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Flight Operations and Lessons Learned of the Rosetta Alice Ultraviolet Spectrograph
Parker, Joel Wm.; Steffl, Andrew J.; Alan Stern, S. +5 more
Two Long-period Cataclysmic Variable Stars: ASASSN-14ho and V1062 Cyg
Thorstensen, John R.; Paterson, Kerry; Hviding, Raphael E. +5 more
We report spectroscopy and photometry of the cataclysmic variable stars ASASSN-14ho and V1062 Cyg. Both are dwarf novae with spectra dominated by their secondary stars, which we classify approximately as K4 and M0.5, respectively. Their orbital periods, determined mostly from the secondary stars’ radial velocities, proved to be nearly identical, r…
Light propagation in 2PN approximation in the field of one moving monopole II. Boundary value problem
Zschocke, Sven
In this investigation the boundary value problem of light propagation in the gravitational field of one arbitrarily moving body with monopole structure is considered in the second post-Newtonian approximation. The solution of the boundary value problem comprises a set of altogether three transformations: , , and . Analytical solutions of these tra…
Are the Double-mode Bulge RR Lyrae Stars with Identical Period Ratios the Relic of a Disrupted Stellar System?
Rich, R. Michael; Kunder, Andrea; Johnson, Christian I. +6 more
Radial velocities of 15 double-mode bulge RR Lyrae (RR01) stars are presented, 6 of which belong to a compact group of RR01 stars in pulsation space, with the ratio of first-overtone period to fundamental mode period, P fo /P f ∼ 0.74, and P f ∼ 0.44. It has been suggested that these pulsationally clumped RR01…
Young stars raining through the galactic halo: the nature and orbit of price-whelan 1
Martin, Nicolas; Malhan, Khyati; Ibata, Rodrigo A. +3 more
We present radial velocities for five member stars of the recently discovered young (age ≃ 100-150 Myr) stellar system Price-Whelan 1 (PW 1), which is located far away in the Galactic Halo (D≃ 29 kpc, Z≃ 15 kpc), and that is probably associated with the leading arm (LA) of the Magellanic Stream. We measure the systemic radial velocity of PW 1, V
A Comparison of the Chemical Composition of Main-sequence and Giant Stars in the Open Cluster NCC 752
Lum, Michael G.; Boesgaard, Ann Merchant
The chemical composition of stars in open clusters provides the best information on the chemical evolution of stars via comparison of main-sequence stars with evolved giants. This is a case study of the abundances in the dwarfs and giants in the old open cluster NGC 752. It is also a pilot program for automated abundance determinations, including …
Exploring the role of X-ray reprocessing and irradiation in the anomalous bright optical outbursts of A0538-66
Mereghetti, S.; Santangelo, A.; Ducci, L. +2 more
Context. In 1981, the Be/X-ray binary A0538-66 showed outbursts characterized by high peak luminosities in the X-ray (Lx ≈ 1039 erg s-1) and optical (Lopt ≈ 3 × 1038 erg s-1) bands. The bright optical outbursts were qualitatively explained as X-ray reprocessing in a gas cloud surrou…
Global Energetics of Solar Flares. VII. Aerodynamic Drag in Coronal Mass Ejections
Gopalswamy, Nat; Aschwanden, Markus J.
The free energy that is dissipated in a magnetic reconnection process of a solar flare, generally accompanied by a coronal mass ejection (CME), has been considered as the ultimate energy source of the global energy budget of solar flares in previous statistical studies. Here we explore the effects of the aerodynamic drag force on CMEs, which suppl…
Deflections of ultra-high energy cosmic rays by the Milky Way magnetic field: how well can they be corrected?
Pavlidou, V.; Magkos, G.
Locating the sources of ultra-high energy cosmic rays (UHECRs) still remains a difficult puzzle for modern astrophysics. A major hurdle in the search for the sources is the fact that UHECRs are deflected by the Galactic magnetic field (GMF). Current knowledge of the GMF is limited, as most experimental measurements track line-of-sight-integrated q…
Degradation of Endeavour Crater Based on Orbital and Rover-Based Observations in Combination With Landscape Evolution Modeling
Arvidson, R. E.; Grant, J. A.; Wilson, S. A. +3 more
Exploration of Endeavour crater's Shoemaker formation rim rocks by the Opportunity rover, combined with extensive observations from the Mars Express and Mars Reconnaissance Orbiters, provides unique and quantitative insights into the processes that have degraded this 22-km diameter Noachian age impact crater. These insights are informed by compari…