Astronomy:5176 Yoichi
| Discovery [1] | |
|---|---|
| Discovered by | S. Ueda H. Kaneda |
| Discovery site | Kushiro Obs. |
| Discovery date | 4 January 1989 |
| Designations | |
| (5176) Yoichi | |
| Named after | Yoichi [1] (Japanese town) |
| 1989 AU · 1935 YH 1948 VS · 1948 WS 1952 OH1 · 1961 TK1 | |
| Minor planet category | main-belt [1][2] · (middle) background [3] |
| Orbital characteristics [2] | |
| Epoch 23 March 2018 (JD 2458200.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 81.52 yr (29,777 d) |
| |{{{apsis}}}|helion}} | 3.5198 AU |
| |{{{apsis}}}|helion}} | 1.8546 AU |
| 2.6872 AU | |
| Eccentricity | 0.3098 |
| Orbital period | 4.41 yr (1,609 d) |
| Mean anomaly | 295.85° |
| Mean motion | 0° 13m 25.32s / day |
| Inclination | 7.7043° |
| Longitude of ascending node | 93.615° |
| 269.81° | |
| Physical characteristics | |
| Mean diameter | 15.68±1.57 km[4] 16.54 km (derived)[5] 16.56±0.7 km[6] 16.74±4.79 km[7] 18.92±5.20 km[8] 19.49±1.15 km[9] |
| Geometric albedo | 0.05±0.03[7] 0.054±0.048[8] 0.06±0.03[4] 0.061±0.008[9] 0.0777 (derived)[5] 0.0849±0.007[6] |
| S (assumed)[5] | |
| Absolute magnitude (H) | 12.20[7][9] 12.3[2][5] 12.36±0.26[10] 12.40[8] 12.57[4] |
5176 Yoichi, provisional designation 1989 AU, is a background asteroid from the central regions of the asteroid belt, approximately 17 kilometers (11 miles) in diameter. It was discovered on 4 January 1989, by Japanese astronomers Seiji Ueda and Hiroshi Kaneda at the Kushiro Observatory on Hokkaido, Japan.[1] The likely elongated asteroid has a brightness variation of 0.45 magnitude,[11] and occulted a star in the constellation Cetus in November 2014.[12] It was named for the Japanese town of Yoichi.[1]
Orbit and classification
Yoichi is a non-family asteroid from the main belt's background population.[3] It orbits the Sun in the central main-belt at a distance of 1.9–3.5 AU once every 4 years and 5 months (1,609 days; semi-major axis of 2.69 AU). Its orbit has an eccentricity of 0.31 and an inclination of 8° with respect to the ecliptic.[2]
The body's observation arc begins with its first observations as 1935 YH at Johannesburg Observatory in December 1935, or 53 years prior to its official discovery observation at Kushiro.[1]
Physical characteristics
Yoichi is an assumed S-type asteroid, while the body's albedo is rather indicative of a carbonaceous C-type asteroid (see below).[5]
Rotation period
In November 2015, photometric data of Yoichi was taken by astronomers at the Oakley Southern Sky Observatory in Australia. However no rotational lightcurve could be constructed. The asteroid's brightness amplitude was 0.42 magnitude ({{{1}}}), indicative for an elongated shape.[11] As of 2018, the body's rotation period, pole and shape remain unknown.[5]
Diameter and albedo
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, Yoichi measures between 15.68 and 19.49 kilometers in diameter and its surface has an albedo between 0.05 and 0.0849.[4][6][7][8][9]
The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0777 and a diameter of 16.54 kilometers based on an absolute magnitude of 12.3.[5]
Occultation
On 2 November 2014, Yoichi occulted 8.4 magnitude star HIP 14421 in the constellation Cetus, causing a magnitude drop from 8.4 to 14.1 during 2.8 seconds. The occultation was visible over Southern Japan, Eastern China, as well as from Southern California to North Florida. The asteroid's 23-kilometer-wide shadow had a speed of approximately 6.8 km/s. An approximate diameter of 20 kilometers was assumed for the asteroid.[12]
Naming
This minor planet was named after the Japanese town of Yoichi on Hokkaido, where the discovering Kushiro Observatory is located.[1] The official naming citation was published by the Minor Planet Center on 4 August 2001 (M.P.C. 43189).[13]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 "5176 Yoichi (1989 AU)". Minor Planet Center. https://www.minorplanetcenter.net/db_search/show_object?object_id=5176.
