13 Egeria

Main-belt asteroid Egeria (disambiguation)Egeria September 2025 yes #D6D6D6 13 Egeria 13 Egeria VLT (2021), deconvolved.pdf A deconvolved image of 13 Egeria by VLT/SPHERE 24px|class=skin-invert|alt=13 Egeria symbol|𜻆 (historical)24px|class=skin-invert|alt=Original buckler symbol (variant) Annibale de Gasparis Naples Obs. 2 November 1850 ᵻ ˈ dʒ ɪər i əNoah Webster (1884) A Practical Dictionary of the English Language Egerian Egeria (13) Egeria 1850 VA Main belt 17.0 October 2024 (JD 2460600.5) 2.57774 AU 2.35759 AU 2.79788 AU 0.085403 4.14 yr (1511.7 d) 16.532° 43.208° 79.222° 305.547° 18.56 km/s 202 3 km207.6 ± 8.3 km (IRAS) 214.8 km × 192 km238 x 199 x 182 km (± 12 x 11 x 10 km) 0.24Flattening derived from the maximum aspect ratio (c/a): , where (c/a) = 0.76 0.06. 7.24 0.34 18 kgCalculated from its standard gravitational parameter GM = 0.483 0.023 km3 s2. 1.68 0.11 g/cm3Assuming a diameter of 202 ± 3 km. ≈0.0580 m/s2 ≈0.1098 km/s 7.045 h7.046664 0.000003 h 59° G-type asteroid 9.71 to 12.46apmag 9.71 (2061-Nov-06) to 12.46 (1990-Mar-12) JPL Horizons daily output for 1950 to 2099 6.916.74 31 5 deg 38 5 deg 0.0870.049 ± 0.0280.085 ± 0.007http://www.psi.edu/pds/archive/astdata04/simps04/diamalb.tab https://archive.today/20060523221500/http://www.psi.edu/pds/archive/astdata04/simps04/diamalb.tab dead 2006-05-23 Asteroid Data Archive 2008-11-03 Planetary Science Institute ~174 K 0.23815 ms / day 63566 days (174.03 yr) 0 1.43636 AU 2.35842 AU 3.363 13 Egeria is a large main-belt G-type asteroid. It was discovered by Annibale de Gasparis on 2 November 1850. Egeria was named by Urbain Le Verrier, whose computations led to the discovery of Neptune, after the mythological nymph Egeria of Aricia, Italy, the wife of Numa Pompilius, second king of Rome. History Egeria was discovered on the evening of 2 November 1850 by Italian astronomer Annibale de Gasparis at the Astronomical Observatory of Capodimonte.128 Whereas de Gasparis's previous two discoveries—10 Hygiea and 11 Parthenope—were identified by comparison with the Berlin Academy star charts, Egeria was identified using his own ecliptic charts intended for finding new celestial objects.119128 Egeria's discovery was announced in December 1850 by astronomer Benjamin A. Gould through The Astronomical Journal. Following the discovery, de Gasparis delegated the naming rights of the asteroid to Urbain Le Verrier. Le Verrier chose to name the asteroid after Egeria, a mythological nymph and councillor of Numa Pompilius.128 Upon its discovery, both de Gasparis and Gould labelled Egeria as a new planet. However, by the mid-1800s, the classification and terminology of the asteroids were quickly evolving. Soon after Egeria's discovery, other astronomers described it as an "asteroid" or a "minor planet".25 Throughout the latter half of the 19th century, the terms "asteroid" and "minor planet" became favored, although some publications continued to label Egeria and other asteroids as planets.42 In 1851, de Gasparis announced his chosen symbol for Egeria—that of a buckler. However, Gould had apparently not seen the announcement, and in an 1852 table of asteroid symbols he left Egeria's blank.8 No mention of a star was made, though in 1852 John Russell Hind included one in his drawn symbol for Egeria: 15px|class=skin-invert|alt=13 Egeria symbol (U+1CEC6 𜻆 in Unicode 17.0). The symbol is sometimes depicted with a round form (15px|class=skin-invert|alt=Variant 13 Egeria symbol),8 though only Hind's