946 Poësia /poʊˈiːsiə/ is a Themis asteroid and slow rotator, approximately 39 kilometers (24 miles) in diameter, located in the outer regions of the asteroid belt. It was discovered by German astronomer Max Wolf at the Heidelberg-Königstuhl State Observatory on 11 February 1921 and given the provisional designations A921 CD and 1921 JC.[1] The F-type asteroid has a long rotation period of 108.5 hours. It was named after the goddess of poetry.[3]
| Discovery [1] | |
|---|---|
| Discovered by | M. F. Wolf |
| Discovery site | Heidelberg Obs. |
| Discovery date | 11 February 1921 |
| Designations | |
| (946) Poësia | |
| Pronunciation | /poʊˈiːsiə/[2] |
Named after | poetry (goddess of poetry)[3] |
| A921 CD · 1959 AA A911 KB · 1911 KB 1921 JC | |
| main-belt [1][4] · (outer) Themis [5][6] | |
| Orbital characteristics [4] | |
| Epoch 31 May 2020 (JD 2459000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 98.66 yr (36,034 d) |
| Aphelion | 3.5647 AU |
| Perihelion | 2.6709 AU |
| 3.1178 AU | |
| Eccentricity | 0.1433 |
| 5.51 yr (2,011 d) | |
| 30.119° | |
| 0° 10m 44.4s / day | |
| Inclination | 1.4312° |
| 69.661° | |
| 37.936° | |
| Physical characteristics | |
Mean diameter | |
| 108.5±0.5 h[10][11] | |
| 10.6[1][4] | |
Orbit and classification edit
Poësia is a core member of the Themis family (602), a very large family of carbonaceous asteroids, named after 24 Themis.[5][6][12]: 23 It orbits the Sun in the outer asteroid belt at a distance of 2.7–3.6 AU once every 5 years and 6 months (2,011 days; semi-major axis of 3.12 AU). Its orbit has an eccentricity of 0.14 and an inclination of 1° with respect to the ecliptic.[4] The body's observation arc begins at Heidelberg Observatory on 11 May 1921, or three months after its official discovery observation.[1]
Naming edit
This minor planet was named after the goddess of poetry. The name was proposed by Russian astronomer Nikolaj Komendantov (1895–1937), and the naming was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 91).[3]
Physical characteristics edit
In the Tholen classification, Poësia is an uncommon F-type asteroid, though with an unusual spectrum,[4] while in the Barucci taxonomy, it is a carbonaceous C0-type.[6] The overall spectral type for members of the Themistian family is that of a C-type.[12]: 23
Rotation period edit
In January 2009, a rotational lightcurve of Poësia was obtained from photometric observations by Robert Stephens at the Santana Observatory (646) and Goat Mountain Astronomical Research Station (G79) in California. Lightcurve analysis gave an exceptionally long rotation period of 108.5±0.5 hours with a brightness amplitude of 0.32±0.05 magnitude (U=2+).[11] A few weeks later, Gary A. Vander Haagen at Stonegate Observatory (H67) determined an ambiguous period of 73.5 or 102.9 hours with an amplitude of 0.24±0.05 magnitude (U=2),[13] while René Roy measured a tentative period of 48 hours (U=1).[14] With a best-rated period of 108.5 hours, Poësia is a slow rotator. While the slowest rotators have periods above 1000 hours, the vast majority of asteroids have periods between 2.2 and 20 hours.
Diameter and albedo edit
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), and the Infrared Astronomical Satellite IRAS, Poësia measures 36.210±0.149, 39.60±0.64 and 43.75±4.6 kilometers in diameter, and its surface has a corresponding albedo of 0.097±0.008, 0.079±0.003 and 0.0627±0.015, respectively.[7][8][9] The Collaborative Asteroid Lightcurve Link adopts the results from IRAS, that is, an albedo of 0.0627 and a diameter of 43.75 km based on an absolute magnitude of 9.8.[10]
Further published mean-diameters and albedos by the WISE team include 33.30±10.10 km, 35.84±11.06 km, 37.604±0.255 km and 38.990±0.248 km with albedos of 0.06±0.06, 0.06±0.04, 0.097±0.008 and 0.0789±0.0085, respectively.[6][10]
References edit
- ^ a b c d e "946 Poesia (A921 CD)". Minor Planet Center. Retrieved 15 February 2020.
