Theses
- Stockman, L.M. (1990). Unstructured Sparse Matrix Dense Vector Multiplication on the DAP. [Unpublished Master of Science Degree Project]. Queen Mary and Westfield College, University of London.
Refereed Papers
- Roxburgh, I.W., Stockman, L.M. (1999). Power series solutions of the polytrope equations. Monthly Notices of the Royal Astronomical Society, 303, 466–470. https://doi.org/10.1046/j.1365-8711.1999.02219.x
Book Articles/Chapters
- Stockman, L.M. (2017). Monthly Sky Notes. In B. Jones (Ed.), Yearbook of Astronomy 2018 (pp. 79–141). White Owl.
- Stockman, L.M. (2018). Monthly Sky Notes. In B. Jones (Ed.), Yearbook of Astronomy 2019 (pp. 83–146). White Owl.
- Stockman, L.M. (2018). The Planets in 2019. In B. Jones (Ed.), Yearbook of Astronomy 2019 (pp. 76–77). White Owl.
- Stockman, L.M. (2018). Some Events in 2019. In B. Jones (Ed.), Yearbook of Astronomy 2019 (pp. 80–82). White Owl.
- Stockman, L.M. (2019). Monthly Sky Notes. In B. Jones (Ed.), Yearbook of Astronomy 2020 (pp. 87–182). White Owl.
- Stockman, L.M. (2019). The Planets in 2020. In B. Jones (Ed.), Yearbook of Astronomy 2020 (pp. 78–80). White Owl.
- Stockman, L.M. (2019). Some Events in 2020. In B. Jones (Ed.), Yearbook of Astronomy 2020 (pp. 84–86). White Owl.
- Stockman, L.M. (2020). Monthly Sky Notes. In B. Jones (Ed.), Yearbook of Astronomy 2021 (pp. 87–178). White Owl.
- Stockman, L.M. (2020). The Planets in 2021. In B. Jones (Ed.), Yearbook of Astronomy 2021 (pp. 78–80). White Owl.
- Stockman, L.M. (2020). Some Events in 2021. In B. Jones (Ed.), Yearbook of Astronomy 2021 (pp. 83–85). White Owl.
- Stockman, L.M. (2021). The Astronomers’ Stars: A Study in Scarlet. In B. Jones (Ed.), Yearbook of Astronomy 2022 (pp. 238–248). White Owl.
- Stockman, L.M. (2021). Monthly Sky Notes. In B. Jones (Ed.), Yearbook of Astronomy 2022 (pp. 87–165). White Owl.
- Stockman, L.M. (2021). The Planets in 2022. In B. Jones (Ed.), Yearbook of Astronomy 2022 (pp. 78–80). White Owl.
- Stockman, L.M. (2021). Some Events in 2022. In B. Jones (Ed.), Yearbook of Astronomy 2022 (pp. 81–83). White Owl.
- Stockman, L.M. (2022). The Astronomers’ Stars: Life in the Fast Lane. In B. Jones (Ed.), Yearbook of Astronomy 2023 (pp. 258–268). White Owl.
- Stockman, L.M. (2022). Monthly Sky Notes. In B. Jones (Ed.), Yearbook of Astronomy 2023 (pp. 95–165). White Owl.
- Stockman, L.M. (2022). The Planets in 2023. In B. Jones (Ed.), Yearbook of Astronomy 2023 (pp. 78–80). White Owl.
- Stockman, L.M., Harper, D. (2022). Shining a Light on Jupiter’s Atmosphere. In B. Jones (Ed.), Yearbook of Astronomy 2023 (pp. 141–143). White Owl.
- Stockman, L.M. (2022). Some Events in 2023. In B. Jones (Ed.), Yearbook of Astronomy 2023 (pp. 89–93). White Owl.
- Stockman, L.M. (2023). The Astronomers’ Stars: In the Neighbourhood. In B. Jones (Ed.), Yearbook of Astronomy 2024 (pp. 298–305). White Owl.
- Stockman, L.M. (2023). Gone But Not Forgotten: Musca Borealis. In B. Jones (Ed.), Yearbook of Astronomy 2024 (pp. 163–166). White Owl.
- Stockman, L.M. (2023). Monthly Sky Notes. In B. Jones (Ed.), Yearbook of Astronomy 2024 (pp. 91–169). White Owl.