- ↑ 2.0 2.1 2.2 2.3 "JPL Small-Body Database Browser: 5176 Yoichi (1989 AU)". Jet Propulsion Laboratory. https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2005176.
- ↑ 3.0 3.1 "Asteroid 5176 Yoichi – Proper Elements". AstDyS-2, Asteroids – Dynamic Site. https://newton.spacedys.com/astdys/index.php?pc=1.1.6&n=5176.
- ↑ 4.0 4.1 4.2 4.3 Nugent, C. R.; Mainzer, A.; Bauer, J.; Cutri, R. M.; Kramer, E. A.; Grav, T. et al. (September 2016). "NEOWISE Reactivation Mission Year Two: Asteroid Diameters and Albedos". The Astronomical Journal 152 (3): 12. doi:10.3847/0004-6256/152/3/63. Bibcode: 2016AJ....152...63N.
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 5.6 "LCDB Data for (5176) Yoichi". Asteroid Lightcurve Database (LCDB). http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=5176%7CYoichi.
- ↑ 6.0 6.1 6.2 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. https://sbnarchive.psi.edu/pds3/iras/IRAS_A_FPA_3_RDR_IMPS_V6_0/data/diamalb.tab. Retrieved 22 October 2019.
- ↑ 7.0 7.1 7.2 7.3 Nugent, C. R.; Mainzer, A.; Masiero, J.; Bauer, J.; Cutri, R. M.; Grav, T. et al. (December 2015). "NEOWISE Reactivation Mission Year One: Preliminary Asteroid Diameters and Albedos". The Astrophysical Journal 814 (2): 13. doi:10.1088/0004-637X/814/2/117. Bibcode: 2015ApJ...814..117N.
- ↑ 8.0 8.1 8.2 8.3 Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Nugent, C. et al. (November 2012). "Preliminary Analysis of WISE/NEOWISE 3-Band Cryogenic and Post-cryogenic Observations of Main Belt Asteroids". The Astrophysical Journal Letters 759 (1): 5. doi:10.1088/2041-8205/759/1/L8. Bibcode: 2012ApJ...759L...8M.
- ↑ 9.0 9.1 9.2 9.3 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. doi:10.1093/pasj/63.5.1117. Bibcode: 2011PASJ...63.1117U. (online, AcuA catalog p. 153)
- ↑ 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. doi:10.1016/j.icarus.2015.08.007. Bibcode: 2015Icar..261...34V.
- ↑ 11.0 11.1 Hess, Kylie; Ditteon, Richard (April 2016). "Asteroid Lightcurve Analysis at the Oakley Southern Sky Observatory: 2014 November". The Minor Planet Bulletin 43 (2): 120. ISSN 1052-8091. Bibcode: 2016MPBu...43..120H.
- ↑ 12.0 12.1 Preston, Steve. "(5176) Yoichi / HIP 14421 event on 2014 Nov 02, 10:58 UT". http://asteroidoccultation.com/2014_11/1102_5176_33533.htm. (Summary)
- ↑ "MPC/MPO/MPS Archive". Minor Planet Center. https://www.minorplanetcenter.net/iau/ECS/MPCArchive/MPCArchive_TBL.html.
External links
- Asteroid Lightcurve Database (LCDB), query form (info )
- Dictionary of Minor Planet Names, Google books
- Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
- Discovery Circumstances: Numbered Minor Planets (5001)-(10000) – Minor Planet Center
- 5176 Yoichi at AstDyS-2, Asteroids—Dynamic Site
- 5176 Yoichi at the JPL Small-Body Database
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