(2241) Alcafa ( Latin Alcathous , ancient Greek Ἀλκάθοος ) is a Trojan asteroid of Jupiter , moving at L 5 , Lagrange, 60 ° behind the planet, which belongs to the spectral class D. The asteroid was discovered on November 22, 1979 by the American astronomer Charles Koval in the Palomar Observatory and named after Alcafoi , one of the Trojan leaders in Homer's Iliad [2] [3] .
- The orbit of the asteroid Alcapha and its position in the solar system
| (2241) Alcapha | |
|---|---|
| Asteroid | |
| Opening | |
| Discoverer | Charles Koval |
| Detection point | Palomar |
| Date of discovery | November 22, 1979 |
| Eponym | Alcapha |
| Alternative designations | 1979 WM ; 1950 NC; 1968 WF |
| Category | Jupiter's Trojans ( L 5 ) |
| Orbital characteristics | |
| The era of December 9, 2014 JD 2457000.5 | |
| Eccentricity ( e ) | 0.0664211 |
| Semi-axis ( a ) | 776.385 million km (5.1898127 a. E.) |
| Perihelion ( q ) | 724.817 million km (4.8450996 a. E.) |
| Afhelia ( Q ) | 827.953 million km (5.5345258 a. E.) |
| Period of circulation ( P ) | 4,318,431 days (11,823 g ) |
| Average orbital speed | 13.06 km / s |
| Inclination ( i ) | 16.61494 ° |
| Ascending node longitude (Ω) | 267.98882 ° |
| Perihelion Argument (ω) | 290.71886 ° |
| Mean Anomaly ( M ) | 214.79491 ° |
| Physical characteristics [1] | |
| Diameter | 114.63 km |
| Rotation period | 7,695 h |
| Spectral class | D |
| Apparent magnitude | 16.35 m (current) |
| Absolute magnitude | 8.64 m |
| Albedo | 0.0471 |
| Current distance from the Sun | 4,846 a. e. |
| Current distance from Earth | 5.321 a. e. |
Photometric observations made in the early 1990s [1] [4] (and later in 2011-2015 [5] [6] [7] [8] ), allowed us to obtain light curves of this body, from which it followed that the rotation of the asteroid around its axis is 7.687 ± 0.005 hours, with a change in brightness as it rotates 0.23 ± 0.01 m .
According to the results of measurements of infrared space telescopes IRAS and Wide-Field Infrared Survey Explorer , as well as the Japanese satellite Akari , the asteroid has a very low albedo value, according to different estimates from 0.044 to 0.048 [9] [10] [11] .
See also
- List of asteroids ( 2201–2300 )
- Small Planet Classifications
- List of Trojan Asteroids ("Greeks")
- List of Trojan Asteroids (Trojans)
Notes
- ↑ 1 2 Stefano Mottola1, Mario Di Martino, Anders Erikson, Maria Gonano-Beurer, Albino Carbognani, Uri Carsenty, Gerhard Hahn, Hans-Josef Schober, Felix Lahulla, Marco Delbò, and Claes-Ingvar Lagerkvist. ROTATIONAL PROPERTIES OF JUPITER TROJANS. I. LIGHT CURVES OF 80 OBJECTS (eng.) . The American Astronomical Society . The Astronomical Journal (May 2011). The appeal date is December 30, 2014.
- ↑ Schmadel, Lutz D. Dictionary of Minor Planet Names . - Fifth Revised and Enlarged Edition. - B. , Heidelberg, N. Y .: Springer, 2003. - P. 182. - ISBN 3-540-00238-3 .
- Made Schmadel, Lutz D. Dictionary of Minor Planet Names - (2241) Alcathous . - Springer Berlin Heidelberg, 2003. - P. 182. - ISBN 978-3-540-29925-7 .
- ↑ de Sanctis, MC; Barucci, MA; Angeli, CA; Fulchignoni, M .; Burchi, R .; Angelini, P. Photoelectric and CCD observations of 10 asteroids (Eng.) // Planetary and Space Science . - Elsevier , 1994. - October. - p . 859-864 . - ISSN 0032-0633 . - DOI : 10.1016 / 0032-0633 (94) 90066-3 . - .
- ↑ Stephens, Robert D .; Coley, Daniel R .; French, Linda M. Dispatches from the Trojan Camp - Jovian Trojan L5 Asteroids Observed from CS3: 2014 October - 2015 January (Eng.) // Bulletin of the Minor Planets: journal. - Section of the Lunar and Planetary Observers, 2015. - July ( vol. 42 , no. 3 ). - P. 216-224 . - ISSN 1052-8091 . - .
- ↑ Mottola, Stefano; Di Martino, Mario; Erikson, Anders; Gonano-Beurer, Maria; Carbognani, Albino; Carsenty, Uri; Hahn, Gerhard; Schober, Hans-Josef; Lahulla, Felix; Delbò, Marco; Lagerkvist, Claes-Ingvar. Rotational Properties of Jupiter Trojans. I. Light Curves of 80 Objects (Eng.) // The Astronomical Journal : journal. - IOP Publishing , 2011. - May ( vol. 141 , no. 5 ). - P. 32 . - DOI : 10.1088 / 0004-6256 / 141/5/170 . - .
- ↑ French, Linda M .; Stephens, Robert D .; Lederer, Susan M .; Coley, Daniel R .; Rohl, Derrick A. Trojan Asteroids (Eng.) // Bulletin of the Minor Planets: journal. - Section of the Lunar and Planetary Observers, 2011. - April ( vol. 38 , no. 2 ). - P. 116-120 . - ISSN 1052-8091 . - .
- ↑ Stephens, Robert D .; French, Linda M .; Davitt, Chelsea; Coley, Daniel R. At the Scaean Gates: Observations Jovian Trojan Asteroids, July- December 2013 (Eng.) // Bulletin of the Minor Planets: journal. - Section of the Lunar and Planetary Observers, 2014. - April ( vol. 41 , no. 2 ). - P. 95-100 . - ISSN 1052-8091 . - .
- ↑ Tedesco, EF; Noah, PV; Noah, M .; Price, SD IRAS Minor Planet Survey V6.0 (Eng.) // NASA Planetary Data System. - 2004. - October. -
- ↑ Usui, Fumihiko; Kuroda, Daisuke; Müller, Thomas G .; Hasegawa, Sunao; Ishiguro, Masateru; Ootsubo, Takafumi; Ishihara, Daisuke; Kataza, Hirokazu; Takita, Satoshi; Oyabu, Shinki; Ueno, Munetaka; Matsuhara, Hideo; Onaka, Takashi. Asteroid Catalog Using Akari: AKARI / IRC Mid-Infrared Asteroid Survey (Eng.) // Publications of the Astronomical Society of Japan : journal. - Astronomical Society of Japan, 2011. - October ( vol. 63 , no. 5 ). - P. 1117-1138 . - DOI : 10.1093 / pasj / 63.5.1117 . - .
- ↑ Mainzer, A .; Grav, T .; Masiero, J .; Hand, E .; Bauer, J .; Tholen, D .; McMillan, RS; Spahr, T .; Cutri, RM; Wright, E .; Watkins, J .; Mo, W .; Maleszewski, C. NEOWISE Studies of the Classified Asteroids: Preliminary Results (Eng.) // The Astrophysical Journal : journal. - IOP Publishing , 2011. - November ( vol. 741 , no. 2 ). - P. 25 . - DOI : 10.1088 / 0004-637X / 741/2/90 . - . - arXiv : 1109.6407 .