2021Stockman, Lynne MarieThe Astronomers’ Stars: A Study in ScarletYearbook of Astronomy 2022, 238–248
2021Stockman, Lynne MarieMonthly Sky NotesYearbook of Astronomy 2022, 87–165
2021Stockman, Lynne MarieThe Planets in 2022Yearbook of Astronomy 2022, 78–80
2021Stockman, Lynne MarieSome Events in 2022Yearbook of Astronomy 2022, 81–83
2020Stockman, Lynne MarieMonthly Sky NotesYearbook of Astronomy 2021, 87–178
2020Stockman, Lynne MarieThe Planets in 2021Yearbook of Astronomy 2021, 78–80
2020Stockman, Lynne MarieSome Events in 2021Yearbook of Astronomy 2021, 83–85
2019Stockman, Lynne MarieMonthly Sky NotesYearbook of Astronomy 2020, 87–182
2019Stockman, Lynne MarieThe Planets in 2020Yearbook of Astronomy 2020, 78–80
2019Stockman, Lynne MarieSome Events in 2020Yearbook of Astronomy 2020, 84–86
2018Stockman, Lynne MarieMonthly Sky NotesYearbook of Astronomy 2019, 83–146
2018Stockman, Lynne MarieThe Planets in 2019Yearbook of Astronomy 2019, 76–77
2018Stockman, Lynne MarieSome Events in 2019Yearbook of Astronomy 2019, 80–82
2017Stockman, Lynne MarieMonthly Sky NotesYearbook of Astronomy 2018, 79–141
1999Roxburgh, Ian W., Stockman, Lynne M.Power series solutions of the polytope equationsMonthly Notices of the Royal Astronomical Society, 303, 466–470
1990Stockman, Lynne MarieUnstructured Sparse Matrix Dense Vector Multiplication on the DAPMaster of Science Degree Project, Queen Mary and Westfield College, University of London

Abstracts

The Astronomers’ Stars

Yearbook of Astronomy 2022

The stars are ours. Their names reflect our religions, our stories, our calendars, our histories. Some are millennia old, their very origins lost in antiquity; others are of a more recent origin. ŠAR.GAZ (Sargas, θ Scorpii) is the mighty weapon of the Mesopotamian god dAMAR.UTU (Marduk), patron of the city of Babylon. Perseus, hero and legendary founder of Mycenae, slew the Gorgon Medusa; Raʾas al-Ghūl (Algol, β Persei) marks the baleful blinking eye in the head of the ghoul. The heliacal rising of the brightest star in the night sky, Σείριος (Sirius, α Canis Majoris), predicts the onset of the hot, dry days of summer in Greece and the annual flooding of the Nile in Egypt. And Cor Caroli (α Canum Venaticorum), Latin for ‘the heart of Charles’, remembers the execution of English King Charles I in the mid-seventeenth century.

We looked for patterns in the night skies and we named the brightest stars. But some of the stars, most of the stars, evaded our ancestors’ detection. They were transient or faint or otherwise overlooked, and often it took careful and dedicated observation and measurement, sometimes over many years, to bring them into the light. These are the astronomers’ stars.

Power series of the polytrope equations

Monthly Notices of the Royal Astronomical Society, 303, 466–470

We derive recurrence relations for the coefficients ak in the power series expansion θ(ξ) = ∑ ak∙ξ2k of the solution of the Lane-Emden equation, and examine the convergence of these series. For values of the polytropic index n < n1 ~ 1.9 the series appear to converge everywhere inside the star. For n > n1 the series converge in the inner part of the star but then diverge. We also derive the series expansions for θ, ξ in powers of m = q2/3, where q = −ξ2∙dθ/dξ is the polytropic mass. These series appear to converge everywhere within the star for all n ≤ 5. Finally we show that θ(ξ) can be satisfactorily approximated (~1%) by (1 − c∙ξ2)/(1 + e∙ξ2)m, and give the values of the constants determined by a Padé approximation to the series, and by a two-parameter fit to the numerical solutions.

Unstructured Sparse Matrix Dense Vector Multiplication on the DAP

Master of Science Degree Project, Queen Mary and Westfield College, University of London, August 1990

The DAP mentioned in the title and the abstract is the Applied Memory Technology Distributed Array Processor which is a massively parallel computer of single instruction multiple data (SIMD) architecture. The DAP 600 series machine which I used in my research had 4096 single-bit processing elements arranged in a 64 × 64 array, and was attached to a host computer, in this case a Digital Equipment Corporation VAX 8350. The host machine handled all input and output as well as data transfer to and from the DAP. The host programs were written in FORTRAN 77 and the DAP programs were written in FORTRAN-PLUS, a dialect of FORTRAN specific to the DAP.

The development and ever-increasing use of parallel computers have forced programmers to re-examine even the most basic mathematical algorithms and computational techniques in order to efficiently adapt these procedures to new computer architectures. Matrix vector multiplication is a familiar algorithm and has been implemented successfully on a variety of parallel computers. However, sparse matrices, which are common in many application areas, can be difficult to deal with in parallel because of their packed storage representations. This paper examines sixteen unstructured sparse matrix dense vector multiplication algorithms, all specifically tailored to the DAP.