31 research outputs found
Recurrent mini-outbursts and a magnetic white dwarf in the symbiotic system FN Sgr
AIMS: We investigated the optical variability of the symbiotic binary FN Sgr,
with photometric monitoring during 55 years and with a high-cadence
Kepler light curve lasting 81 days. METHODS: The data obtained in the V and I
bands were reduced with standard photometric methods. The Kepler data were
divided into subsamples and analyses with the Lomb-Scargle algorithm. RESULTS:
The V and I band light curves showed a phenomenon never before observed with
such recurrence in any symbiotic system, namely short outbursts, starting
between orbital phase 0.3 and 0.5 and lasting about a month, with a fast rise
and a slower decline, and amplitude of 0.5-1 mag. In the Kepler light curve we
discovered three frequencies with sidebands. We attribute a stable frequency of
127.5 d (corresponding to an 11.3 minutes period) to the white dwarf
rotation. We suggest that this detection probably implies that the white dwarf
accretes through a magnetic stream, like in intermediate polars. The small
outbursts may be ascribed to the stream-disc interaction. Another possibility
is that they are due to localized thermonuclear burning, perhaps confined by
the magnetic field, like recently inferred in intermediate polars, albeit on
different timescales. We measured also a second frequency around 116.9 d
(corresponding to about 137 minutes), which is much less stable and has a
drift. It may be due to rocky detritus around the white dwarf, but it is more
likely to be caused by an inhomogeneity in the accretion disk. Finally, there
is a third frequency close to the first one that appears to correspond to the
beating between the rotation and the second frequency.Comment: Accepted for publication in Astronomy and Astrophysic
Phytodiversity of temperate permanent grasslands: ecosystem services for agriculture and livestock management for diversity conservation
New magnetic anomalies of the Outer Carpathians in NE Slovakia and their relationship to the Carpathian Conductivity Zone
A hitherto unknown magnetic anomaly has been detected in the framework of assembling magnetic picture of the Slovakian territory. The impressive magnetic object was recognized in the northeasternmost part of Slovakia within the area which is created by sediments of the Flysch belt. This is certain rarity because the Flysch sequence is practically without magnetic rocks. Due to this was obvious that anomaly is caused by an exotic rocks complex, intruded into Flysch sediments. The shape and the character of anomalous body indicated that source of anomaly is located in the shallow depth under surface relatively. The anomaly has been modelled in the 2D. Source of magnetic anomaly was interpreted as the product of Neogene volcanism – neck of intermediate rocks. Besides of this there were found out other minor anomalies within this area which might be caused also by smaller subvolcanic bodies. The Carpathian Conductivity Anomaly is located in the proximity of new observed magnetic anomalies. Due to this fact it is possible to open new view on the importance of this zone. In the case of justification of such interpretation the area might be interesting for its potential prognosis of hydrocarbons occurrence, metallogenetic prominence, as well as possibilities for underground storage of carbon dioxide
Adoption of the ecosystem services concept in EU policies
The concept of ecosystem services has gained a strong political profile during the last 15 years. However, there is no specific EU policy devoted to the governing of ecosystem services. This article shows that the ecosystem services concept is already embedded in recent EU (environmentally-related) policies, such as the Biodiversity Strategy 2020 and the Invasive Alien Species Regulation. A review of 12 policies shows that, overall, the coherence between existing policies and the ecosystem services concept is moderate. Policies showing very high coherence are confined to the policy arenas that address natural ecosystems, forestry, or agriculture. Given the sectoral nature of most EU policies and the limited options for revision in the near future, opportunities for improving coherence are mostly expected in improving the integration of the ecosystem services concept in the implementation of existing EU policies at national and regional levels