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Discovery of enrichment of the envelopes of post-AGB stars with heavy
metals
As a result of monitoring carried out at the BTA telescope, a new
phenomenon was discovered in the optical spectra of post-AGB supergiants
with an emission at 21 ?m and an overabundance of carbon and heavy metals
in the atmospheres - the splitting of the strongest absorption lines. The
effect is strongest in the high-latitude supergiant V5112 Sgr, in whose
spectrum the BaII lines are split into three components. It is shown that
the short-wavelength components of the split absorptions are formed in
the structured circumstellar envelope. Thus, we discovered for the first
time the enrichment of the stellar envelope with heavy metals synthesized
by the s-process.
(Contact - Klochkova V.G.).
Published:
V.G.Klochkova. Detection of heavy-metal lines in the spectrum of the
circumstellar envelope of a post-AGB star. Astronomy Letters, 2009,
35, No.7, pp.457-465.
V.G.Klochkova. High-latitude supergiant V5112 Sgr: Enrichment of the
envelope with heavy s-process metals. Astronomy Letters, 2013, 39, No.11,
pp.765-775.
Detection of sub-second spikes in the giant optical flare of UV Ceti
About a dozen spikes with a duration of 0.6-1.2 seconds were discovered
for the first time during the monitoring of the flare star UV Ceti at
the 6-m telescope equipped with the MANIA complex. The events are
localized in the vicinity of the maximum of the giant flare and may
have a synchrotron or bremsstrahlung nature.
(Contact - G.M.Beskin).
The result was reported at the European Week of Astronomy and Space
Science 2013 (EWASS) conference, Turku, June 8-13, 2013. The publication
is in preparation to appear in MNRAS.
Discovery of new binary and multiple star systems with magnetic
components
Speckle interferometric observations of 273 magnetic stars were carried
out at the 6-m BTA telescope of SAO RAS. We fully investigated the northern
part (δ>-30o) of the sample of stars with confirmed
global magnetic fields. As a result of high angular resolution (R=0.0022")
observations in a 4.4x4.4" field, 28 new binary and 2 triple stars were
discovered. We resolved 63 objects into individual components: 58 binary
and 5 triple systems. Almost half of the resolved systems were discovered
for the first time. Some of these objects may turn out to be subsystems
in higher-order stellar systems.
(Contact - Rastegaev D.A.).
Published:
D.A.Rastegaev, Yu.Yu.Balega, V.V.Dyachenko, A.F.Maksimov, E.V.Malogolovets,
"Speckle-interferometry of magnetic stars at the BTA. II. Results of
2010-2012 observations", Astrophysical Bulletin, 2014, Volume 69, Issue 1
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