- Stockman, L.M. (2023). Lunar Occultations in 2024. In B. Jones (Ed.), Yearbook of Astronomy 2024 (pp. 87–88). White Owl.
- Stockman, L.M. (2023). The Planets in 2024. In B. Jones (Ed.), Yearbook of Astronomy 2024 (pp. 78–80). White Owl.
- Stockman, L.M. (in preparation). The Astronomers’ Stars: The Terrible Twos. In B. Jones (Ed.), Yearbook of Astronomy 2025. White Owl.
- Stockman, L.M. (in preparation). Gone But Not Forgotten: Anser. In B. Jones (Ed.), Yearbook of Astronomy 2025. White Owl.
- Stockman, L.M. (in preparation). Lunar Phenomena. In B. Jones (Ed.), Yearbook of Astronomy 2025. White Owl.
- Stockman, L.M. (in preparation). Monthly Sky Notes. In B. Jones (Ed.), Yearbook of Astronomy 2025. White Owl.
- Stockman, L.M. (in preparation). The Planets in 2025. In B. Jones (Ed.), Yearbook of Astronomy 2025. White Owl.
- Stockman, L.M. (in preparation). Full Moon Names: A Full Moon by any other name would shine as bright. In B. Jones & K. Evans (Eds.), Not Only Through the Telescope. White Owl.
- Stockman, L.M. (in preparation). The Astronomers’ Stars: Taking It To Extremes. In B. Jones (Ed.), Yearbook of Astronomy 2026. White Owl.
- Stockman, L.M. (in preparation). Gone But Not Forgotten: Argo Navis. In B. Jones (Ed.), Yearbook of Astronomy 2026. White Owl.
- Stockman, L.M. (in preparation). The Astronomers’ Stars: Across the Spectrum. In B. Jones (Ed.), Yearbook of Astronomy 2027. White Owl.
- Stockman, L.M. (in preparation). Gone But Not Forgotten: Corona Meridiana. In B. Jones (Ed.), Yearbook of Astronomy 2027. White Owl.
- Stockman, L.M. (in preparation). The Astronomers’ Stars: The Inconstant Stars. In B. Jones (Ed.), Yearbook of Astronomy 2028. White Owl.
- Stockman, L.M. (in preparation). Gone But Not Forgotten: Quadrans Muralis. In B. Jones (Ed.), Yearbook of Astronomy 2028. White Owl.
- Stockman, L.M. (in preparation). The Astronomers’ Stars: Amateur Hour. In B. Jones (Ed.), Yearbook of Astronomy 2029. White Owl.
- Stockman, L.M. (in preparation). Gone But Not Forgotten: Felis. In B. Jones (Ed.), Yearbook of Astronomy 2029. White Owl.
- Stockman, L.M. (in preparation). The Astronomers’ Stars: Going Out With a Bang. In B. Jones (Ed.), Yearbook of Astronomy 2030. White Owl.
- Stockman, L.M. (in preparation). Gone But Not Forgotten: Sceptrum Brandenburgicum. In B. Jones (Ed.), Yearbook of Astronomy 2030. White Owl.
Abstracts
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.
Power series solutions of the polytrope equations
Monthly Notices of the Royal Astronomical Society, 303, 466–470, https://doi.org/10.1046/j.1365-8711.1999.02219.x
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.
The Astronomers’ Stars
Yearbook of Astronomy 2022, 2023, 2024
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.
