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Long-term photometry of the symbiotic nova HM Sge
The long-term photometry of the symbiotic nova HM Sge obtained from 1976to 2003 is presented including new UBV photoelectric and UBVRI CCD datagathered in 1998-2003. The archive photographic plates were used toestimate the brightness of the object after the outburst in 1975. Thesedata together with post-outburst visual observations from internationaldatabases are discussed. The outburst of the nova, with a maximum inAugust 1975, was followed by two minima of brightness which lasted750 days and 2100 days, respectively. The descending branch ofthe minimum I was detected only in photographic data, the ascendingbranch was also detected in UBV bands. The minimum II was visible onlyin the U band. The minima were probably caused by the eclipses of thehot component (white dwarf surrounded by an accretion disk) and the hotshocked region formed by colliding winds of the components by a Miravariable. The orbital period of the Mira is certainly longer than theinterval of observations of 28 years. Our CCD IR data clearly show thepulsation of the Mira variable. It is shown that the nova-like outburstof HM Sge was triggered by a mass-transfer burst from the Mira variableto the hot component during its periastron passage on an eccentricorbit. These mass-transfer bursts were reponsible also for thepostoutburst activity of the system.
| A Study of the Shell of Nova V705 Cas
Spectroscopic observations of the DQ Her-type Nova V705 Cas in thewavelength range H_gamma - 7400 A at the nebular stage are presented.The Balmer decrement yields E_(B-V) = 0.98. Based on statisticalrelationships, we estimated E_(B-V) to be 0.7 and the distance to theNova to be 1.17 kpc. The discrepancy between the estimates of E_(B-V)may result from circumstellar reddening after the formation of a dustshell. The helium, oxygen, nitrogen, argon, iron, and calcium abundancesin the Nova shell are determined. The shell of V705 Cas is similar inchemical composition to those of other DQ Her-type novae.
| 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.
| New Photometric Sequence for Hm-Sagittae
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| Carbon Stars in Two Northern Milky way Zones.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1957ApJ...125..195N&db_key=AST
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