1453 Fennia, provisional designation 1938 ED1, is a stony Hungaria asteroid and synchronous binary system from the innermost regions of the asteroid belt, approximately 7 kilometers in diameter. Discovered by Yrjö Väisälä at the Turku Observatory in 1938,[23] the asteroid was later named after the Scandinavian country of Finland.[2] The system's minor-planet moon was discovered in 2007. It has a derived diameter of 1.95 kilometers and is orbiting its primary every 23.55 hours.[6][7]

1453 Fennia
Discovery [1]
Discovered byY. Väisälä
Discovery siteTurku Obs.
Discovery date8 March 1938
MPC designation(1453) Fennia
Named after
Finland (Scandinavian country)[2]
1938 ED1
main-belt · (inner)
Hungaria[3] · background[4]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc79.50 yr (29,037 days)
Aphelion1.9502 AU
Perihelion1.8438 AU
1.8970 AU
2.61 yr (954 days)
0° 22m 37.92s / day
Known satellites1 (D: 1.95 km; P: 23.55 h)[5][6][7]
Physical characteristics
Dimensions6.36±0.68 km[8]
6.573±0.245 km[9]
6.96±0.39 km (derived)[6]
7.23±0.4 km[10]
7.32 km[3][11]
8.98±0.28 km[12]
4.412±0.002 h[7][a]
4.4121±0.0001 h[11][13][b]
4.41224±0.0004 h[14]
4.4124±0.0004 h[15]
4.413±0.002 h[16]
6±1 h[17]
12.23±0.04 h (wrong)[18]
Tholen = S[1][3] · K[20]
B–V = 0.928[1]
B–V = 0.890±0.030[11]
U–B = 0.532 [1]
V–R = 0.500±0.020[11]
V–I = 0.980±0.020[11]
12.38±0.05 (R)[14] · 12.50[1][8][9] · 12.69[12] · 12.81±0.06[17] · 12.82±0.24[21] · 12.83[10] · 12.83±0.07[11] · 12.835[3] · 12.835±0.06[22]


Fennia was discovered on 8 March 1938, by Finnish astronomer Yrjö Väisälä at the Iso-Heikkilä Observatory in Turku, southwest Finland.[23] Fifteen days later, it was independently discovered by Soviet astronomer Grigory Neujmin at the Simeiz Observatory on the Crimean peninsula, which also served as a confirmation of the first observation.[1][2] The Minor Planet Center only recognizes the first discoverer.[23]

Orbit and classificationEdit

Fennia is a bright member of the Hungaria asteroids,[23] a dynamical group that forms the innermost dense concentration of asteroids in the Solar System. The group includes all members of large asteroid family of the same name (003). When applying the Hierarchical Clustering Method to its proper orbital elements, Fennia is a non-family asteroid of the main belt's background population.[4]

It orbits the Sun in the inner main-belt at a distance of 1.8–2.0 AU once every 2 years and 7 months (954 days). Its orbit has an eccentricity of 0.03 and an inclination of 24° with respect to the ecliptic.[1] The body's observation arc begins at the discovering observatory (or at Simeiz Observatory), 15 days after its official discovery observation at Turku.[23]

Physical characteristicsEdit

In the Tholen classification, Fennia is a common, stony S-type asteroid. It has also been characterized as a rare K-type asteroid.[20]

Rotation periodEdit

Since 1991, a large number of rotational lightcurves of Fennia have been obtained from photometric observations. Lightcurve analysis gave a consolidated rotation period of 4.4121 hours with a brightness amplitude between 0.10 and 0.20 magnitude (U=0/3/3/3/3/3-).[7][13][11][14][15][16][17][18][b][a] Due to its relatively low brightness amplitude, Fennia is likely spheroidal in shape.


In 2007, these photometric lightcurve observations revealed that Fennia is a synchronous binary asteroid, orbited by a minor-planet moon.[5][6] The moon has an orbital period of 22.99 hours,[11][13][b] later revised to 23.55 hours.[7][a] It is at least a quarter the size of Fennia itself – a secondary-to-primary mean-diameter ratio of 0.28±0.02) – which translates into a diameter of 1.95±0.18 kilometers based on current estimates.[6]

Diameter and albedoEdit

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, Fennia measures between 6.36 and 8.98 kilometers in diameter and its surface has an albedo between 0.140 and 0.50.[8][9][10][11][12][19]

The Johnston's archive derives a diameter of 6.96 kilometers,[6] while Collaborative Asteroid Lightcurve Link adopts an albedo of 0.244 and a diameter of 7.32 kilometers using an absolute magnitude of 12.835, taken from the revised WISE-results.[3][11]


This minor planet was named in honor of the Scandinavian country of Finland. "Fennia" is the Latin word for Finland. The official naming citation was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 130).[2]


  1. ^ a b c Lightcurve plot of 1453 Fennia, Palmer Divide Station, California, Brian D. Warner (2016). rotation period 4.412±0.002 hours with a brightness amplitude of 0.19 mag, and P2-chart with an orbital period of 23.55±0.05 hours. Summary figures at LCDB
  2. ^ a b c Lightcurve plot of 1453 Fennia, Palmer Divide Observatory, Colorado, Brian D. Warner (2007) rotation period 4.4121±0.0001 hours with a brightness amplitude of 0.10±0.01 mag, including primary–secondary mutual eclipsing/occultation event chart with an orbital period of 22.99±0.05. Summary figures at LCDB


