145451 Rumina

Scattered disc object 145452 Ritona yes #C2E0FF 145451 Rumina Rumina Hubble 2008.png Rumina imaged by the Hubble Space Telescope on 2 November 2008 A. C. BeckerA. W. PuckettJ. M. Kubica 9 September 2005 Apache Point Obs. 48.18 yr (17,596 d) 17 November 1976 (145451) Rumina 2005 RM 43 Rumīna r uː ˈ m aɪ n ə SDOTNO 2025 May 05 (JD 2460800.5) 1 35.147 AU Tm on 149.67 AU Tm on on 92.41 AU Tm on 8.226° 318.672° 84.629° 28.6976° 0.6197 888.36 yr (324475 19 d) 0 4.52 0.014.584.8 644 km ≈ (derived from occultation; 455 and 460 km measured)524 96 103 km 20.4 0.15 g/cm3 >0.48 - 0.63 g/cm3 (assuming a Jacobi ellipsoid) V–R=0.33 0.02 (neutral)B0−V00.590B–R0.99 0.102 0.0011095 ms / day 6.71 h d on on9.00 h d on on 145451 Rumina (provisional designation 2005 RM 43) is a large trans-Neptunian object in the scattered disc region beyond the Kuiper belt. It was discovered on 9 September 2005, by American astronomers Andrew Becker, Andrew Puckett and Jeremy Kubica at the Apache Point Observatory in Sunspot, New Mexico. It measures approximately 600 kilometers in diameter, and has an albedo of ~0.102, with a grey colored surface. History Discovery thumb|upright|The 2.5-meter telescope at Apache Point Observatory in Sunspot that was used to discover Rumina back in 2005 Rumina was discovered by astronomers Andrew Becker, Andrew Puckett and Jeremy Kubica on 9 September 2005, during observations for the Sloan Digital Sky Survey. The discovery observations were made using the 2.5-meter telescope at Apache Point Observatory in Sunspot, New Mexico. The discoverers further observed Rumina until November 2005 and found the object in precovery observations from dates as early as October 1999. The discovery of Rumina was announced by the Minor Planet Center on 23 July 2006. Since then, Rumina has been found in even earlier precovery observations dating back to November 1976. Rumina has been observed 548 times, the orbit is well determined with an uncertainty parameter of 1. Naming and numbering The object is named after Rumīna, a Roman goddess who protected nursing mothers.7 The naming of this object was announced by the International Astronomical Union's Working Group for Small Body Nomenclature on 1 September 2025.24 Before Rumina was officially named, it was known by its provisional designation 2005 RM 43, which indicates the year and half-month of the object's discovery date. Rumina's minor planet catalog number of 145451 was given by the Minor Planet Center on 5 December 2006. The Kuiper belt objects 145452 Ritona and (145453) 2005 RR 43 directly come after Rumina's number in the minor planet catalog. Orbit and classification Orbital characteristics Rumina orbits the Sun at a distance of 35.1–149.7 astronomical units (AU) with a semi-major axis or average orbital distance of 92.4 AU once every 888 years (for reference, Neptune's orbit is at 30 AU). Its orbit has a relatively high eccentricity of 0.62 and an inclination of 28.7° with respect to the ecliptic. Classification Rumina belongs to the scattered disc, which is a population of TNOs that have distant, inclined, and eccentric orbits that come close to Neptune at perihelion. The scattered disc population, which includes the dwarf planets Eris and Gonggong, are strongly influenced by Neptune's gravitational perturbations and consequently experience gravitational scattering.52 Both the Minor Planet Center (MPC) and Johnston's archive classify that Rumina is a scattered disc object. Physical characteristics Size In 2018, two stellar occultations by Rumina were observed on 3 February and 24 December. The February occultation yielded a single chord length of 456 km mi. Observations of the December occultation yielded two positive chords, which together suggest