13 research outputs found
The Two Variables in The Triple System HR 6469=V819 Her: One Eclipsing, One Spotted
A complete BV light curve, from 14 nights of good data obtained with the Vanderbilt University-Tennessee State University (VU-TSU) automatic telescope, are presented and solved with the Wilson-Devinney program. Third light is evaluated, with the companion star brighter by 0.58m in V and 0.11m in B. The eclipses are partial. Inferred color indices yield F2 V and F8 V for the eclipsing pair and G8 IV-III for the distant companion star. After removing the variability due to eclipses, we study the residual variability of the G8 IV-III star over the ten years 1982 to 1992. Each yearly light curve is fit with a two-spot model. Three relatively long-lived spots are identified, with rotation periods of 85.9d, 85.9d, and 86.1d. The weak and intermittent variability is understood because the G8 IV-III star has a Rossby number at the threshold for the onset of heavy spottedness
Automated Speckle Interferometry of Known Binaries
Astronomers have been measuring the separations and position angles between
the two components of binary stars since William Herschel began his
observations in 1781. In 1970, Anton Labeyrie pioneered a method, speckle
interferometry, that overcomes the usual resolution limits induced by
atmospheric turbulence by taking hundreds or thousands of short exposures and
reducing them in Fourier space. Our 2022 automation of speckle interferometry
allowed us to use a fully robotic 1.0-meter PlaneWave Instruments telescope,
located at the El Sauce Observatory in the Atacama Desert of Chile, to obtain
observations of many known binaries with established orbits. The long-term
objective of these observations is to establish the precision, accuracy, and
limitations of this telescope's automated speckle interferometry measurements.
This paper provides an early overview of the Known Binaries Project and provide
example results on a small-separation (0.27") binary, WDS 12274-2843 B 228
Microservice Transition and its Granularity Problem: A Systematic Mapping Study
Microservices have gained wide recognition and acceptance in software
industries as an emerging architectural style for autonomic, scalable, and more
reliable computing. The transition to microservices has been highly motivated
by the need for better alignment of technical design decisions with improving
value potentials of architectures. Despite microservices' popularity, research
still lacks disciplined understanding of transition and consensus on the
principles and activities underlying "micro-ing" architectures. In this paper,
we report on a systematic mapping study that consolidates various views,
approaches and activities that commonly assist in the transition to
microservices. The study aims to provide a better understanding of the
transition; it also contributes a working definition of the transition and
technical activities underlying it. We term the transition and technical
activities leading to microservice architectures as microservitization. We then
shed light on a fundamental problem of microservitization: microservice
granularity and reasoning about its adaptation as first-class entities. This
study reviews state-of-the-art and -practice related to reasoning about
microservice granularity; it reviews modelling approaches, aspects considered,
guidelines and processes used to reason about microservice granularity. This
study identifies opportunities for future research and development related to
reasoning about microservice granularity.Comment: 36 pages including references, 6 figures, and 3 table
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The Raymond's Dune Site: Its Place in the History of Southern Northwest Coast Archaeology
The Raymond's Dune site (35CU62) in Curry County, Oregon, is mainly known for a radiocarbon assay of 3,000 ± 90 B.P that for many years was the oldest archaeological radiocarbon date from the southern Northwest Coast. Although often mentioned in the archaeological literature, a comprehensive report on this site was never prepared. This article reconstructs the history of fieldwork at this site, bringing together information about the cultural deposits, pithouse feature, artifacts, and human skeletal remains found there. References to this site by L.S. Cressman and other archaeologists are reviewed and assessed in terms of current information. Although no longer one of the oldest known sites in the region, the Raymond's Dune site retains some importance for its small role in the history of southern Northwest Coast archaeology
The Two Variables in the Triple System HR 6469=V819 Her: One Eclipsing, One Spotted
A complete BV light curve, from 14 nights of good data obtained with the VU-TSU automatic telescope, are presented and solved with the Wilson-Devinney program. Third light is evaluated, with the companion star brighter by 0m.58 in V and 0m.11 in B. The eclipses are partial. Inferred color indices yield F2 V and F8 V for the eclipsing pair and G8 IV-III for the distant companion star. After removing the variability due to eclipses we study the residual variability of the G8 IV-III star over the ten years 1982 to 1992. Each yearly light curve is fit with a two-spot model. Three relatively long-lived spots are identified, with rotation periods of 85d.9, 85d.9, and 86d.1. The weak and intermittent variability is understood because the G8 IV-III star has a Rossby number at the threshold for the onset of heavy spottedness
A Spectroscopic and Photometric Study of 12 BM Camelopardalis
Radial velocities from 1916.95 to 1991.95 and photometry from l979.25, both published and new in this paper, are presented and analyzed. A new solution of the radial velocity curve reveals a new period of 80.90 days and an eccentricity of e = 0.05 +/- 0.02, both very different from the 80.17 days and 0.35 found by Abt et al. (1969). An alternative solution with e = 0 is given because we cannot decide firmly whether or not the small eccentricity is real. We find V sin i = 11.3 +/- 0.3 km/s from Maidanak and 10 unequal depth. 0.048 mins and 0.026 mins. The orbital ephemeris for conjunction (K gisnt behind) is JD(hel.) 2,448,111.1 (+/- 0.4 days ) + 80.898 days (+/- 0.004 days ) E, consistent with both the radial velocities and the photometry. With the ellipticity effect removed, the light curve shows residual variability which we fit with a two-spot model. During the 13 years covered by photometry there were nine different starspots, the largest one producing a light loss of 0.19 mins. Rotation periods for the nine spots ranged from 78.6 +/- 0.5 days to 83.7 +/- 0.4 days from which we concluded that the K giant does rotate synchronously but with a differential rotation coefficient of k = 0.06 +/- 0.01. Lifetimes for the nine spots ranged from 1.1 to greater than 4.2 yr and were consistent with the empirical spot lifetime laws of Hall & Henry (1994). Use of the mass function, the orbital period, the V sin i, the two different ellipticity effect amplitudes, and various logical constraints led to ranges of possible masses, radii and inclinations. The most believable solution was around i = 90 deg, R1 = 24 solar radii, M1 = 1.1 solar mass, and M2 = 0.6 solar mass. THe Rossby number for the K giant is 0.48, small enough compared to the critical value of 0.65 to explain why, though rotating \u27slowly\u27, it does have large spots
Ten Years of Eclipse Timings to Refine the Period of HR 6469=V819 Her
New times of minimum of the eclipsing binary in the triple system HR 6469=V819 Her, 90 altogether between 1982 and 1992 by 21 different observers at 17 different observatories in three different countries, are presented. After correction for the time-delay effect expected to result from the eclipsing pair\u27s motion in the 5.5 year orbit, fitting by least squares yields the following linear ephemeris for times of primary minimum: JD (hel.)=2,448,546.5991+2d.2296296 E. A complete UBV light curve obtained in the summer of 1992 at Braeside Observatory is described as well, the data having been sent to the IAU Comm. 27 Archive, as file No. 271