form was encoded. Miscellaneous Symbols Supplement 2025 unicode.org The Unicode Consortium https://www.unicode.org/charts/PDF/U1CEC0.pdf September 9, 2025 live As the number of asteroids assigned a symbol grew in number through the mid-1800s, the practicality of assigning each a unique astronomical symbol was questioned. In 1851, astronomer Johann Franz Encke proposed an alternative system of a number—denoting the object's order of discovery—inscribed in a circle. For Egeria, this would be ⑬. This system was quickly adopted by astronomers, though eventually astronomers switched from an inscribed circle to parentheses and eventually a bare number—hence (13) Egeria or 13 Egeria in modern notation. Orbit Egeria orbits the Sun at an average distance—its semi-major axis—of 2.58 astronomical units (AU), placing it within the main asteroid belt and near the 3:1 mean-motion resonance with Jupiter.323 Along its orbit, its distance from the Sun varies between 2.36 AU at perihelion to 2.80 AU at aphelion due to its orbital eccentricity of 0.09. Its orbit is inclined by 16.5° with respect to the ecliptic, and it takes 4.14 years to complete one orbit. Egeria is classified as a background asteroid, as it does not belong to an asteroid family. Physical properties thumb|left|200px|OCCULT4 visualization of Egeria's 2008 occultation event Egeria occulted a star on 8 January 1992. Its disc was determined to be quite circular (217×196 km). On 22 January 2008, it occulted another star, and this occultation was timed by several observers in New Mexico and Arizona, coordinated by the IOTA Asteroid Occultation Program. The result showed that Egeria presented an approximately circular profile to Earth of 214.8×192 km, well in agreement with the 1992 occultation.April 2014 It has also been studied by radar. In 1988 a search for satellites or dust orbiting this asteroid was performed using the UH88 telescope at the Mauna Kea Observatories, but the effort came up empty. Spectral analysis of Egeria shows it to be unusually high in water content, 10.5–11.5% water by mass. thumb|A three-dimensional model of 13 Egeria based on its light curve See also Former classification of planets Notes References (13) Egeria = 1850 VA https://www.minorplanetcenter.net/db_search/show_object?utf8=%E2%9C%93&object_id=13 Minor Planet Center 8 September 2025 2024-12-04 last obs JPL Small-Body Database Browser: 13 Egeria http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=13 21 December 2024 (13) Egeria – Proper Elements https://newton.spacedys.com/astdys/index.php?pc=1.1.6&n=13 Asteroids Dynamic Site 24 January 2026 Vernazza P. et al. VLT/SPHERE imaging survey of the largest main-belt asteroids: Final results and synthesis October 2021 Astronomy and Astrophysics 654 A56 A56 10.1051/0004-6361/202141781 free 2021A&A...654A..56V 10045/118969 free Gavin Jared Bala Kirk Miller Unicode request for historical asteroid symbols https://www.unicode.org/L2/L2023/23207-historical-asteroids.pdf 18 September 2023 unicode.org Unicode 26 September 2023 The Solar System: Descriptive Treatise Upon the Sun, Moon, and Planets, Including an Account of All the Recent Discoveries en Chapter VIII. The Minor or Ultra-Zodiacal Planets. https://archive.org/details/solarsystemdescr00hind/page/126/mode/2up John Russell Hind John Russell Hind 1852 126 G. P. Putnam's Sons New York, United States de Gasparis Annibale Account of discovery of Egeria, November 2, 1850 November 1850 Monthly Notices of the Royal