Abundance Analysis of R CrB Variable UW Cen
نویسندگان
چکیده
منابع مشابه
Abundance similarities between the R CrB star V854 Cen and the born-again Sakurai’s object
The elemental abundances of the mildly hydrogendeficient R Coronae Borealis (RCrB) star V854Cen have been estimated. The RCrB stars have been divided into majority and minority classes judging by their abundance patterns. Class assignment has previously been unambiguous but V854Cen has traits of both the minority and majority class. Neither V854Cen nor the three obvious minority members show an...
متن کاملDiscovery of Optical Bursts from Ms1603.6+2600 = Uw Crb
We report the discovery of several optical burst-like events from the low-mass X-ray binary MS 1603.6+2600 (UW CrB). The events last for a few tens of seconds, exhibit a very fast rise and slow decay, and involve optical brightening of a factor of 2–3. The flares appear distinct from the lower level flickering and instead strongly resemble reprocessed type-I X-ray bursts as seen in a number of ...
متن کاملRCoronae Borealis Stars at Minimum Light – UW Cen
Two high-resolution optical spectra of the R Coronae Borealis star UW Cen in decline are discussed. A spectrum from mid-1992 when the star had faded by three magnitudes shows just a few differences with the spectrum at maximum light. The ubiquitous sharp emission lines seen in R CrB at a similar drop below maximum light are absent. In contrast, a spectrum from mid-2002 when the star was five ma...
متن کاملThe Variable Quiescence of Cen X - 4
Cen X-4 is one of the best studied low-mass neutron star transients in quiescence. Thanks to XMM-Newton large throughput, Cen X-4 was observed at the highest signal to noise ever. This allowed us to disclose rapid (> 100 s), large (45 ± 7 rms in the 10 −4 − 1 Hz range) intensity variability, especially at low energies. In order to highlight the cause of this variability, we divided the data int...
متن کاملR-process Abundance Signatures
Abundance observations indicate the presence of rapid-neutron capture (i.e., rprocess) elements in old Galactic halo and globular cluster stars. These observations demonstrate that the earliest generations of stars in the Galaxy, responsible for neutron-capture synthesis and the progenitors of the halo stars, were rapidly evolving. Abundance comparisons among large numbers of stars provide clue...
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: 1985
ISSN: 0252-9211
DOI: 10.1017/s0252921100090734