Summary
2204 Lyyli (prov. designation: 1943 EQ) is a dark asteroid and very eccentric Mars-crosser from the middle region of the asteroid belt, approximately 25 kilometers (16 miles) in diameter. It was discovered on 3 March 1943 by Finnish astronomer Yrjö Väisälä at Turku Observatory in Southwest Finland.[3]
 Shape model of Lyyli from its lightcurve | |
| Discovery [1] | |
|---|---|
| Discovered by | Y. Väisälä |
| Discovery site | Turku Obs. |
| Discovery date | 3 March 1943 |
| Designations | |
| (2204) Lyyli | |
Named after | Lyyli Heinänen (Esperantist)[2] |
| 1943 EQ · 1968 DN | |
| Mars-crosser [1][3] | |
| Orbital characteristics [1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 73.75 yr (26,937 days) |
| Aphelion | 3.6435 AU |
| Perihelion | 1.5354 AU |
| 2.5894 AU | |
| Eccentricity | 0.4071 |
| 4.17 yr (1,522 days) | |
| 350.25° | |
| Inclination | 20.561° |
| 160.45° | |
| 283.25° | |
| Earth MOID | 0.6872 AU |
| Mars MOID | 0.2547 AU |
| Physical characteristics | |
Mean diameter | 25.16±2.4 km (IRAS:11)[4] 25.27 km (derived)[5] 27.12±1.31 km[6] |
| 9.51±0.01 h[7] 10 h[8] 11.063±0.001 h[9] 11.09±0.01 h[10] | |
| 0.020±0.002[6] 0.0232±0.005 (IRAS:11)[4] 0.050±0.006[11] 0.0537 (derived)[5] | |
| SMASS = X [1] · P [11] · X [5] | |
| 11.61±0.44[12] · 11.78[5] · 12.1[1] · 12.70[4][6] | |
Orbit and classification edit
Lyyli orbits the Sun in the central main-belt at a distance of 1.5–3.6 AU once every 4 years and 2 months (1,522 days). Its orbit has an eccentricity of 0.41 and an inclination of 21° with respect to the ecliptic.[1]
Naming edit
This minor planet was named in honour of Lyyli Heinänen (1903–1988), née Hartonen, a Finnish female Esperantist, professor of mathematics, amateur astronomer and former assistant of the discoverer.[2] The official naming citation was published by the Minor Planet Center on 26 May 1983 (M.P.C. 7944).[13]
Physical characteristics edit
Lyyli is an X-type asteroid in the SMASS classification.[1] It has also been characterized as a P-type asteroid by NASA's NEOWISE mission.[11]
It has a rotation period of 11 hours[9] and a very low albedo between 0.02 and 0.05, according to the surveys carried out by IRAS, Akari, and WISE/NEOWISE.[4][6][11] Other large Mars crossing minor planets include 132 Aethra and 323 Brucia, with diameters of 43 and 36 kilometers, respectively.
References edit
- ^ a b c d e f g "JPL Small-Body Database Browser: 2204 Lyyli (1943 EQ)" (2016-12-01 last obs.). Jet Propulsion Laboratory. Retrieved 12 June 2017.
- ^ a b Schmadel, Lutz D. (2007). "(2204) Lyyli". Dictionary of Minor Planet Names. Springer Berlin Heidelberg. p. 179. doi:10.1007/978-3-540-29925-7_2205. ISBN 978-3-540-00238-3.
- ^ a b "2204 Lyyli (1943 EQ)". Minor Planet Center. Retrieved 7 December 2016.
- ^ a b c d Tedesco, E. F.; Noah, P. V.; Noah, M.; Price, S. D. (October 2004). "IRAS Minor Planet Survey V6.0". NASA Planetary Data System: IRAS-A-FPA-3-RDR-IMPS-V6.0. Bibcode:2004PDSS...12.....T. Retrieved 22 October 2019.
- ^ a b c d "LCDB Data for (2204) Lyyli". Asteroid Lightcurve Database (LCDB). Retrieved 7 December 2016.
- ^ a b c d 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)
- ^ Gil-Hutton, R.; Cañ; ada, M. (April 2003). "Photometry of Fourteen Main Belt Asteroids". Revista Mexicana de Astronomía y Astrofísica. 39: 69–76. Bibcode:2003RMxAA..39...69G. Retrieved 7 December 2016.
- ^ Mohamed, R. A.; Krugly, Yu. N.; Velichko, F. P. (April 1994). "Photometry of two Mars-crossing asteroids 2078 Nanking and 2204 Lyyli". Planetary and Space Science. 42 (4): 341–343. Bibcode:1994P&SS...42..341M. doi:10.1016/0032-0633(94)90107-4. Retrieved 7 December 2016.
- ^ a b Warner, Brian D. (October 2010). "Asteroid Lightcurve Analysis at the Palmer Divide Observatory: 2010 March - June" (PDF). Minor Planet Bulletin. 37 (4): 161–165. Bibcode:2010MPBu...37..161W. ISSN 1052-8091. Retrieved 18 March 2020.
- ^ Warner, Brian D. (January 2016). "Asteroid Lightcurve Analysis at CS3-Palmer Divide Station: 2015 June-September" (PDF). Minor Planet Bulletin. 43 (1): 57–65. Bibcode:2016MPBu...43...57W. ISSN 1052-8091. Archived from the original (PDF) on 3 October 2020. Retrieved 18 March 2020.
- ^ a b c d Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; Bauer, J.; Tholen, D.; et al. (November 2011). "NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results". The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. Retrieved 2 May 2016.
- ^ Veres, Peter; Jedicke, Robert; Fitzsimmons, Alan; Denneau, Larry; Granvik, Mikael; Bolin, Bryce; et al. (November 2015). "Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 - Preliminary results". Icarus. 261: 34–47. arXiv:1506.00762. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. Retrieved 7 December 2016.
- ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 7 December 2016.
External links edit
- Lightcurve plot of 2204 Lyyli, Palmer Divide Observatory, B. D. Warner (2010)
- 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
- 2204 Lyyli at AstDyS-2, Asteroids—Dynamic Site
- Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
- 2204 Lyyli at the JPL Small-Body Database
