139 research outputs found
New powerful outburst of the unusual young star V1318 Cyg S (LkH{\alpha} 225)
Young double star V1318 Cyg, which is associated with a small isolated
star-forming region around HAeBe star BD+40o4124, has very unusual photometric
and spectral behavior. We present results of photometric and spectroscopic
observations in the optical range. We carried out BVRI CCD photometric
observations of V1318 Cyg from 2015 Sept. to 2017 July. For the same period we
acquired medium- and low-resolution spectra. Observations were performed with
the 2.6 m telescope. We analyze the historical light curve for V1318 Cyg and
demonstrate that the southern component, V1318 Cyg S, after being rather bright
in the 1970s (V14 mag) started to lower its brightness and in 1990
became practically invisible in the optical. After its reappearance in the
second half of the 1990s the star started to become very slowly brighter.
Between 2006 and 2010 V1318 Cyg S started brightening more quickly, and in 2015
had become brighter by more than five magnitudes in visible light. Since this
time V1318 Cyg S has remained at this maximum. Its spectrum shows little
variability and consists of a mixture of emission and absorption lines, which
has allowed for estimates of its spectral type as early Ae, with obvious
evidence of matter outflow. We derive its current A(V) 7.2 and L = 750
L(sun) thus confirming that V1318 Cyg S should belong to the Herbig Ae stars,
making it, along with BD+40o4124 and V1686 Cyg, the third luminous young star
in the group. It is very probable that we observe V1318 Cyg S near the pole and
that the inclination of its dense and slow ( 100 km/s) outflow is low.
The unusual variability and other features of V1318 Cyg S make it difficult to
classify this star among known types of eruptive young stars. It could be an
extreme, higher-mass example of an EXor, or an object of intermediate class
between EXors and FUors, like V1647 Ori.Comment: 9 pages, 7 figure
Patterns of mortality in Indigenous adults in the Northern Territory, 1998β2003: are people living in more remote areas worse off?
Objective: ToquantifyIndigenousmortalityintheNorthernTerritorybyremotenessof residence.
Design, setting and participants: Australian Bureau of Statistics mortality data were used to compare rates of death from chronic disease in the NT Indigenous population with rates in the general Australian population over the period 1998β2003. Rates were evaluated by categories of remoteness based on the Accessibility/Remoteness Index of Australia: outer regional areas (ORAs), remote areas (RAs) and very remote areas (VRAs). Main outcome measures: Mortality from cardiovascular disease, diabetes and renal disease; standardised mortality ratios (SMRs); percentage change in annual death rates; changes in mortality between 1998β2000 and 2001β2003.
Results: In 1998β2000, SMRs for all-cause mortality were 285% in ORAs, 875% in RAs and 214% in VRAs. In 2001β2003, corresponding SMRs were 325%, 731% and 208%. For the period 1998β2003, percentage changes in annual all-cause mortality were 4.4% (95% CI, β2.2%, 11.5%) in ORAs, β5.3% (95% CI, β9.6%, β0.8%) in RAs, and 1.1% (95% CI, β7.2%, 11.3%) in VRAs. In 2001β2003, compared with 1998β2000, changes in the number of Indigenous deaths were +35 in ORAs, β37 in RAs and +32 in VRAs. Similar patterns were observed for cardiovascular mortality. Conclusions: ComparedwithmortalityinthegeneralAustralianpopulation,Indigenous mortality was up to nine times higher in RAs, three times higher in ORAs and two times higher in VRAs. The fact that rates were lowest in VRAs runs contrary to claims that increasing remoteness is associated with poorer health status. Despite the high death rate in RAs, there was a downward trend in mortality in RAs over the study period. This was partly attributable to a fall in the absolute number of deaths
Magnetic fields of our Galaxy on large and small scales
Magnetic fields have been observed on all scales in our Galaxy, from AU to
kpc. With pulsar dispersion measures and rotation measures, we can directly
measure the magnetic fields in a very large region of the Galactic disk. The
results show that the large-scale magnetic fields are aligned with the spiral
arms but reverse their directions many times from the inner-most arm (Norma) to
the outer arm (Perseus). The Zeeman splitting measurements of masers in HII
regions or star-formation regions not only show the structured fields inside
clouds, but also have a clear pattern in the global Galactic distribution of
all measured clouds which indicates the possible connection of the large-scale
and small-scale magnetic fields.Comment: 9 pages. Invited Talk at IAU Symp.242, 'Astrophysical Masers and
their Environments', Proceedings edited by J. M. Chapman & W. A. Baa
The predictive value of albuminuria for renal and nonrenal natural deaths over 14 years follow-up in a remote aboriginal community
Background. Australian aboriginal people living in remote regions have extraordinary higher rates of mortality compared with other Australian ethnicities. Albuminuria marks the underlying renal disease. This study assessed the predictive value of albuminuria for nonrenal and renal deaths in a remote Australian aboriginal community over a follow-up period of > 14 years
Decreasing rates of natural deaths in a remote Australian Aboriginal community, 1996-2010
Objective: To examine the trends of all-cause natural mortality for people aged 15 years and over in a remote Australian Aboriginal community between 1996 and 2010. Methods: The annual population in the community by gender and age group was obtained from the Australian Bureau of Statistics (ABS). All known deaths and all records of start of renal replacement therapy (RRT) for renal failure were recorded between 1996 and 2010. Five-year aggregated death rates were calculated and the changes in natural mortality over the interval were evaluated. Mortality was compared with those of the Northern Territory (NT) Indigenous and non-Indigenous people as a whole from 1998 to 2006. Results: Rates of natural deaths were lower in the third interval 2006-2010 relative to the first interval 1996-2000, with higher, but more rapidly falling rates for females than males. Reductions were prominent for both sexes in the 65 and over age groups, but death rates in females of earlier middle age also trended lower. The trends applied whether or not the starting of RRT was considered as a natural death. There was a similar trend in rates of natural death in the aggregate Indigenous population of NT. Conclusions: The downward trends probably reflect improvements in risk factor status since the 1960s, all-of-life health interventions, as well as better chronic disease management in the last two decades. The higher death rates in females than males in this community remain unexplained, but the rapid rate of decline of female death rates predicts that this gap will soon be minimised
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