an approximate diameter of 644 km mi. The object rotates on its axis once every 6.71 hours. Density, shape, and rotation Based on its size of 456 and 644 km, it belongs to the proposed class of "mid-sized" TNOs between 400 and 1000 km mi in diameter, which are believed to represent the transition between small, low-density TNOs and large, high-density dwarf planets.1 Planetary scientists have hypothesized that mid-sized TNOs should have highly porous and unheated interiors, because TNOs in this size range (namely Uni and Gǃkúnǁʼhòmdímà) have been found to have low densities around 1 g/cm3. Johnston's archive estimate a density of >0.56 g/cm3 for Rumina. The density and shape of Rumina have been calculated by studying its rotational light curve. Photometric observations show that Rumina has a synodic rotational period of 9.00 0.06 h and a light curve amplitude of 0.12 0.05 mag. This light variation indicates a primary axis ratio lower limit of 1.12 0.05. Based on these rotational mechanics, the absolute minimum density required to keep the object from breaking apart due to centrifugal forces is 0.15 g/cm3. If Rumina is assumed to be a rotationally stable Jacobi ellipsoid in hydrostatic equilibrium, its bulk density is modeled to be within the range of 0.48 – 0.63 g/cm3, which is probably too low to be solid. Surface and spectra April 2026 Rumina has an absolute magnitude of 4.52 0.01. The surface of Rumina is dark grey with a low albedo of 0.102 and a V–R color index of 0.33 0.02, which means that it has a neutral color. See also List of trans-Neptunian objects List of minor planets: 145001–146000 List of possible dwarf planets References 2025-01-20 last obs JPL Small-Body Database Browser: 145451 Rumina (2005 RM43) https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=145451 August 19, 2025 List of Known Trans-Neptunian Objects Johnston's Archive Wm. Robert Johnston http://www.johnstonsarchive.net/astro/tnoslist.html 2 February 2019 https://web.archive.org/web/20190202194759/http://www.johnstonsarchive.net/astro/tnoslist.html 2 February 2019 (145451) Rumina = 2005 RM43 Minor Planet Center https://minorplanetcenter.net/db_search/show_object?utf8=%E2%9C%93&object_id=145451 2 February 2019 New- And Old-Style Minor Planet Designations https://www.minorplanetcenter.net/iau/info/DesDoc.html Minor Planet Center 2025-09-01 A. C. Becker A. W. Puckett J. Kubika G. V. Williams Gareth V. Williams MPEC 2006-O24 : 2005 RM43 https://www.minorplanetcenter.net/mpec/K06/K06O24.html Minor Planet Electronic Circular Minor Planet Center 2006-07-23 2006-O25 2025-09-01 2006MPEC....O...24B M.P.C. 58206 https://minorplanetcenter.net/iau/ECS/MPCArchive/2006/MPC_20061205.pdf#page=160 Minor Planet Circulars Minor Planet Center 58206 160 2006-12-05 2025-09-01 W. M. Grundy K. S. Noll M. W. Buie S. D. Benecchi D. Ragozzine H. G. Roe The Mutual Orbit, Mass, and Density of Transneptunian Binary Gǃkúnǁʼhòmdímà ((229762) 2007 UK 126) http://www2.lowell.edu/users/grundy/abstracts/preprints/2019.G-G.pdf Icarus December 2019 334 30–38 10.1016/j.icarus.2018.12.037 2019Icar..334...30G 126574999 2019-04-07 2026-03-30 https://web.archive.org/web/20190407045339/http://www2.lowell.edu/~grundy/abstracts/preprints/2019.G-G.pdf dead Scott Sheppard Yanga Fernandez Arielle Moullet The Albedos, Sizes, Colors and Satellites of Dwarf Planets Compared with Newly Measured Dwarf Planet 2013 FY27 The Astronomical Journal 156 6 270 6 September 2018 1809.02184 10.3847/1538-3881/aae92a 2018AJ....156..270S 119522310 free (145451) 2005RM43 – Observation prediction AstDyS Department of Mathematics, University of Pisa https://newton.spacedys.com/astdys/index.php?n=145451&pc=1.1.4.1&oc=500&y0=2019&m0=2&d0=2&h0=00&mi0=00&s=3.0 2 February 2019 The