1657 Roemera

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1657 Roemera
Discovery [1]
Discovered by P. Wild
Discovery site Zimmerwald Obs.
Discovery date 6 March 1961
MPC designation 1657 Roemera
Named after
Elizabeth Roemer
1961 EA · 1932 AB
main-belt · (inner)[3]
Orbital characteristics[1]
Epoch 16 February 2017 (JD 2457800.5)
Uncertainty parameter 0
Observation arc 84.58 yr (30,893 days)
Aphelion 2.9033 AU
Perihelion 1.7943 AU
2.3488 AU
Eccentricity 0.2361
3.60 yr (1,315 days)
Inclination 23.373°
Physical characteristics
Dimensions 7.665±0.219 km[4]
8.04 km (calculated)[3]
4.5±1 h[5]
34.0±0.1 h[6]
0.20 (assumed)[3]
Tholen = S[1] · S[3]
12.84[1][4] · 12.89±0.16[3][5][7]

1657 Roemera, provisional designation 1961 EA, is a stony asteroid from the inner regions of the asteroid belt, approximately 8 kilometers in diameter. It was discovered on 6 March 1961, by Swiss astronomer Paul Wild at Zimmerwald Observatory near Bern, Switzerland.[8]

Roemera is a stony S-type asteroid. It orbits the Sun at a distance of 1.8–2.9 AU once every 3 years and 7 months (1,315 days). Its orbit has an eccentricity of 0.24 and an inclination of 23° with respect to the ecliptic.[1] Roemera was first identified as 1932 AB at Heidelberg Observatory in 1932, extending the body's observation arc by 29 years prior to its official discovery observation.[8]

In May 2008, American astronomer Brian D. Warner obtained a rotational light-curve of Roemera from photometric observations at his Palmer Divide Observatory in Colorado. It gave a longer than average rotation period of 34.0 hours with a brightness variation of 0.15 magnitude (U=2).[6] Polish astronomer Wiesław Z. Wiśniewski found a different period solution of 4.5 hours with a low amplitude of 0.09 magnitude in March 1990 (U=2).[5]

According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Roemera measures 7.66 kilometers in diameter and its surface has an albedo of 0.220,[4] while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 8.04 kilometers based on an absolute magnitude of 12.89.[3]

This minor planet was named by the discoverer in honor American astronomer Elizabeth Roemer (b. 1929), U.S. Naval Observatory, in appreciation of her untiring and successful efforts to advance the knowledge of the motions and physical properties of comets and minor planets.[2] Roemer herself discovered the asteroids 1930 Lucifer and 1983 Bok. Naming citation was published before November 1977 (M.P.C. 2347).[9]


  1. ^ a b c d e "JPL Small-Body Database Browser: 1657 Roemera (1961 EA)" (2016-08-09 last obs.). Jet Propulsion Laboratory. Retrieved 24 December 2016. 
  2. ^ a b Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (1657) Roemera. Springer Berlin Heidelberg. p. 132. ISBN 978-3-540-00238-3. Retrieved 24 December 2016. 
  3. ^ a b c d e f "LCDB Data for (1657) Roemera". Asteroid Lightcurve Database (LCDB). Retrieved 24 December 2016. 
  4. ^ 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:1209.5794Freely accessible. Bibcode:2012ApJ...759L...8M. doi:10.1088/2041-8205/759/1/L8. Retrieved 24 December 2016. 
  5. ^ 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. Bibcode:1995LPI....26.1511W. Retrieved 24 December 2016. 
  6. ^ a b Warner, Brian D. (January 2009). "Asteroid Lightcurve Analysis at the Palmer Divide Observatory: 2008 May - September". The Minor Planet Bulletin. 36 (1): 7–13. Bibcode:2009MPBu...36....7W. ISSN 1052-8091. Retrieved 24 December 2016. 
  7. ^ Pravec, Petr; Harris, Alan W.; Kusnirák, Peter; Galád, Adrián; Hornoch, Kamil (September 2012). "Absolute magnitudes of asteroids and a revision of asteroid albedo estimates from WISE thermal observations". Icarus. 221 (1): 365–387. Bibcode:2012Icar..221..365P. doi:10.1016/j.icarus.2012.07.026. Retrieved 24 December 2016. 
  8. ^ a b "1657 Roemera (1961 EA)". Minor Planet Center. Retrieved 24 December 2016. 
  9. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 24 December 2016. 

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