Summary
464 Megaira (prov. designation: A901 AB or 1901 FV) is a dark and large background asteroid, approximately 77 kilometers (48 miles) in diameter, located in the central region of the asteroid belt. It was discovered by astronomer Max Wolf at the Heidelberg Observatory in southwest Germany on 9 January 1901.[1] The carbonaceous C-type asteroid (FX) has a rotation period of 12.9 hours. It was named after Megaera from Greek mythology.[3]
| Discovery [1] | |
|---|---|
| Discovered by | M. F. Wolf |
| Discovery site | Heidelberg Obs. |
| Discovery date | 9 January 1901 |
| Designations | |
| (464) Megaira | |
| Pronunciation | /mɪˈɡaɪərə/ (Megaira) /mɪˈdʒɪərə/ (Megaera)[2] |
Named after | Megaera (Greek mythology)[3] |
| A901 AB · 1929 AH A912 JB · A912 JC A916 FD · 1901 FV | |
| Orbital characteristics [4] | |
| Epoch 31 May 2020 (JD 2459000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 119.07 yr (43,489 d) |
| Aphelion | 3.3764 AU |
| Perihelion | 2.2248 AU |
| 2.8006 AU | |
| Eccentricity | 0.2056 |
| 4.69 yr (1,712 d) | |
| 253.43° | |
| 0° 12m 37.08s / day | |
| Inclination | 10.170° |
| 102.37° | |
| 258.19° | |
| Physical characteristics | |
Mean diameter | |
| 12.879±0.001 h[10] | |
| 9.7[1][4] | |
Orbit and classification edit
Megaira is a non-family asteroid of the main belt's background population when applying the hierarchical clustering method to its proper orbital elements.[5][6] It orbits the Sun in the central asteroid belt at a distance of 2.2–3.4 AU once every 4 years and 8 months (1,712 days; semi-major axis of 2.8 AU). Its orbit has an eccentricity of 0.21 and an inclination of 10° with respect to the ecliptic.[4] The body's observation arc begins at Heidelberg Observatory with its official discovery observation on 9 January 1901.[1]
Naming edit
This minor planet was named after Megaera, the avenging spirit from Greek mythology. She is one of the three Erinyes (Furies), who bring retribution on those guilty of sins. The naming was also mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 50).[3] It was the first numbered minor planet detected in the 20th century.[3]
Physical characteristics edit
In the Tholen classification-SMASS classification, Megaira is closest to a dark F-type asteroid, and somewhat similar to an X-type, though with an unusual (U) and noisy spectra (:).[4] In the Bus–Binzel SMASS classification it is a common carbonaceous C-type asteroid.
Rotation period edit
In March 2019, a rotational lightcurve of Megaira was obtained from photometric observations by Frederick Pilcher. Lightcurve analysis gave a well-defined rotation period of 12.879±0.001 hours with a brightness variation of 0.12±0.01 magnitude (U=3).[10] The result supersedes previously published period determinations.[11][12][13]
Diameter and albedo edit
According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Megaira measures between 55.09 and 85.50 kilometers in diameter and its surface has an albedo between 0.03 and 0.06.[6][7][8][9][14] The Collaborative Asteroid Lightcurve Link takes an albedo of 0.0469 from Petr Pravec's revised WISE data and calculates a diameter of 78.29 kilometers based on an absolute magnitude of 9.47.[14]
References edit
- ^ a b c d e "464 Megaira (A901 AB)". Minor Planet Center. Retrieved 11 March 2020.
- ^ "Megaera". Lexico UK English Dictionary. Oxford University Press. Archived from the original on 22 March 2020.
- ^ a b c d Schmadel, Lutz D. (2007). "(464) Megaira". Dictionary of Minor Planet Names. Springer Berlin Heidelberg. p. 52. doi:10.1007/978-3-540-29925-7_465. ISBN 978-3-540-00238-3.
- ^ a b c d e f g h "JPL Small-Body Database Browser: 464 Megaira (A901 AB)" (2020-02-03 last obs.). Jet Propulsion Laboratory. Retrieved 11 March 2020.
- ^ a b "Asteroid 464 Megaira – Proper Elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 11 March 2020.
- ^ a b c "Asteroid 464 Megaira". Small Bodies Data Ferret. Retrieved 11 March 2020.
- ^ 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 11 March 2020.
- ^ a b c Mainzer, A. K.; Bauer, J. M.; Cutri, R. M.; Grav, T.; Kramer, E. A.; Masiero, J. R.; et al. (June 2016). "NEOWISE Diameters and Albedos V1.0". NASA Planetary Data System. Bibcode:2016PDSS..247.....M. Retrieved 11 March 2020.
- ^ 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 Pilcher, Frederick (July 2019). "Rotation Period Determinations for 58 Concordia, 384 Burdigala, 464 Megaira, 488 Kreusa, and 491 Carina" (PDF). Minor Planet Bulletin. 46 (3): 360–363. Bibcode:2019MPBu...46..360P. ISSN 1052-8091.
- ^ Behrend, Raoul. "Asteroids and comets rotation curves – (464) Megaira". Geneva Observatory. Retrieved 11 March 2020.
- ^ Polakis, Tom (July 2019). "Lightcurves of Twelve Main-Belt Minor Planets" (PDF). Minor Planet Bulletin. 46 (3): 287–292. Bibcode:2019MPBu...46..287P. ISSN 1052-8091.
- ^ Waszczak, Adam; Chang, Chan-Kao; Ofek, Eran O.; Laher, Russ; Masci, Frank; Levitan, David; et al. (September 2015). "Asteroid Light Curves from the Palomar Transient Factory Survey: Rotation Periods and Phase Functions from Sparse Photometry". The Astronomical Journal. 150 (3): 35. arXiv:1504.04041. Bibcode:2015AJ....150...75W. doi:10.1088/0004-6256/150/3/75.
- ^ a b "LCDB Data for (464) Megaira". Asteroid Lightcurve Database (LCDB). Retrieved 11 March 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
- 464 Megaira at AstDyS-2, Asteroids—Dynamic Site
- Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
- 464 Megaira at the JPL Small-Body Database