  1. ^ a b c d e f g h "JPL Small-Body Database Browser: 1453 Fennia (1938 ED1)" (2017-10-01 last obs.). Jet Propulsion Laboratory. Retrieved 21 October 2017.
  2. ^ a b c d Schmadel, Lutz D. (2007). "(1453) Fennia". Dictionary of Minor Planet Names – (1453) Fennia. Springer Berlin Heidelberg. p. 116. doi:10.1007/978-3-540-29925-7_1454. ISBN 978-3-540-00238-3.
  3. ^ a b c d e "LCDB Data for (1453) Fennia". Asteroid Lightcurve Database (LCDB). Retrieved 21 October 2017.
  4. ^ a b "Asteroid 1453 Fennia – Proper Elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 29 October 2019.
  5. ^ a b "Electronic Telegram No. 1150: (1453) Fennia". Central Bureau for Astronomical Telegrams. 1 December 2007. Retrieved 21 October 2017.
  6. ^ a b c d e f "Asteroids with Satellites Database – Johnston's Archive: (1453) Fennia". Johnston's Archive. 21 September 2014. Retrieved 21 October 2017.
  7. ^ a b c d e Warner, Brian D. (July 2016). "Asteroid Lightcurve Analysis at CS3-Palmer Divide Station: 2015 December - 2016 April". The Minor Planet Bulletin. 43 (3): 227–233. Bibcode:2016MPBu...43..227W. ISSN 1052-8091.
  8. ^ a b c d 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. arXiv:1509.02522. Bibcode:2015ApJ...814..117N. doi:10.1088/0004-637X/814/2/117.
  9. ^ a b c d 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. arXiv:1209.5794. Bibcode:2012ApJ...759L...8M. doi:10.1088/2041-8205/759/1/L8.
  10. ^ 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. 12: IRAS-A-FPA-3-RDR-IMPS-V6.0. Bibcode:2004PDSS...12.....T. Retrieved 22 October 2019.
  11. ^ a b c d e f g h i j k Warner, Brian D.; Harris, Alan W.; Pravec, Petr; Stephens, Robert D.; Pray, Donald P.; Cooney, Walter R., Jr.; et al. (June 2008). "1453 Fennia: A Hungaria Binary". The Minor Planet Bulletin. 35 (2): 73–74. Bibcode:2008MPBu...35...73W. ISSN 1052-8091.
  12. ^ 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. Retrieved 17 October 2019. (online, AcuA catalog p. 153)
  13. ^ a b c Warner, B. D.; Harris, A. W.; Pravec, P.; Stephens, R. D.; Pray, D.; Cooney, W.; et al. (December 2007). "(1453) Fennia". Central Bureau Electronic Telegrams. 1150 (1150): 1. Bibcode:2007CBET.1150....1W.
  14. ^ a b c Pravec, P.; Scheirich, P.; Vokrouhlický, D.; Harris, A. W.; Kusnirák, P.; Hornoch, K.; et al. (March 2012). "Binary asteroid population. 2. Anisotropic distribution of orbit poles of small, inner main-belt binaries". Icarus. 218 (1): 125–143. Bibcode:2012Icar..218..125P. doi:10.1016/j.icarus.2011.11.026.
  15. ^ a b Higgins, David; Oey, Julian; Pravec, Petr (January 2011). "Period Determination of Binary Asteroid Targets Observed at Hunters Hill Observatory: May-September 2009". The Minor Planet Bulletin. 38 (1): 46–49. Bibcode:2011MPBu...38...46H. ISSN 1052-8091.
  16. ^ a b Santana-Ros, Toni; Marciniak, Anna; Bartczak, Prezemyslaw (July 2016). "Gaia-GOSA: A Collaborative Service for Asteroid Observers". The Minor Planet Bulletin. 43 (3): 205–207. Bibcode:2016MPBu...43..205S. ISSN 1052-8091.
  17. ^ a b c Wisniewski, W. Z.; Michalowski, T. M.; Harris, A. W.; McMillan, R. S. (March 1995). "Photoelectric Observations of 125 Asteroids". Abstracts of the Lunar and Planetary Science Conference. 26: 1511. Bibcode:1995LPI....26.1511W.
  18. ^ a b Behrend, Raoul. "Asteroids and comets rotation curves – (1453) Fennia". Geneva Observatory. Retrieved 21 October 2017.
  19. ^ a b Gil-Hutton, R.; Lazzaro, D.; Benavidez, P. (June 2007). "Polarimetric observations of Hungaria asteroids". Astronomy and Astrophysics. 468 (3): 1109–1114. Bibcode:2007A&A...468.1109G. doi:10.1051/0004-6361:20077178.
  20. ^ a b Belskaya, I. N.; Fornasier, S.; Tozzi, G. P.; Gil-Hutton, R.; Cellino, A.; Antonyuk, K.; et al. (March 2017). "Refining the asteroid taxonomy by polarimetric observations". Icarus. 284: 30–42. Bibcode:2017Icar..284...30B. doi:10.1016/j.icarus.2016.11.003.
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External linksEdit