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The Henry Draper Extension Charts: A catalogue of accurate positions, proper motions, magnitudes and spectral types of 86933 stars
The Henry Draper Extension Charts (HDEC), published in the form offinding charts, provide spectral classification for some 87000 starsmostly between 10th and 11th magnitude. This data, being highlyvaluable, as yet was practically unusable for modern computer-basedastronomy. An earlier pilot project (Roeser et al. 1991) demonstrated apossibility to convert this into a star catalogue, using measurements ofcartesian coordinates of stars on the charts and positions of theAstrographic Catalogue (AC) for subsequent identification. We presenthere a final HDEC catalogue comprising accurate positions, propermotions, magnitudes and spectral classes for 86933 stars of the HenryDraper Extension Charts.
| Photoelectric observations of classical cepheids.
Not Available
| A search for radial velocity variations in the blue stragglers of NGC 7789
Image-tube spectra have been obtained for seven bright, blue stragglersin NGC 7789. Statistical tests applied to the data indicate that thesestars do not have radial velocity variations greater than the detectionlimit of approximately 12 km/s. Corrections have been made for possiblesemiamplitudes smaller than this limit. The corrected possible binaryfrequency is about the same or less than the frequency observed in openclusters for stars of these early spectral types. The conclusion isthat, although some stragglers may be binaries, duplicity, or at leastclose duplicity, is unlikely to be a necessary condition for theexistence of all blue stragglers.
| Spectral Classification in Some Open Clusters.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1961ApJ...134..612S&db_key=AST
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Membre dels grups següents:
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Dades d'Observació i Astrometria
| Constel·lació: | Vulpecula |
| Ascensió Recta: | 19h30m14.71s |
| Declinació: | +20°19'52.7" |
| Magnitud Aparent: | 9.059 |
| Moviment propi RA: | 14.1 |
| Moviment propi Dec: | -0.8 |
| B-T magnitude: | 10.437 |
| V-T magnitude: | 9.173 |
Catàlegs i designacions:
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