Ronald Hellings
Ronald Wald Hellings | |
|---|---|
| Born | 23 January 1944 |
| Died | 1 January 2022 (aged 77) |
| Education | Brigham Young University (BS) UCLA (MS) Montana State University (PhD) |
| Occupations | Professor, research scientist |
| Scientific career | |
| Fields | Theoretical astrophysics |
| Workplaces | Southern Oregon University, UNLV, Cal Poly Pomona, Harvey Mudd, JPL, MSU |
Ronald Ward Hellings (23 January 1944 – 1 January 2022) was an American theoretical astrophysicist at Jet Propulsion Laboratory and Montana State University, best known for the Hellings–Downs curve he co-derived with George Downs for detecting the stochastic gravitational wave background using pulsar timing arrays. Hellings' research focused on gravitational wave astronomy and astrophysical tests for modifications to general relativity.[1][2][3]
Career
[edit]In 1983, Hellings and George Downs derived the Hellings–Downs curve.
Hellings also sought to improve astrophysical constraints on deviations from general relativity. In response to a 1974 analysis of lunar motion by Tom Van Flandern which claimed to detect a decreasing gravitational constant, in 1983 Hellings led an analysis of Earth-Mars distance data from the Viking landers which found a null result in tension with Van Flandern.[4][5][6] Hellings also used the Viking data to estimate the masses of Ceres, Pallas, and Vesta from their gravitational effects on Mars.[7]
Hellings was the NASA program scientist for the Joint Dark Energy Mission proposal, which evolved into the Nancy Grace Roman Space Telescope.[8]
Selected publications
[edit]- Hellings, R. W.; Downs, G. S. (1983-02-01). "Upper limits on the isotropic gravitational radiation background from pulsar timing analysis". The Astrophysical Journal. 265: L39. doi:10.1086/183954.
- Backer, D. C.; Hellings, R. W. (1986). "Pulsar Timing and General Relativity". Annual Review of Astronomy and Astrophysics. 24. Annual Reviews: 537–575. doi:10.1146/annurev.aa.24.090186.002541.
References
[edit]- ↑ Backer, D. C.; Hellings, R. W. (1986). "Pulsar Timing and General Relativity". Annual Review of Astronomy and Astrophysics. 24. Annual Reviews: 537–575. doi:10.1146/annurev.aa.24.090186.002541. ISSN 1545-4282.
- ↑ "Ron Hellings, Ph.D - Department of Physics | Montana State University". physics.montana.edu. Retrieved 2026-09-08.
- ↑ "Obituary information for Ronald Ward Hellings, Ph.D." www.dokkennelson.com. Archived from the original on 2026-05-11. Retrieved 2026-09-08.
- ↑ "A clock is a clock is a clock". Science News. 124 (22). Society for Science & the Public, Wiley: 346–346. 1983. doi:10.2307/3968199. ISSN 0036-8423.
- ↑ Robinson, Arthur L. (1983). "New Test of Variable Gravitational Constant". Science. 222 (4630). American Association for the Advancement of Science: 1316–1317. ISSN 0036-8075.
- ↑ Kragh, Helge (2016). Varying Gravity: Dirac's Legacy in Cosmology and Geophysics. Science Networks. Historical Studies (1st ed. 2016 ed.). Cham: Springer International Publishing : Imprint: Birkhäuser. pp. 138–139. doi:10.1007/978-3-319-24379-5. ISBN 978-3-319-24379-5.
- ↑ Murray, Carl (October 2013). "AskAstro". Astronomy. 41 (10): 34 – via 2026-09-08.
- ↑ Battersby, Stephen (2006-08-24). "Latecomer revs up dark energy race". New Scientist. 191 (2564): 8–9. doi:10.1016/S0262-4079(06)60194-2. ISSN 0262-4079.