8 research outputs found
Symbiotic star LL Cassiopeiae
No full textAims.Study of the spectral and photometric properties of
the symbiotic star LL Cas.
Methods.Spectroscopy and photometry.
Results.Spectral and photometric observations of LL Cas were performed in
1986–2006. LL Cas displays a late-type spectrum with TiO
absorbtion bands and emission lines of \ion{He}{ii},
[\ion{O}{iii}], \ion{He}{i} and \ion{H}{i}. Significant
fluctuations of relative intensities of [\ion{O}{iii}], 5007Â Ă…
and \ion{He}{ii}, 4686Â Ă… are revealed. They reflect the changes
of the field of radiation of the ionizing source. Wavelike
variations of the star's light with amplitudes of about 2m–3{\fm}5 are found in the B, V and R bands. They can be ascribed to
the pulsations of the cool giant
Planetary nebula K1-9
No full textThe object K1-9 with strong [\ion{N}{ii}] emission lines
was included in the Perek and Kohoutek Catalogue of Planetary Nebulae, but
later it was considered to be an \ion{H}{ii}
region. Our results show that in addition to the low-excitation emissions there
are \ion{He}{ii} and [\ion{O}{iii}] emission lines in its spectrum, and
the effective
temperature of the central star is more than 54 000 . Thus we conclude
that K1-9 is indeed a planetary nebula. Distribution of
[\ion{O}{iii}]
and [\ion{N}{ii}] emission lines reflect a ring-like structure
with a clear minimum in the centre of the nebula. Hydrogen lines
almost fail to show
the central gap. K1-9 has the backward proper motion with
systemic velocity  km s-1. The central hydrogen
component moves relative to the nebula with a pecular velocity of about
–50 km s-1
