Spectral classification and UBV photometry of bright visual double stars

1977 ◽  
Vol 82 ◽  
pp. 431 ◽  
Author(s):  
T. E. Lutz ◽  
J. H. Lutz
Keyword(s):  
Spectral Classification ◽  
Double Stars ◽  
Visual Double Stars ◽  
Ubv Photometry

scholarly journals UBV CCD Photometry of “Close” Visual Double Stars

1992 ◽  
Vol 135 ◽  
pp. 362-364
Author(s):  
E. Van Dessel ◽  
D. Sinachopoulos ◽  
P. Prado
Keyword(s):  
Ccd Cameras ◽  
Ccd Photometry ◽  
Astrophysical Interest ◽  
Double Stars ◽  
Visual Double Stars ◽  
Ubv Photometry ◽  
Visual Binaries

AbstractWe use the CCD cameras of the 61-cm UTSO and the 90-cm Dutch telescopes of the Las Campanas and European Southern Observatories respectively in order to perform UBV photometry of visual double stars.Our sample contains southern visual binaries with A–type (470 pairs) and G–type primaries (170 pairs), which have angular separations mainly between 1″.5 and 5″. The double stars of our sample have been selected from the WDS according to their astrophysical interest and the technological limits of contemporary CCDs.

scholarly journals The European Network of Laboratories: Visual Double Stars

1992 ◽  
Vol 135 ◽  
pp. 454-456 ◽  
Author(s):  
E. Oblak ◽  
A.N. Argue ◽  
P. Brosche ◽  
J. Cuypers ◽  
J. Dommanget ◽  
...  
Keyword(s):  
Stellar Evolution ◽  
Photometric Data ◽  
Selection Effects ◽  
Spectral Classification ◽  
European Network ◽  
Double Stars ◽  
Visual Double Stars ◽  
Ccd Detectors ◽  
Colour Indices ◽  
Space Observations

The study of double stars has since long been recognized as a basic key to the understanding of star formation and stellar evolution. Moreover, close visual double stars have always been systematically neglected in photometric observational programmes although they contain an important part of physically associated systems. It is then timely to organize major observational programmes of these objects for a number of good reasons:1.The frequency of double stars is continuously reviewed and the rate of their detection is steadily increasing — both from ground–based and space observations — in such a way that they no longer can be discarded in any models of galactic structure;2.Space observations (HIPPARCOS, HST) significantly improve the quality and the importance of stellar samples and permit to better take into account some of the selection effects;3.The high–quality astrometric (and also photometric) data that will be provided for such systems by the space observations should be matched with accurate and homogeneous complementary astrophysical information such as colour indices and spectral classification. Such information for close visual double stars is unfortunately almost non-existent but are now being more easily accessible with the use of CCD detectors.

Spectroscopic Observations of Visual Double Stars

1965 ◽  
Vol 5 ◽  
pp. 109-111
Author(s):  
Frederick R. West
Keyword(s):  
Radial Velocity ◽  
High Dispersion ◽  
Velocity Difference ◽  
Spectrograph Slit ◽  
Spectroscopic Observations ◽  
Double Stars ◽  
Visual Double Stars ◽  
Relative Orbit ◽  
Two Component ◽  
Star Images

There are certain visual double stars which, when close to a node of their relative orbit, should have enough radial velocity difference (10-20 km/s) that the spectra of the two component stars will appear resolved on high-dispersion spectrograms (5 Å/mm or less) obtainable by use of modern coudé and solar spectrographs on bright stars. Both star images are then recorded simultaneously on the spectrograph slit, so that two stellar components will appear on each spectrogram.

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