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A study of the two northern open clusters NGC 1582 and NGC 1663
We present CCD UBV(I)C observations obtained in the field ofthe previously unstudied northern open clusters NGC 1582 and NGC 1663.For the former, we also provide high-resolution spectra of the brighteststars and complement our data with Two-Micron All-Sky-Survey (2MASS)near-infrared photometry and with astrometric data from the Tycho-2catalog. From the analysis of all these data, we argue that NGC 1582 isa very poor, quite large and heavily contaminated open cluster. It turnsout to have a reddening EB-V = 0.35 +/- 0.03, to be situated1100 +/- 100 pc from the Sun and to have an age of 300 +/- 100 Myr. Onthe other hand, we were not able to unambiguously clarify the nature ofNGC 1663. By assuming it is a real cluster and from the analysis of itsphotometric diagrams, we found a color excess value EB-V =0.20, an intermediate age value ( ~ 2000 Myr) and a distance of about700 pc. The distribution of the stars in the region however suggests weare probably facing an open cluster remnant. As an additional result, weobtained aperture photometry of three previously unclassified galaxiesplaced in the field of NGC 1663 and performed a preliminarymorphological classification of them.Based on observations carried out at Mt Ekar, Asiago, Italy.Data are only available in electronic form at the CDS via anonymous ftpto cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/407/527
| 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.
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