS and other compact systems a correlation of absolute luminosity with primordial helium content is predicted.

scholarly journals Ultraviolet Light Curves Of U Geminorum and VW Hydri

1982 ◽  
Vol 69 ◽  
pp. 191-197
Author(s):  
Chi-Chao Wu ◽  
R.J. Panek ◽  
A.V. Holm ◽  
F.H. Schiffer
Keyword(s):  
Ultraviolet Light ◽  
Accretion Disks ◽  
Flux Distribution ◽  
Hot Spot ◽  
Light Curves ◽  
Bright Spot ◽  
Uv Spectrum ◽  
Primary Star ◽  
Spot Temperature ◽  
Absolute Luminosity

AbstractUltraviolet light curves have been obtained for the quiescent dwarf novae U Gem and VW Hyi. The amplitude of the hump associated with the accretion hot spot is much smaller in the UV than in the visible. This implies that the bright spot temperature is roughly 12000 K if it is optically thick. A hotter spot would have to be optically thin in the near UV. The flux distribution of U Gem in quiescence cannot be fitted by model spectra of steady state, viscous accretion disks. The absolute luminosity, the flux distribution, and the far UV spectrum suggest that the primary star is visible in the far UV. The optical-UV flux distribution of VW Hyi could be matched roughly by our model accretion disks, but the fitting is poorly constrained due to the uncertainty in its distance.

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