منابع مشابه
Permanent Superhumps in Nova V 1974 Cygni 1992
We present results of 32 nights of CCD photometry of V1974 Cygni, from the years 1994 and 1995. We verify the presence of two distinct periodicities in the light curve: 0.0812585 day ≈ 1.95 hours and 0.0849767 d ≈ 2.04 hr. We establish that the shorter periodicity is the orbital period of the underlying binary system. The longer period oscillates with an average value of | ˙ P | ∼ 3 × 10 −7 —ty...
متن کاملThe Optical Spectroscopic Evolution of V1974 Cygni (nova Cygni 1992)
Received ; accepted – 2 – ABSTRACT Optical observations of nova V1974 Cygni (Cygni 1992), spanning a 4 year period, have been used to study its spectroscopic evolution. The data cover a wavelength range from ∼ 3200 − 8000Å and follows the nebular evolutionary phase of the ejecta. We have modeled the integrated fluxes by means of the photoionization code CLOUDY. The models were run at a fixed ab...
متن کاملThe underregistration of neonatal deaths: Georgia 1974--77.
We reviewed the neonatal outcome of 3,369 infants who weighed less than or equal to 1500 grams and who were born in Georgia during the years 1974--76. We matched 1,465 of these infants with a death certificate registered in the State's Vital Records. Upon review of the hospital records of the remaining infants, we identified 453 infants that died during the neonatal period without a death certi...
متن کاملTime series analysis of V 1794 Cygni long–term photometry
Standard Johnson UBVRI photometry of V 1794 Cyg (HD199178) between 1975 and 1995 is analysed. Instead of the traditional constant period ephemeris, we determine the seasonal periodicities (Pphot) and the primary and secondary minima epochs (tmin,1, tmin,2) of the normalized UBVRI magnitudes using the three stage period analysis (TSPA) and complementary methods. Our tmin,1 and tmin,2 estimates w...
متن کاملThe nature and evolution of Nova Cygni 2006 ⋆ , ⋆ ⋆
Aims. Nova Cyg 2006 has been intensively observed throughout its full outburst. We investigate the energetics and evolution of the central source and of the expanding ejecta, their chemical abundances and ionization structure, and the formation of dust. Methods. We recorded low, medium, and/or high-resolution spectra (calibrated into accurate absolute fluxes) on 39 nights, along with 2353 photo...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: International Astronomical Union Colloquium
سال: 1977
ISSN: 0252-9211
DOI: 10.1017/s0252921100080313