An Ensemble Study of a January 2010 Coronal Mass Ejection (CME): Connecting a Non-obvious Solar Source with Its ICME/Magnetic Cloud

A distinct magnetic cloud (MC) was observed in-situ at the Solar TErrestrial RElations Observatory (STEREO)-B on 20?–?21 January 2010. About three days earlier, on 17 January, a bright flare and coronal mass ejection (CME) were clearly observed by STEREO-B, which suggests that this was the progenitor of the MC. However, the in-situ speed of the event, several earlier weaker events, heliospheric imaging, and a longitude mismatch with the STEREO-B spacecraft made this interpretation unlikely. We searched for other possible solar eruptions that could have caused the MC and found a faint filament eruption and the associated CME on 14?–?15 January as the likely solar source event. We were able to confirm this source by using coronal imaging from the Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI)/EUVI and COR and Solar and Heliospheric Observatory (SOHO)/Large Angle and Spectrometric Coronograph (LASCO) telescopes and heliospheric imaging from the Solar Mass Ejection Imager (SMEI) and the STEREO/Heliospheric Imager instruments. We use several empirical models to understand the three-dimensional geometry and propagation of the CME, analyze the in-situ characteristics of the associated ICME, and investigate the characteristics of the MC by comparing four independent flux-rope model fits with the launch observations and magnetic-field orientations. The geometry and orientations of the CME from the heliospheric-density reconstructions and the in-situ modeling are remarkably consistent. Lastly, this event demonstrates that a careful analysis of all aspects of the development and evolution of a CME is necessary to correctly identify the solar counterpart of an ICME/MC.     

“Isotopic footprints” of gamma-ray and proton events and anomalous signal in radiocarbon in 775 AD

The production of the cosmogenic radionuclides ¹⁴C, ¹⁰Be, and ³⁶Cl in the Earth’s atmosphere under the action of powerful impulsive proton and gamma-ray events (superpowerful solar flares and Galactic gamma-ray bursts) is considered. The possible “isotopic footprint” in natural archives (the concentrations of these isotopes in dated polar ice cores and annual tree rings) has been calculated by taking into account geophysical processes. The results obtained have been applied to analyzing the anomalous increase in the concentration of radiocarbon measured in tree rings dated 774–775 AD. Arguments for the fact that the most likely cause of this increase is the high-energy emission from a Galactic gamma-ray burst are adduced.     

Serendipitous UV source catalogues for 10 years of XMM and 5 years of Swift

Two UV serendipitous source catalogues are presented which were compiled based on the observations with two similar UV telescopes, one being on-board the ESA’s XMM Newton observatory and another—on-board the NASA’s Swift satellite. Both telescopes have similar optical and registration systems providing photometry in three ultraviolet and three visible bands. After processing a 10 years long series of observations from XMM and 5 years from Swift, we have compiled two source catalogues containing more than 4 million sources for XMM and 6 million sources for Swift. We describe the processing algorithms and present catalogue characteristics in comparison with each other.     

Statistical Analysis of Large-Scale EUV Waves Observed by STEREO/EUVI

We statistically analyzed the kinematical evolution and wave pulse characteristics of 60 strong large-scale EUV wave events that occurred during January 2007 to February 2011 with the STEREO twin spacecraft. For the start velocity, the arithmetic mean is 312±115 km?s^?1 (within a range of 100?–?630 km?s^?1). For the mean (linear) velocity, the arithmetic mean is 254±76 km?s^?1 (within a range of 130?–?470 km?s^?1). 52 % of all waves under study show a distinct deceleration during their propagation (a≤?50 m?s^?2), the other 48 % are consistent with a constant speed within the uncertainties (?50≤a≤50 m?s^?2). The start velocity and the acceleration are strongly anticorrelated with c≈?0.8, i.e. initially faster events undergo stronger deceleration than slower events. The (smooth) transition between constant propagation for slow events and deceleration in faster events occurs at an EUV wave start-velocity of v≈230 km?s^?1, which corresponds well to the fast-mode speed in the quiet corona. These findings provide strong evidence that the EUV waves under study are indeed large-amplitude fast-mode MHD waves. This interpretation is also supported by the correlations obtained between the peak velocity and the peak amplitude, impulsiveness, and build-up time of the disturbance. We obtained the following association rates of EUV wave events with other solar phenomena: 95 % are associated with a coronal mass ejection (CME), 74 % to a solar flare, 15 % to interplanetary type II bursts, and 22 % to coronal type II bursts. These findings are consistent with the interpretation that the associated CMEs are the driving agents of the EUV waves.     

