797 Montana

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797 Montana
Discovery [1]
Discovered by H. Thiele
Discovery site Bergedorf Obs.
Discovery date 17 November 1914
MPC designation (797) Montana
Named after
Bergedorf Observatory
Latin for "mountain village"[2]
1914 VR · 1953 JG
1957 MG · A898 WA
main-belt · (middle)
Orbital characteristics[1]
Epoch 16 February 2017 (JD 2457800.5)
Uncertainty parameter 0
Observation arc 101.83 yr (37,194 days)
Aphelion 2.6904 AU
Perihelion 2.3793 AU
2.5348 AU
Eccentricity 0.0614
4.04 yr (1,474 days)
0° 14m 39.12s / day
Inclination 4.5102°
Physical characteristics
Dimensions 19.20±0.49 km[3]
21.678±0.046 km[5]
21.91±0.41 km[6]
25.41 km (calculated)[7]
4.5 h (dated)[8]
4.54619±0.00005 h[9]
4.5462±0.0004 h[10]
4.5463±0.0002 h[10]
4.55±0.01 h[11]
0.20 (assumed)[7]
B–V = 0.887[1]
U–B = 0.505[1]
S (Tholen)[1]
S (SMASS)[1]
10.34[1][3][5][6][7] · 10.34±0.28[12]

797 Montana, provisional designation 1914 VR, is a stony asteroid from the middle region of the asteroid belt, approximately 22 kilometers in diameter. It was discovered on 17 November 1914, by Danish astronomer Holger Thiele at Bergedorf Observatory in Hamburg, Germany.[13] It was later named for the discovering observatory.[2]

Classification and orbit[edit]

Montana is a stony asteroid that orbits the Sun in the middle main-belt at a distance of 2.4–2.7 AU once every 4.04 years (1,474 days). Its orbit has an eccentricity of 0.06 and an inclination of 5° with respect to the ecliptic.[1] The first identification at Heidelberg dates back to 1898 (A898 WA / 1898 WA), while the asteroid's observation arc begins two months after its discovery with the first used observation made at Bergedorf in 1915.[13]

Physical characteristics[edit]

In both the Tholen and SMASS taxonomy, Montana is a common stony S-type asteroid.[1]

Rotation period[edit]

Between 2003 and 2007, three rotational lightcurves of Montana were obtained from photometric observations made by amateur astronomers René Roy, Horacio Correia, Laurent Bernasconi, and Richard Ditteon. All three lightcurves gave a well-defined rotation period of 4.55 hours with a brightness variation between 0.32 and 0.41 magnitude (U=3/3/3).[10][11]

Diameter and albedo[edit]

According to the space-based surveys carried out by the Japanese Akari satellite and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Montana's surface has an albedo of 0.28–0.35 and its diameter measures between 19.2 and 21.9 kilometers,[3][4][5][6] while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a somewhat larger diameter of 25.4 kilometers, as the lower the albedo, the larger the body's diameter at a constant absolute magnitude.[7]


This minor planet was named in honor of the Bergedorf Observatory. It was the observatory's first ever made discovery. "Montana" means "mountain village" in Latin and literally translates to "Bergedorf" in German (H 79).[2]


  1. ^ a b c d e f g h i "JPL Small-Body Database Browser: 797 Montana (1914 VR)" (2016-11-09 last obs.). Jet Propulsion Laboratory. Retrieved 12 December 2016. 
  2. ^ a b c Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (797) Montana. Springer Berlin Heidelberg. p. 74. ISBN 978-3-540-00238-3. Retrieved 26 May 2016. 
  3. ^ 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. Bibcode:2012ApJ...759L...8M. arXiv:1209.5794Freely accessible. doi:10.1088/2041-8205/759/1/L8. Retrieved 26 May 2016. 
  4. ^ a b c 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. Bibcode:2014ApJ...791..121M. arXiv:1406.6645Freely accessible. doi:10.1088/0004-637X/791/2/121. Retrieved 12 December 2016. 
  5. ^ 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". The Astrophysical Journal. 741 (2): 25. Bibcode:2011ApJ...741...90M. arXiv:1109.6407Freely accessible. doi:10.1088/0004-637X/741/2/90. Retrieved 26 May 2016. 
  6. ^ 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 26 May 2016. 
  7. ^ a b c d "LCDB Data for (797) Montana". Asteroid Lightcurve Database (LCDB). Retrieved 26 May 2016. 
  8. ^ Angeli, C. A.; Guimarã; es, T. A.; Lazzaro, D.; Duffard, R.; Fernández, S.; et al. (April 2001). "Rotation Periods for Small Main-Belt Asteroids From CCD Photometry". The Astronomical Journal. 121 (4): 2245–2252. Bibcode:2001AJ....121.2245A. doi:10.1086/319936. Retrieved 26 May 2016. 
  9. ^ Hanus, J.; Durech, J.; Oszkiewicz, D. A.; Behrend, R.; Carry, B.; Delbo, M.; et al. (February 2016). "New and updated convex shape models of asteroids based on optical data from a large collaboration network". Astronomy and Astrophysics. 586: 24. Bibcode:2016A&A...586A.108H. arXiv:1510.07422Freely accessible. doi:10.1051/0004-6361/201527441. Retrieved 26 May 2016. 
  10. ^ a b c Behrend, Raoul. "Asteroids and comets rotation curves – (797) Montana". Geneva Observatory. Retrieved 26 May 2016. 
  11. ^ a b Ditteon, Richard; Hirsch, Brian; Kirkpatrick, Elaine; Kramb, Stephen; Kropf, Matthew; Meehl, Joshua; et al. (September 2004). "2003-04 winter observing campaign at Rose-Hulman Institute. Results for 797 Montana, 3227 Hasegawa, 3512 Eriepa, 4159 Freeman, 5234 Sechenov, and (5892) 1981 YS1". The Minor Planet Bulletin. 31 (3): 54–56. Bibcode:2004MPBu...31...54D. ISSN 1052-8091. Retrieved 26 May 2016. 
  12. ^ 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. Bibcode:2015Icar..261...34V. arXiv:1506.00762Freely accessible. doi:10.1016/j.icarus.2015.08.007. Retrieved 26 May 2016. 
  13. ^ a b "797 Montana (1914 VR)". Minor Planet Center. Retrieved 26 May 2016. 

External links[edit]