1313 Berna

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1313 Berna
Discovery [1]
Discovered by S. Arend
Discovery site Uccle Obs.
Discovery date 24 August 1933
Designations
MPC designation (1313) Berna
Named after
Bern (capital city)[2]
1933 QG · 1926 EA
A911 OA
main-belt · Eunomia[3]
Orbital characteristics[1]
Epoch 16 February 2017 (JD 2457800.5)
Uncertainty parameter 0
Observation arc 83.20 yr (30,389 days)
Aphelion 3.2081 AU
Perihelion 2.1037 AU
2.6559 AU
Eccentricity 0.2079
4.33 yr (1,581 days)
60.111°
0° 13m 39.72s / day
Inclination 12.534°
298.35°
99.223°
Known satellites 1 (see 2nd infobox)[a]
Physical characteristics
Dimensions 13.12±2.44 km[4]
13.3±1.4 km[5]
13.504±0.311 km[6][7]
13.88 km (calculated)[3]
13.93±0.64 km[8]
14.27±0.36 km[9]
19.96±4.97 km[10]
Mass (2.25±2.00)×1015 kg[8]
Mean density
1.21±0.14 g/cm3[8]
6 h[11]
25.4±0.3 h[11]
25.46±0.01 h[11]
25.46 h[5][12]
25.464 h[13]
0.13±0.06[10]
0.169±0.009[9]
0.185±0.020[6][7]
0.21 (assumed)[3]
0.212±0.076[5]
0.245±0.158[4]
S[3]
11.55[4] · 11.6[1][3] · 11.69±0.12[5] · 11.75[10] · 11.80[6][9] · 11.89±0.48[14]

1313 Berna, provisional designation 1933 QG, is a binary Eunomian asteroid from the middle region of the asteroid belt, approximately 15 kilometers in diameter. It was discovered on 24 August 1933, by Belgian astronomer Sylvain Arend at the Uccle Observatory in Belgium, and named for the Swiss capital of Bern.[15] Berna's 2004-discovered synchronous moon measures approximately 11 kilometers.[a]

Description[edit]

Berna is a member of the Eunomia family, a prominent group of stony S-type asteroids and the largest family in the intermediate main-belt. It orbits the Sun at a distance of 2.1–3.2 AU once every 4 years and 4 months (1,581 days). Its orbit has an eccentricity of 0.21 and an inclination of 13° with respect to the ecliptic.[1] In 1911, Berna was first identified as A911 OA at Johannesburg, its observation arc begins with its official discovery observation at Uccle.[15]

A network of astronomers at several observatories including Raoul Behrend at Geneva Observatory, Switzerland, obtained the so-far best rated rotational light-curve of Berna. Light-curve analysis gave a rotation period of 25.464 hours with a brightness variation of 0.28 magnitude (U=3).[13] In November 2007, photometric observations at Cerro Tololo, Chile, using its 0.9-meter Prompt5 telescope in combination with the Spitzer Space Telescope gave a concurring period of 25.46 hours with an amplitude of 0.5 magnitude (U=n.a.).[5]:40 Other light-curves were also obtained by several amateur astronomers giving a period of 6, 25.4 and 25.45 hours, respectively (U=1/2-/3-).[11]

According to the surveys carried out by the Japanese Akari satellite, NASA's Spitzer Space Telescope and the Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Berna measures between 13.12 and 19.96 kilometers in diameter and its surface has an albedo between 0.12 and 0.245.[4][5][6][7][9][10] The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.21 – derived from 15 Eunomia, the family's largest member and namesake – and calculates a diameter of 13.88 kilometers based on an absolute magnitude of 11.6.[3]

Asteroid moon[edit]

S/2004 (1313) 1
Discovery [a]
Discovered by R. Behrend, R. Roy
S. Sposetti
Discovery date 6 February 2004
Light-curve
Orbital characteristics
25 km
25.464±0.001 h[5][12]
30 mas (maximum)
Satellite of 1313 Berna
Physical characteristics
Dimensions 8.37 km[16]
Δ0.51 fainter than prim.
12.8–13.0

In 2004, a satellite orbiting the asteroid was discovered. The moon, designated S/2004 (1313) 1, measures about 11 kilometers in diameter and orbits Berna at a distance of 35 kilometer once every 25 hours and 28 minutes, since the lightcurve is synchronized with the eclipse events, at least one body of the binary system rotates synchronously with the orbital motion. It was identified based on light-curve observations taken in February 2004 by several astronomers, including Raoul Behrend at Geneva Observatory, Stefano Sposetti, René Roy, Donald Pray, Christophe Demeautis, Daniel Matter, Alain Klotz and others.[a][12] Although the IAUC was released on 23 February 2004, the announcement was already made on 12 February 2004. There are several hundreds of asteroids known to have satellites (also see Category:Binary asteroids).[17]

Naming[edit]