| Star | Astronomer(s) | Year(s) | Article |
|---|---|---|---|
| Anthelme’s Star | Voituret Anthelme | 1670 | Going Out with a Bang |
| Argelander’s Second Star | Friedrich W.A. Argelander | 1857 | Life in the Fast Lane |
| Argelander’s Star | Friedrich W.A. Argelander | 1841 | Life in the Fast Lane |
| Babcock’s Magnetic Star | Horace W. Babcock | 1960 | Taking It To Extremes |
| Barnard’s Star | Edward E. Barnard | 1916 | Life in the Fast Lane |
| Becklin-Neugebauer Object | Eric E. Becklin, Gerhart Neubegauer | 1967 | Taking It To Extremes |
| Bessel’s Star, Piazzi’s Flying Star | Friedrich W. Bessell, Guiseppe Piazzi | 1838, 1803 | Life in the Fast Lane |
| Bidelman’s Helium Variable Star | William P. Bidelman | 1965 | Across the Spectrum |
| Bidelman’s Peculiar Star | William P. Bidelman | 1950 | Across the Spectrum |
| Bond’s Flare Star | Howard E. Bond | 1976 | The Inconstant Stars |
| Boyajian’s Star, Tabby’s Star | Tabetha S. Boyajian | 2016 | Amateur Hour |
| Branchett’s Object | David Branchett | 1981 | Amateur Hour |
| Butler’s Flare Star | Christopher J. Butler | 1966 | The Inconstant Stars |
| Caffau’s Star | Elisabetta Caffau | 2011 | Across the Spectrum |
| Campbell’s Hydrogen Star | William W. Campbell | 1893 | Across the Spectrum |
| Cayrel’s Star | Roger Cayrel | 2001 | Across the Spectrum |
| Chanal’s Object | Roger Chanal | 1984 | Amateur Hour |
| Chèvremont’s Variable Star | A. Chèvremont | 1897 | Amateur Hour |
| Dahlgren’s Nova | Elis Dahlgren | 1963 | Amateur Hour |
| Herschel’s Garnet Star | F. William Herschel | 1783 | A Study in Scarlet |
| Herschel’s Ruby Star | John F.W. Herschel | 1847 | A Study in Scarlet |
| Hind’s Crimson Star | John R. Hind | 1845 | A Study in Scarlet |
| Hulse-Taylor Pulsar | Russell A. Hulse, Joseph H. Taylor | 1975 | The Terrible Twos |
| Innes’ Star | Robert T.A. Innes | 1920 | In the Neighbourhood |
| Kapteyn’s Star | Jacobus C. Kapteyn | 1897 | Life in the Fast Lane |
| Kepler’s Supernova | Johannes Kepler | 1604 | Going Out with a Bang |
| Krzemiński’s Star | Wojceich Krzemiński | 1974 | The Terrible Twos |
| Kuwano’s Object, Kuwano-Honda Object | Yoshiyuki Kuwano, Minoru Honda | 1979, 1978 | The Inconstant Stars |
| Luyten’s Star | Willem J. Luyten | 1935 | In the Neighbourhood |
| Merrill’s Star | Paul W. Merrill | 1938 | Taking It To Extremes |
| Pearce’s Star | Joseph A. Pearce | 1926 | The Terrible Twos |
| Persson’s Star | Roger Persson | 2004 | Amateur Hour |
| Plaskett’s Star | John S. Plaskett | 1922 | The Terrible Twos |
| Popper’s Extreme Helium Star | Daniel M. Popper | 1942 | Across the Spectrum |
| Przybylski’s Star | Antoni Przybylski | 1961 | Across the Spectrum |
| Roberts-Altizer Variable | Dorothea Klumpke Roberts, Robert J. Altizer | 1914, 1972 | The Inconstant Stars |
| Rosino’s Object, Rosino-Zwicky Object | Leonido Rosino, Fritz Zwicky | 1961, 1965 | The Inconstant Stars |
| Sakurai’s Object | Yukio Sakurai | 1996 | Amateur Hour |
| Sanduleak’s Star | Nicholas Sanduleak | 1977 | Taking It To Extremes |
| Sanduleak-Pesch Binary | Nicholas Sanduleak, Peter Pesch | 1991 | The Terrible Twos |
| Scholz’s Star | Ralf-Dieter Scholz | 2014 | In the Neighbourhood |
| Sneden’s Star | Christopher Sneden | 1994 | Across the Spectrum |
| Stepanian’s Star | Jivan A. Stepanian | 1979 | The Inconstant Stars |
| Stephenson-Sanduleak Object* | Charles B. Stephenson, Nicholas Sanduleak | 1977 | The Terrible Twos |
| Teegarden’s Star | Bonnard J. Teegarden | 2003 | In the Neighbourhood |
| Tycho’s Supernova | Tycho Brahe | 1573 | Going Out with a Bang |
| Van Biesbroeck’s Star | Georges-Achille Van Biesbroeck | 1944 | Taking It To Extremes |
| van Maanen’s Star | Adriaan van Maanen | 1917 | In the Neighbourhood |