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The X1 catalogue of positions and proper motions of faint stars around the ICRF sources

Fedorov, P. N.; Myznikov, A. A.

We present a new catalogue of faint astrometric reference stars around ICRF sources of northern hemisphere. The X1 catalogue is obtained at the Institute of Astronomy of the V. N. Karazin Kharkiv National University and contains about 1.3 million positions and proper motions of stars from 10^m to 19^m within 330 1° ×1° fields. Mean positions and p…

A Study of Orientation and Motion of Flux Transfer Events Observed at High-Latitude Dayside Magnetopause

Balogh, A.; Daly, P. W.; Reme, H. +4 more

This paper investigates 13 FTEs, which were detected by Cluster II in magnetosheath near the cusp region during February to March 2001. The orientation of the FTE tube axis is derived by virtue of minimum variance analysis (MVA) using magnetic field data from the four Cluster spacecraft. Of the 13 events, 6 axis directions are determined reliably,…

The field of IC 2602: Strömgren-Hβ photometry approach

Kaltcheva, N.; Jaeger, S.; Kaba Bah, M. +1 more

A homogeneous data-base collating all uvbyβ photometry available at present for O-B9 stars in the field of IC 2602 is presented. The characteristics of the field are studied. Four spatially coherent groups can be distinguished. A low reddened compact group located at 156±6 pc is identified with IC 2602, followed by background layers at 546±33 pc, …

The Exploration of the Heliosphere in Three Dimensions with Ulysses - A Case Study in International Cooperation

Fisk, L. A.

UV radiation as biologic limit in the origin and development of life in extrasolar planets

Buccino, A. P.; Mauas, P. J. D.; Lemarchand, G. A.

In this work, we displayed a new biological criterion that restricts the traditional habitable zone. We set the internal boundary of this new UV habitable zone from the maximum radiation that tolerates the DNA and its external boundary from the levels of UV radiation needed in the biogenesis processes. We also analyzed the evolution of the habitab…

The accretion/ejection paradigm of low mass stars tested with HST

Ray, T. P.; Eislöffel, J.; Bacciotti, F. +2 more

In the last few years new investigation techniques have allowed us to study in depth the spectacular phenomenon of protostellar jets, and to test the validity of the proposed models for their acceleration. In this contribution we review the current knowledge on the subject, with a special emphasis on the recent achievements obtained thanks to obse…

The astrobiological aspects of Titan: A new vision from Cassini-Huygens

Israel, G.; Owen, T.; Raulin, F. +1 more

Electron pitch angle variations recorded at the high magnetic latitude boundary layer by the NUADU instrument on the TC-2 spacecraft

Barabash, S.; Gunell, H.; Brinkfeldt, K. +16 more

The NUADU (NeUtral Atom Detector Unit) experiment aboard TC-2 recorded, with high temporal and spatial resolution, 4π solid angle images of electrons (~50-125 keV) spiraling around geomagnetic field lines at high northern magnetic latitudes (L>10), during its in-orbit commissioning phase (September 2004). The ambient magnetic field, as well as …

An Outburst Detected in the Spectrum of Hd 6226

Šlechta, Miroslav; Škoda, Petr

HD 6226 is a bright binary Be star at visual magnitude 6.81 (Hipparcos database). The emission and absorption phases occur in cycles, which are probably not periodic. The suspected period of about 630 days (derived from photometric measurements) is not confirmed by our spectroscopic survey. The latest emission phase developed in the beginning of 2…

Discovery and study of Comet 67P/Churyumov--Gerasimenko, the main target of the Rosetta space mission

Churyumov, K.

Rosetta, a European space vehicle, which was 15 years in development, headed for short-period Comet 67P/Churyumov-Gerasimenko in February 2004. In September 1969 S. Gerasimenko and the author went to the Alma-Ata Astrophysical Institute to carry out a survey of short-period and new comets. At a later date of that month, the author examined the exp…