The minor planet was named after the Swiss capital city of Bern, the name was proposed by Sigmund Mauderli (1876–1962), astronomer and director of the Astronomical Institute at the University of Bern, after whom 1748 Mauderli is named. He computed the definitive orbit of the body, and also insisted to rename the minor planet to its current name, after it had been originally published as "Bernia".[2] Naming citation was first mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 120).[2]

References[edit]

  1. ^ a b c d International Astronomical Union Circular (No.8292), 23 February 2004 for (1313) BERNA:

    "Photometric observations obtained of the minor planet (1313) on eight nights during Feb. 6–16 show a lightcurve of amplitude 0.25 mag and suggest that this is a binary system with an orbital period of 1.061 ± 0.005 days, showing mutual eclipses and/or occultations near both rotational lightcurve minima with a duration of about 0.09 day and depth about 0.7 mag, the first being centered on Feb. 7.85 UT. The regular-appearing lightcurve is synchronized with the eclipse events, indicating that at least one of the two bodies is elongated and rotates synchronously with the orbital motion; the sharp eclipse/occultation events indicate that both components have approximately the same size. The maximum orbital separation observed from earth would be about 0".03."

    Reported by R. Behrend, Geneva Observatory, on behalf of R. Roy, S. Sposetti, N. Waelchli, D. Pray, N. Berger, C. Demeautis, D.Matter, R. Durkee, A. Klotz, D. Starkey, and V. Cotrez)
  1. ^ a b c d "JPL Small-Body Database Browser: 1313 Berna (1933 QG)" (2016-11-05 last obs.). Jet Propulsion Laboratory. Retrieved 16 January 2017. 
  2. ^ a b c Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (1313) Berna. Springer Berlin Heidelberg. p. 107. ISBN 978-3-540-00238-3. Retrieved 16 January 2017. 
  3. ^ a b c d e f "LCDB Data for (1313) Berna". Asteroid Lightcurve Database (LCDB). Retrieved 16 January 2017. 
  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 16 January 2017. 
  5. ^ a b c d e f g Marchis, F.; Enriquez, J. E.; Emery, J. P.; Mueller, M.; Baek, M.; Pollock, J.; et al. (November 2012). "Multiple asteroid systems: Dimensions and thermal properties from Spitzer Space Telescope and ground-based observations". Icarus. 221 (2): 1130–1161. arXiv:1604.05384Freely accessible. Bibcode:2012Icar..221.1130M. doi:10.1016/j.icarus.2012.09.013. Retrieved 16 January 2017. 
  6. ^ a b c d Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; Bauer, J.; Tholen, D.; et al. (November 2011). "NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results" (PDF). The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407Freely accessible. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. Retrieved 16 January 2017. 
  7. ^ a b c Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Dailey, J.; et al. (November 2011). "Main Belt Asteroids with WISE/NEOWISE. I. Preliminary Albedos and Diameters". The Astrophysical Journal. 741 (2): 20. arXiv:1109.4096Freely accessible. Bibcode:2011ApJ...741...68M. doi:10.1088/0004-637X/741/2/68. Retrieved 16 January 2017. 
  8. ^ a b c Carry, B. (December 2012). "Density of asteroids". Planetary and Space Science. 73 (1): 98–118. arXiv:1203.4336Freely accessible. Bibcode:2012P&SS...73...98C. doi:10.1016/j.pss.2012.03.009. Retrieved 24 November 2015. 
  9. ^ 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 16 January 2017. 
  10. ^ a b c d 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. arXiv:1606.08923Freely accessible. Bibcode:2016AJ....152...63N. doi:10.3847/0004-6256/152/3/63. Retrieved 16 January 2017. 
  11. ^ a b c d Behrend, Raoul. "Asteroids and comets rotation curves – (1313) Berna". Geneva Observatory. Retrieved 16 January 2017. 
  12. ^ a b c Behrend, R.; Roy, R.; Sposetti, S.; Waelchli, N.; Pray, D.; Berger, N.; et al. (February 2004). "(1313) Berna". IAU Circ. (8292). Bibcode:2004IAUC.8292....3B. Retrieved 16 January 2017. 
  13. ^ a b Behrend, R.; Bernasconi, L.; Roy, R.; Klotz, A.; Colas, F.; Antonini, P.; et al. (February 2006). "Four new binary minor planets: (854) Frostia, (1089) Tama, (1313) Berna, (4492) Debussy" (PDF). Astronomy and Astrophysics. 446 (3): 1177–1184. Bibcode:2006A&A...446.1177B. doi:10.1051/0004-6361:20053709. Retrieved 16 January 2017. 
  14. ^ 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. arXiv:1506.00762Freely accessible. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. Retrieved 16 January 2017. 
  15. ^ a b "1313 Berna (1933 QG)". Minor Planet Center. Retrieved 16 January 2017. 
  16. ^ Johnston, Robert. "(131) Berna". johnstonsarchive.net. Retrieved 28 May 2015. 
  17. ^ Wm. Robert Johnston (1 November 2015). "Asteroids with Satellites". Johnston's Archive. Retrieved 24 November 2015. 

External links[edit]