Astronomical Society 11 1 10.1093/mnras/11.1.1 free 1850MNRAS..11....1D Gould B. A. New planet (13) Egeria 6 December 1850 Astronomical Journal 1 20 158 10.1086/100108 1850AJ......1..158G B. A. Gould On the symbolic notation of the asteroids https://articles.adsabs.harvard.edu/pdf/1852AJ......2...80G The Astronomical Journal January 1852 2 80 10.1086/100212 1852AJ......2...80G Airy G. B. Address on presenting the medal to Dr. A. de Gasparis February 1851 Monthly Notices of the Royal Astronomical Society 11 116–120 10.1093/mnras/11.4.116 free 1851MNRAS..11..116A Hind John Russel An Astronomical Vocabulary: Being an Explanation of All Terms in Use Amongst Astronomers at the Present Day 1852 John W. Parker and Son 978-1120148056 J. L. Hilton When did asteroids become minor planets? http://aa.usno.navy.mil/faq/docs/minorplanets.php U.S. Naval Observatory 16 November 2007 27 March 2025 dead https://web.archive.org/web/20070921162818/http://aa.usno.navy.mil/faq/docs/minorplanets.php 21 September 2007 Airy George Biddell Horizontal and Vertical Diameters and Right Ascensions and North Polar Distances of the Sun, Moon and Planets, Deduced from the Observations, and Compared with the Nautical Almanac 1869 Greenwich Observations in Astronomy, Magnetism and Meteorology Made at the Royal Observatory 2 29 D31–D63 1869GOAMM..29D..31A Rivkin A. S. Davies J. K. Calculated water concentrations on C-class asteroids Lunar and Planetary Science 2002 XXXIII 1414 2002LPI....33.1414R https://www.lpi.usra.edu/meetings/lpsc2002/pdf/1414.pdf http://www.asteroidoccultation.com/observations/Results/Data2008/20080122_EgeriaProfile.png IOTA Asteroid Occultation Results for 2008 Timerson Brad 2010-01-19 https://web.archive.org/web/20140416210320/http://www.asteroidoccultation.com/observations/Results/Data2008/20080122_EgeriaProfile.png 2014-04-16 dead Schmadel Lutz D. Dictionary of minor planet names 1 5th 2003 Springer-Verlag Berlin Heidelberg New York 3-540-00238-3 16 http://www.lpi.usra.edu/meetings/LPSC98/pdf/1310.pdf High-resolution 2.5–3.5 M Observations of C-, B- and G-class asteroids. Rivkin A. S. J. K. Davies S. L. Ellison L. A. Lebofsky 2008-04-20 Radar-Detected Asteroids and Comets NASA/JPL Asteroid Radar Research http://echo.jpl.nasa.gov/asteroids/ 2011-10-30 Gradie J. Flynn L. A Search for Satellites and Dust Belts Around Asteroids: Negative Results Abstracts of the Lunar and Planetary Science Conference 19 405–406 March 1988 1988LPI....19..405G . Bottke William F., Jr. Rubincam David P. Burns Joseph A. Dynamical Evolution of Main Belt Meteoroids: Numerical Simulations Incorporating Planetary Perturbations and Yarkovsky Thermal Forces June 2000 Icarus 145 2 303–331 10.1006/icar.2000.6361 2000Icar..145..301B Fuentes-Muñoz Oscar Farnocchia Davide Giorgini Jon D. Park Ryan S. 2025-12-01 Asteroid Mass Estimation by Mutual Perturbations During Close Encounters After Gaia Focused Product Release The Astronomical Journal 170 6 353 10.3847/1538-3881/ae0cc9 0004-6256 free 2025AJ....170..353F 283347135 External links Elements and Ephemeris for (13) Egeria Minor Planet Center http://scully.cfa.harvard.edu/cgi-bin/returnprepeph.cgi?d=b2011&o=00013 dead https://web.archive.org/web/20160304084942/http://scully.cfa.harvard.edu/cgi-bin/returnprepeph.cgi?d=b2011&o=00013 2016-03-04 2011-05-26 (displays Elong from Sun and V mag for 2011) 13 12 Victoria 13 14 Irene 000013 Category:Discoveries by Annibale de Gasparis Category:Named minor planets 000013 000013 000013 18501102