Astronomy:889 Erynia

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889 Erynia
000889-asteroid shape model (889) Erynia.png
Modelled shape of Erynia from its lightcurve
Discovery [1]
Discovered byM. F. Wolf
Discovery siteHeidelberg Obs.
Discovery date5 March 1918
Designations
(889) Erynia
Pronunciation/ɛˈrniə/
Named afterErinyes, or Furies
(Greek mythology)[2]
A918 EN · 1929 BG
A912 PA · 1912 PA
1918 DG
Minor planet categorymain-belt [1][3] · (inner)
background[4][5]
Orbital characteristics[3]
Epoch 31 May 2020 (JD 2459000.5)
Uncertainty parameter 0
Observation arc101.81 yr (37,187 d)
|{{{apsis}}}|helion}}2.9428 AU
|{{{apsis}}}|helion}}1.9500 AU
2.4464 AU
Eccentricity0.2029
Orbital period3.83 yr (1,398 d)
Mean anomaly342.62°
Mean motion0° 15m 27.36s / day
Inclination8.1064°
Longitude of ascending node132.53°
278.52°
Physical characteristics
Mean diameter
Rotation period9.89±0.01 h[8]
Pole ecliptic latitude
  • (187.0°, −60.0°) (λ11)[5][9]
  • (335.0°, −74.0°) (λ22)[5][9]
Geometric albedo
  • 0.196±0.014[7]
  • 0.230±0.042[6]
Absolute magnitude (H)11.0[1][3]


889 Erynia /ɛˈrniə/ is a highly elongated background asteroid from the inner regions of the asteroid belt. It was discovered on 5 March 1918, by German astronomer Max Wolf at the Heidelberg-Königstuhl State Observatory, and given the provisional designations A918 EN and 1918 DG.[1] The stony S-type asteroid (Sl) has a rotation period of 9.89 hours and measures approximately 17 kilometers (11 miles) in diameter. It was named from Greek mythology, after the Erinyes, also known as Furies.[2]

Orbit and classification

Erynia is a non-family asteroid of the main belt's background population when applying the hierarchical clustering method to its proper orbital elements.[4][5] It orbits the Sun in the inner asteroid belt at a distance of 2.0–2.9 AU once every 3 years and 10 months (1,398 days; semi-major axis of 2.45 AU). Its orbit has an eccentricity of 0.20 and an inclination of 8° with respect to the ecliptic.[3] The asteroid was first observed as A912 PA (1912 PA) at the Johannesburg Observatory on 7 August 1912. The body's observation arc begins at Heidelberg Observatory on 16 March 1918, or eleven nights after its official discovery observation.[1]

Naming

This minor planet was named after one of the Erinyes from Greek mythology, also known as Furies in Roman mythology. The female deities of vengeance have snakes for hair, dog's heads, coal black bodies, bat's wings, and blood-shot eyes. They tortured their victims with brass-studded scourges and inflicted plagues. The naming was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 86).[2]

Physical characteristics

In the Tholen-like taxonomy of the Small Solar System Objects Spectroscopic Survey (S3OS2), Erynia is a common stony S-type asteroid, while in the SMASS-like taxonomic variant of the survey, it is an Sl-subtype, which transitions from the S- to the uncommon L-type.[5][10]

Rotation period and poles

Lightcurve-based 3D-model of Erynia

In January 2002, a rotational lightcurve of Erynia was obtained from photometric observations by French astronomer Laurent Bernasconi. Lightcurve analysis gave a rotation period of 9.89±0.01 hours with a high brightness variation of 0.67±0.02 magnitude, indicative of a non-spherical, elongated shape ({{{1}}}).[8] A concurring period of 9.872±0.0079 hours and an amplitude 0.47 magnitude was obtained by astronomers at the Palomar Transient Factory in April 2010 ({{{1}}}).[11][12] In 2011, a modeled lightcurve using data from the Uppsala Asteroid Photometric Catalogue (UAPC) and other sources gave a sidereal period 9.8749±0.0005 hours, as well as two spin axes at (187.0°, −60.0°) and (335.0°, −74.0°) in ecliptic coordinates (λ, β).[9]

Diameter and albedo

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE) and the Japanese Akari satellite, Erynia measures (16.682±0.154) and (18.14±0.59) kilometers in diameter and its surface has an albedo of (0.230±0.042) and (0.196±0.014), respectively.[6][7] The Collaborative Asteroid Lightcurve Link assumes a standard albedo for a stony asteroid of 0.20 and calculates a diameter of 18.75 kilometers based on an absolute magnitude of 11.[12] The WISE team also published a mean-diameter of (17.386±0.181 km) with a corresponding albedo of (0.2171±0.0295).[5][12]

References

  1. 1.0 1.1 1.2 1.3 1.4 "889 Erynia (A918 EN)". Minor Planet Center. https://www.minorplanetcenter.net/db_search/show_object?object_id=889. 
  2. 2.0 2.1 2.2 Schmadel, Lutz D. (2007). "(889) Erynia". Dictionary of Minor Planet Names. Springer Berlin Heidelberg. p. 80. doi:10.1007/978-3-540-29925-7_890. ISBN 978-3-540-00238-3. 
  3. 3.0 3.1 3.2 3.3 "JPL Small-Body Database Browser: 889 Erynia (A918 EN)". Jet Propulsion Laboratory. https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2000889. 
  4. 4.0 4.1 "Asteroid 889 Erynia – Proper Elements". AstDyS-2, Asteroids – Dynamic Site. https://newton.spacedys.com/astdys/index.php?pc=1.1.6&n=889. 
  5. 5.0 5.1 5.2 5.3 5.4 5.5 "Asteroid 889 Erynia". Small Bodies Data Ferret. https://sbntools.psi.edu/ferret/SimpleSearch/results.action?targetName=889+Erynia. 
  6. 6.0 6.1 6.2 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. doi:10.1088/0004-637X/791/2/121. Bibcode2014ApJ...791..121M. 
  7. 7.0 7.1 7.2 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. Bibcode2011PASJ...63.1117U.  (online, AcuA catalog p. 153)
  8. 8.0 8.1 Behrend, Raoul. "Asteroids and comets rotation curves – (889) Erynia". Geneva Observatory. http://obswww.unige.ch/~behrend/page3cou.html#000889. 
  9. 9.0 9.1 9.2 Hanuš, J.; Ďurech, J.; Brož, M.; Warner, B. D.; Pilcher, F.; Stephens, R. et al. (June 2011). "A study of asteroid pole-latitude distribution based on an extended set of shape models derived by the lightcurve inversion method". Astronomy and Astrophysics 530: A134. doi:10.1051/0004-6361/201116738. ISSN 0004-6361. Bibcode2011A&A...530A.134H. 
  10. 10.0 10.1 10.2 Lazzaro, D.; Angeli, C. A.; Carvano, J. M.; Mothé-Diniz, T.; Duffard, R.; Florczak, M. (November 2004). "S3OS2: the visible spectroscopic survey of 820 asteroids". Icarus 172 (1): 179–220. doi:10.1016/j.icarus.2004.06.006. Bibcode2004Icar..172..179L. http://sirrah.troja.mff.cuni.cz/yarko-site/tmp/eos/NEW/spectral_type_figure/s3os2.pdf. Retrieved 26 February 2020. 
  11. 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): 75. doi:10.1088/0004-6256/150/3/75. ISSN 0004-6256. Bibcode2015AJ....150...75W. 
  12. 12.0 12.1 12.2 "LCDB Data for (889) Erynia". Asteroid Lightcurve Database (LCDB). http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=889. 

External links