Orbital period changes of YY Coronae Borealis
نویسندگان
چکیده
منابع مشابه
Fluorine in R Coronae Borealis Stars
Neutral fluorine (F i) lines are identified in the optical spectra of several RCoronae Borealis stars (RCBs) at maximum light. These lines provide the first measurement of the fluorine abundance in these stars. Fluorine is enriched in some RCBs by factors of 800 to 8000 relative to its likely initial abundance. The overabundances of fluorine are evidence for the synthesis of fluorine. These res...
متن کاملWinds in R Coronae Borealis Stars
We present new spectroscopic observations of the He I λ10830 line in R Coronae Borealis (RCB) stars which provide the first strong evidence that most, if not all, RCB stars have winds. It has long been suggested that when dust forms around an RCB star, radiation pressure accelerates the dust away from the star, dragging the gas along with it. The new spectra show that nine of the ten stars obse...
متن کاملH α variability of the recurrent nova T Coronae Borealis ⋆
We analyze Hα observations of the recurrent nova T CrB obtained during the last decade. For the first time the Hα emission profile is analyzed after subtraction of the red giant contribution. Based on our new radial velocity measurements of the Hα emission line we estimate the component masses of T CrB. It is found that the hot component is most likely a massive white dwarf. We estimate the inc...
متن کاملUBV JHKLM photometry and modeling of R Coronae Borealis
We present the results of UBV JHKLM photometry of RCrB spanning the period from 1976 to 2001. Studies of the optical light curve have shown no evidence of any stable harmonics in the variations of the stellar emission. In the L band we found semi-regular oscillations with the two main periods of ∼ 3.3 yr and ∼ 11.9 yr and the full amplitude of ∼ 0. 8 and ∼ 0. 6, respectively. The colors of the ...
متن کاملThe RV-variations of γ Coronae Borealis – a frequency analysis
We summarize a longer campaign of spectroscopic observations of the suspected Maia variable star γ CrB . Previously published data are complemented by two-longitudinal observations. We investigate 1262 CCD spectra for short-term radial velocity variations. Results show that A0 stars can pulsate with periods quite similar to those of the well-known δ Scu stars. From a frequency analysis of the d...
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: Publications of the Astronomical Society of Japan
سال: 2015
ISSN: 0004-6264,2053-051X
DOI: 10.1093/pasj/psv014