Search Publications
The Mass of the White Dwarf Companion in the Self-lensing Binary KOI-3278: Einstein versus Newton
Kruse, Ethan; Latham, David W.; Quinn, Samuel N. +10 more
KOI-3278 is a self-lensing stellar binary consisting of a white dwarf secondary orbiting a Sun-like primary star. Kruse & Agol noticed small periodic brightenings every 88.18 days in the Kepler photometry and interpreted these as the result of microlensing by a white dwarf with about 63% of the mass of the Sun. We obtained two sets of spectra …
Colour-dependent accurate modelling of dynamical parallaxes and masses of visual binaries. Application to the VB+SB2 systems with definitive orbits
Andrade, Manuel
Context. Two fundamental characteristics of binary systems are the masses of their components and their distance to the Earth. In this way, the dynamical parallax is an accurate and very helpful tool. Nevertheless, there has been some concern with regard to the use of a unique linear mass-luminosity relation (MLR) for the entire main sequence (MS)…
Jupiter's Dark Polar Region as Observed by the Hubble Space Telescope During the Juno Approach Phase
Nichols, J. D.; Bunce, E. J.; Swithenbank-Harris, B. G.
We present an analysis of Jupiter's dark polar region, previously described as a crescent-shaped region devoid of emission along the dawnside poleward of the main oval. Using ultraviolet images obtained by the Hubble Space Telescope between days of year 137 and 176, coupled with interplanetary data captured during the approach phase of the NASA Ju…
Observational study of hydrocarbons in the bright photodissociation region of Messier 8
Menten, K. M.; Lee, M. -Y.; Wyrowski, F. +3 more
Aims: Hydrocarbons are ubiquitous in the interstellar medium, but their formation is still not well understood, depending on the physical environment in which they are found. Messier 8 (M8) is host to one of the brightest H II regions and photodissociation regions (PDRs) in our galaxy. With the observed C2H and c-C3H
A Chandra Study: Are Dwarf Carbon Stars Spun Up and Rejuvenated by Mass Transfer?
Roulston, Benjamin R.; Green, Paul J.; Anderson, Scott F. +9 more
Carbon stars (with C/O > 1) were long assumed to all be giants, because only asymptotic giant branch (AGB) stars dredge up significant carbon into their atmospheres. The case is nearly ironclad now that the formerly mysterious dwarf carbon (dC) stars are actually far more common than C giants and have accreted carbon-rich material from a former…
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