1009 Sirene

Mars-crossing asteroid October 2019 yes 1009 Sirene #FA8072 K. Reinmuth Heidelberg Obs. 31 October 1923 (1009) Sirene 1923 PE de ˈziːʁeːnə lang Siren (Σειρήν - Sīrēn) (Greek mythology) Mars-crosser 4 September 2017 (JD 2458000.5) 0 92.69 yr (33,854 days) 3.8207 AU 1.4259 AU 2.6233 AU 0.4564 4.25 yr (1,552 days) 11.512° 0.2320 ms / day 15.775° 229.46° 186.35° 0.4384 AU170.8 LD 5 km (est. at 0.20) 13.9 Sirene (minor planet designation: 1009 Sirene), provisional designation 1923 PE, is an eccentric asteroid and sizable Mars-crosser from the central regions of the asteroid belt, approximately 5 kilometers in diameter. It was discovered by German astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory on 31 October 1923. The asteroid was named after the Siren from Greek mythology. Orbit and classification Sirene is a Mars-crossing asteroid with a notably large semi-major axis is 2.62 AU, due to its high eccentricity of 0.46. It orbits the Sun in the central main-belt at a distance of 1.4–3.8 AU once every 4 years and 3 months (1,552 days). Its orbit has an inclination of 16° with respect to the ecliptic. The body's observation arc begins 9 days after its official discovery observation at Bergedorf Observatory in Hamburg. On 8 June 1949, Sirene passed 0.049 AU km mi on on from Mars. Aethra group and mass of Mars Sirene had been of great interest in 1930s. After its discovery, it was observed at Algiers, Bergedorf, Heidelberg, Milan, Vienna and Williams Bay in the United States, where it became too faint to be accurately observed. It was regarded as an excellent example of a member of the then called "Aethra group" – 132 Aethra was the first discovered Mars-crossing asteroid – highly appropriate to measure the exact mass of Mars on its next opposition near perihelion in 1937. However, after its last observation at Williams Bay in 1924, Sirene had only been observed once at Turku Observatory in 1940, and remained unobserved until the 1980s. Physical characteristics Rotation period As of 2017, no rotational lightcurve of Sirene has been obtained from photometric observations. The asteroid's rotation period, shape and poles remain unknown. Diameter and albedo Sirene has not been observed by any large-scale, space-based surveys such as IRAS, NEOWISE and Akari. Based on a generic magnitude-to-diameter conversion, Sirene measures 5 kilometers in diameter for an absolute magnitude of 13.9 and an assumed stony albedo of 0.20. For an assumed albedo of 0.10 and 0.05, its calculated diameter would increase to 7.1 and 10 kilometers, respectively. Naming This minor planet was named from Greek mythology after the Siren, who lured nearby sailors with their enchanting music and voices to shipwreck on the rocky coast of their island. The official naming citation was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 96). References 30em 2016-07-08 last obs. JPL Small-Body Database Browser: 1009 Sirene (1923 PE) https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2001009 Jet Propulsion Laboratory 5 September 2017 Dictionary of Minor Planet Names – (1009) Sirene Schmadel Lutz D. Springer Berlin Heidelberg 87 2007 978-3-540-00238-3 10.1007/978-3-540-29925-7_1010 (1009) Sirene 1009 Sirene (1923 PE) Minor Planet Center https://www.minorplanetcenter.net/db_search/show_object?object_id=1009 5 September 2017 Meister, H. J. November 1935 Definitive Bahn für 1009 Sirene Astronomische Nachrichten 257 15 233 1935AN....257..233M 10.1002/asna.19352571502 Asteroid Size Estimator CNEOS/JPL https://cneos.jpl.nasa.gov/tools/ast_size_est.html 5 September 2017 1009 5 September 2017 External links Asteroid Lightcurve Database (LCDB), query form (info https://web.archive.org/web/20171216050541/http://www.minorplanet.info/lightcurvedatabase.html 16 December 2017 ) Dictionary of Minor Planet Names, Google books Asteroids and comets rotation curves, CdR https://web.archive.org/web/20160729213840/http://obswww.unige.ch/~behrend/page_cou.html 29 July 2016 – Observatoire de Genève, Raoul Behrend Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center 1009 1008 La Paz 1009 1010 Marlene 001009 Category:Discoveries by Karl Wilhelm Reinmuth Category:Named minor planets 19231031 01009