Baroresistor effect and semiconductor thin-film baroresistors based on samarium sulfide for spacecraft applications

The paper describes the dependence of the piezoresistance of the hydrostatic compression of the SmS baroresistor on mechanical properties of the electrical part of the carrier. Isotropic and anisotropic materials are considered that can serve as a baroresistor carrier.     

Dust Detection by the Wave Instrument on STEREO: Nanoparticles Picked up by the Solar Wind?

Solar Physics - The STEREO wave instrument (S/WAVES) has detected a very large number of intense voltage pulses. We suggest that these events are produced by impact ionisation of nanoparticles...     

Planetary transit observations at the University Observatory Jena: XO‐1b and TrES‐1

We report on observations of transit events of the transiting planets XO‐1b and TrES‐1 with a 25 cm telescope of the University Observatory Jena. With the transit timings for XO‐1b from all 50 available XO, SuperWASP, Transit Light Curve (TLC)‐Project‐ and Exoplanet Transit Database (ETD)‐data, including our own I ‐band photometry obtained in March 2007, we find that the orbital period is P = (3.941501 ± 0.000001) d, a slight change by ∼3 s compared to the previously published period. We present new ephemeris for this transiting planet. Furthermore, we present new R ‐band photometry of two transits of TrES‐1. With the help of all available transit times from literature this allows us to refine the estimate of the orbital period: P = (3.0300722 ± 0.0000002) d. Our observations will be useful for future investigations of timing variations caused by additional perturbing planets and/or stellar spots and/or moons (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

The evolution of 1.40M θ pure He star

The evolution of 1.40M pure He star is calculated from the stage of the ignition in the center up to the very advanced stage of evolution where mass ejection by the very luminous He shell could occur. It is found that C¹² does not ignite by a modest margin. Subsequent evolution and relation to the central stars of planetary nebulae is discussed.     

About the first integrals of the generalized problem of translatory-rotary motion of rigid bodies

The existence of ten first integrals for the classical problem of the motion of a system of material points, mutually attracting according to Newtonian law, is well known.The existence of the analogous ten first integrals for the more complicated problem of the motion of a system of absolutely rigid bodies, whose elementary particles mutually attract according to the Newtonian law, was established by the author (Duboshin, 1958, 1963, 1968).In his later papers (Duboshin, 1969, 1970), the problem of the motion of a system of material points, attracting each other according to a more general law, was considered and, in particular, it was shown under what conditions the ten first integrals, analogous to the classical integrals, may exist for this problem.In the present paper, the generalized problem of translatory-rotatory motion of rigid bodies, whose elementary particles acting upon each other according to arbitrary laws of forces along the straight line joining them, is discussed.The author has shown that the first integrals for this general problem, analogous to the integrals of the problem of the translatory-rotatory motion of rigid bodies, whose elementary particles acting according to the Newtonian law, exist under certain well known conditions.That is, it has been established that if the third axiom of dynamics (action = reaction) is satisfied, then the integrals of the motion of centre of inertia and the integrals of the moment of momentum exist for this generalized problem.If the third axiom is not satisfied, then the above mentioned integrals do not exist.The third axiom is a necessary but not a sufficient condition for the existence of the tenth integral-the energy integral. The tenth integral always exists if the elementary particles of the bodies acting with a force, depend only on the mutual distances between them. In this case the force function exists for the problem and the energy integral can be expressed in a well known form.The tenth integral may exist for some more general case, without expressing the principle of conservation of energy, but permitting calculation of the kinetic energy, if the configuration of a system is given.The problem, in which the elementary particles acting according to the generalized Veber's law (Tisserand, 1896) has been cited as an example of this more general case.     

On the interpretation of the π-component splitting in sunspot spectra

It is shown that in order to explain the observed splitting of the -component in the sunspot umbra spectrum by the hypothesis of the coexistence in sunspots of weak- and strong-field regions with opposite polarities, one has to admit the additional assumption that in the weak-field regions the Doppler halfwidth ( _D) and the ratio between line opacity and continuum opacity ( ₀) are both less than those in the strong-field regions.