We present new optical and infrared photometric observations and high resolution Hα spectra of the periodic radio star LSI+61303. The optical photometric data set covers the time interval 1985-1993 and amounts to about a hundred nights. A period of ∼26 days is found in the V band. The infrared data also present evidence for a similar periodicity, but with higher amplitude of variation (0.2). Th...

Recently, Turaev [19, 20] (see also Le and Turaev [8] and Virelizier [23]) generalized the notion of a TQFT and Reshetikhin-Turaev invariants to the case of 3-manifolds endowed with a homotopy classes of maps to K(π, 1), where π is a group. One of the key points in [19] is the notion of a crossed Hopf π-coalgebra, here called a Turaev coalgebra or, briefly, a T-coalgebra (see Section 1). As one...

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...

Optical spectroscopy and the UV luminosity function of galaxies in the Abell 1367, Coma and Virgo clusters. Abstract. Optical spectroscopy of 93 galaxies, 60 projected in the direction of Abell 1367, 21 onto the Coma cluster and 12 on Virgo, is reported. The targets were selected either because they were detected in previous Hα, UV or r ′ surveys. The present observations bring to 100% the reds...

The properties of the few symbiotic stars detected among the 66 binary S stars from the Henize sample are discussed. Two stars (Hen 18 and Hen 121) exhibit both a strong blue-violet continuum and strong Hα emission (FWHM of 70 km s ), whereas Hen 134 and 137 exhibit weak Hα emission. The Hα profiles are typical of non-dusty symbiotic stars belonging to class S-3 as defined by Van Winckel et al....

We present a series of optical spectroscopic and near-infrared photometric observations of the Be star X Persei, from the beginning of the recent emission phase. Our data show that after the latest extended low state (ELS), both the equivalent width (EW) of the Hα emission line and the JHK luminosities gradually increased. The recent maximum Hα EW and JHK magnitudes are more than but comparable...

[O ii]λ3727Å is often used as a tracer of star formation at intermediate redshifts (z ∼> 0.4), where Hα is not easily observed. We use the spectrophotometric data of the Nearby Field Galaxy Survey to investigate the range and systematic variation in observed [O ii]/Hα emission line ratio as a function of galaxy luminosity at low redshift. We find that the observed [O ii]/Hα ratio varies by a fa...

Immunotherapeutic approaches reducing α-synuclein deposits may provide therapeutic benefit for Dementia with Lewy Bodies (DLB). Immunization with full-length human α-synuclein (hα-Syn) protein in a Parkinson's disease mouse model decreased the accumulation of the aggregated forms of this protein in neurons and reduced neurodegeneration. To enhance the immunogenicity of candidate vaccines and to...

We present the results of a photographic and CCD imaging survey for Herbig–Haro (HH) objects in the L1630 and L1641 giant molecular clouds in Orion. The new HH flows were initially identified from a deep Hα film from the recently commissioned AAO/UKST Hα Survey of the southern sky. Our scanned Hα and broad band R images highlight both the improved resolution of the Hα survey and the excellent c...