Youthful Appearance of the 2003 EL61 Collisional Family David L. Rabinowitz Bradley E. Schaefer Martha W. Schaefer Suzanne W. Tourtellotte 2008 0804.2864 10.1088/0004-6256/136/4/1502 136 The Astronomical Journal 4 1502–1509 2008AJ....136.1502R 117167835 How many dwarf planets are there in the outer solar system? (updates daily) California Institute of Technology Michael E. Brown Michael E. Brown http://web.gps.caltech.edu/~mbrown/dps.html 2 February 2019 https://web.archive.org/web/20190202195528/http://web.gps.caltech.edu/~mbrown/dps.html 2 February 2019 TNOs are Cool! A Survey of the transneptunian Region XV. Physical characteristics of 23 resonant transneptunian and scattered disk objects etal A. Farkas-Takács Cs. Kiss E. Vilenius G. Marton T. G. Müller M. Mommert Astronomy & Astrophysics 2002.12712 28 February 2020 A23 638 10.1051/0004-6361/201936183 free 2020A&A...638A..23F 216193564 TNO Results https://lesia.obspm.fr/lucky-star/results.php ERC Lucky Star Project Laboratoire d'Etudes Spatiales et d'Instrumentation en Astrophysique (LESIA) 13 July 2020 Donald K. Yeomans https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%278%27&TABLE_TYPE=%27ELEMENTS%27&START_TIME=%272000-01-01%27&STOP_TIME=%272000-01-02%27&STEP_SIZE=%27200%20years%27&CENTER=%27@0%27&OUT_UNITS=%27AU-D%27 HORIZONS Web-Interface for Neptune Barycenter (Major Body=8) JPL Horizons On-Line Ephemeris System 18 July 2014 7 September 2021 https://web.archive.org/web/20210907055935/https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%278%27&TABLE_TYPE=%27ELEMENTS%27&START_TIME=%272000-01-01%27&STOP_TIME=%272000-01-02%27&STEP_SIZE=%27200%20years%27&CENTER=%27%400%27&OUT_UNITS=%27AU-D%27 live —Select "Ephemeris Type: Orbital Elements", "Time Span: 2000-01-01 12:00 to 2000-01-02". ("Target Body: Neptune Barycenter" and "Center: Solar System Barycenter (@0)".) Occultation by 2005 RM43 in 03 02 2018 https://lesia.obspm.fr/lucky-star/campaigns/results/occulting_2005_rm43_03_02_2018S.pdf ERC Lucky Star Project Laboratoire d'Etudes Spatiales et d'Instrumentation en Astrophysique (LESIA) 3 February 2018 13 July 2020 Occultation by 2005 RM43 in 23 DEC 2018 https://lesia.obspm.fr/lucky-star/campaigns/results/2005RM43_24_12_2018_prelim2.pdf ERC Lucky Star Project Laboratoire d'Etudes Spatiales et d'Instrumentation en Astrophysique (LESIA) 24 December 2018 13 July 2020 Brett Gladman Brian G. Marsden Christa VanLaerhoven Nomenclature in the Outer Solar System https://www.lpi.usra.edu/books/ssbn2008/7002.pdf The Solar System Beyond Neptune University of Arizona Press 2008 43–57 9780816527557 astro-ph/0702538 2008ssbn.book...43G 14469199 dead https://web.archive.org/web/20230801104434/https://www.lpi.usra.edu/books/ssbn2008/7002.pdf 1 August 2023 List Of Centaurs and Scattered-Disk Objects https://www.minorplanetcenter.net/iau/lists/t_centaurs.html Minor Planet Center International Astronomical Union 17 December 2021 https://www.wgsbn-iau.org/files/Bulletins/V005/WGSBNBull_V005_020.pdf#page=7 7 Rumina is a minor Roman goddess who was invoked as a protector of nursing mothers. International Astronomical Union WGSBN Bulletin 5 20 (145451) Rumina = 2005 RM43 Perna D. Dotto E. Barucci M. A. Rossi A. Fornasier S. de Bergh C. 2009 Rotations and densities of trans-Neptunian objects (Research Note) Astronomy & Astrophysics 508 1 451–455 10.1051/0004-6361/200911970 free https://www.aanda.org/articles/aa/pdf/2009/46/aa11970-09.pdf External links (145451) 2005 RM43 Precovery Images 145452 145451 145451 145452 Ritona Category:Scattered disc and detached objects Rumina Rumina Rumina Category:Objects observed by stellar occultation 20050909 Rumina Category:Minor planets named after their provisional designation Rumina Category:Long stubs with short prose