- ^ "poesis, poiesis". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)
- ^ a b c Schmadel, Lutz D. (2007). "(946) Poësia". Dictionary of Minor Planet Names. Springer Berlin Heidelberg. p. 83. doi:10.1007/978-3-540-29925-7_947. ISBN 978-3-540-00238-3.
- ^ a b c d e f g h "JPL Small-Body Database Browser: 946 Poesia (A921 CD)" (2020-01-06 last obs.). Jet Propulsion Laboratory. Retrieved 15 February 2020.
- ^ a b "Asteroid 946 Poesia – Proper Elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 15 February 2020.
- ^ a b c d "Asteroid 946 Poesia". Small Bodies Data Ferret. Retrieved 15 February 2020.
- ^ a b c Masiero, Joseph R.; Grav, T.; Mainzer, A. K.; Nugent, C. R.; Bauer, J. M.; Stevenson, R.; et al. (August 2014). "Main-belt Asteroids with WISE/NEOWISE: Near-infrared Albedos". The Astrophysical Journal. 791 (2): 11. arXiv:1406.6645. Bibcode:2014ApJ...791..121M. doi:10.1088/0004-637X/791/2/121.
- ^ a b c Usui, Fumihiko; Kuroda, Daisuke; Müller, Thomas G.; Hasegawa, Sunao; Ishiguro, Masateru; Ootsubo, Takafumi; et al. (October 2011). "Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey". Publications of the Astronomical Society of Japan. 63 (5): 1117–1138. Bibcode:2011PASJ...63.1117U. doi:10.1093/pasj/63.5.1117. (online, AcuA catalog p. 153)
- ^ a b c Tedesco, E. F.; Noah, P. V.; Noah, M.; Price, S. D. (October 2004). "IRAS Minor Planet Survey V6.0". NASA Planetary Data System. 12: IRAS-A-FPA-3-RDR-IMPS-V6.0. Bibcode:2004PDSS...12.....T. Retrieved 14 February 2020.
- ^ a b c "LCDB Data for (946) Poësia". Asteroid Lightcurve Database (LCDB). Retrieved 15 February 2020.
- ^ a b Stephens, Robert D. (July 2009). "Asteroids Observed from GMARS and Santana Observatories: 2009 January – February" (PDF). The Minor Planet Bulletin. 36 (3): 125–126. Bibcode:2009MPBu...36..125S. Archived from the original (PDF) on 26 November 2021. Retrieved 15 February 2020.
- ^ a b Nesvorný, D.; Broz, M.; Carruba, V. (December 2014). "Identification and Dynamical Properties of Asteroid Families". Asteroids IV: 297–321. arXiv:1502.01628. Bibcode:2015aste.book..297N. doi:10.2458/azu_uapress_9780816532131-ch016.
- ^ Vander Haagen, Gary A. (October 2009). "Lightcurves and H-G Parameters for 901 Brunsia and 946 Poesia" (PDF). The Minor Planet Bulletin. 36 (4): 136–138. Bibcode:2009MPBu...36..136V.
- ^ Behrend, Raoul. "Asteroids and comets rotation curves – (946) Poësia". Geneva Observatory. Retrieved 15 February 2020.
External links edit
- Lightcurve Database Query (LCDB), at www.minorplanet.info
- Dictionary of Minor Planet Names, Google books
- Asteroids and comets rotation curves, CdR – Geneva Observatory, Raoul Behrend
- Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
- 946 Poësia at AstDyS-2, Asteroids—Dynamic Site
- 946 Poësia at the JPL Small-Body Database
