830 Petropolitana (prov. designation: A916 QE or 1916 ZZ) is a bright background asteroid from the outer regions of the asteroid belt. It was discovered on 25 August 1916, by Russian astronomer Grigory Neujmin at the Simeiz Observatory on the Crimean peninsula.[1] The stony S-type asteroid has a long rotation period of 39.0 hours and measures approximately 41 kilometers (25 miles) in diameter. It was named after the Russian city of Saint Petersburg.[2]

830 Petropolitana
Lightcurve-modeled shape of Petropolitana
Discovery[1]
Discovered byG. Neujmin
Discovery siteSimeiz Obs.
Discovery date25 August 1916
Designations
(830) Petropolitana
Pronunciation/pɪˌtrɒpəlɪˈtnə/
Named after
Saint Petersburg
(Russian city)[2]
A916 QE · 1933 RK
1949 KW · A917 YD
1916 ZZ · 1917 Σgb
Orbital characteristics[3]
Epoch 31 May 2020 (JD 2459000.5)
Uncertainty parameter 0
Observation arc103.34 yr (37,745 d)
Aphelion3.4169 AU
Perihelion3.0002 AU
3.2085 AU
Eccentricity0.0649
5.75 yr (2,099 d)
297.36°
0° 10m 17.4s / day
Inclination3.8028°
340.28°
90.940°
Physical characteristics
Mean diameter
39.0±0.5 h[10]
  • (217.0°, 36.0°) (λ11)[5]
  • (34.0°, 41.0°) (λ22)[5]
  • 0.174±0.008[9]
  • 0.216±0.049[7]
  • 0.2382±0.020[6]
9.10[1][3]

Orbit and classification edit

Petropolitana 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 outer asteroid belt at a distance of 3.0–3.4 AU once every 5 years and 9 months (2,099 days; semi-major axis of 3.21 AU). Its orbit has an eccentricity of 0.06 and an inclination of 4° with respect to the ecliptic.[3] The body's observation arc begins at Heidelberg Observatory on 3 September 1916, or nine nights after its official discovery observation at Simeiz.[1]

Naming edit

This minor planet was named by its Latin name "Petropolis", after the Russian city of Saint Petersburg. On the same night, Grigory Neujmin also discovered 829 Academia. Both asteroid were named on the occasion of the 200th anniversary of the founding of the Academy of Sciences in Staint Petersburg. The naming was also mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 82).[2]

Physical characteristics edit

In the Tholen classification, Petropolitana is a stony S-type asteroid,[3][5] which are more common in the inner than in the outer asteroid belt.

Rotation period edit

In March 2005, a rotational lightcurve of Petropolitana was obtained from photometric observations by French amateur astronomer Pierre Antonini. Lightcurve analysis gave a rotation period of 39.0±0.5 hours with a brightness variation of 0.15±0.01 magnitude (U=2).[10]

In 2016, a modeled lightcurve gave a concurring sidereal period of 37.347±0.005 hours using data from a large collaboration of individual observers (such as above). The study also determined two spin axes of (217.0°, 36.0°) and (34.0°, 41.0°) in ecliptic coordinates (λ, β).[11] In 2018, however, an international photometric survey, using archived photometric data from the Geneva Observatory as well from dedicated observations, modeled a far longer period of 169.52±0.06 hours with an amplitude of 0.42±0.05 magnitude (U=2). The survey uses combines convex lightcurve inversion with a non-convex algorithm (SAGE) to derive their periods.[12]

Diameter and albedo edit

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), and the Japanese Akari satellite, Petropolitana measures (41.22±1.6), (41.328±0.131) and (48.47±0.92) kilometers in diameter and its surface has an albedo of (0.2382±0.020), (0.216±0.049) and (0.174±0.008), respectively.[6][7][8][9] Alternative mean-diameters published by the WISE team include (43.41±1.15 km) and (51.355±0.403 km) with corresponding albedos of (0.215±0.019) and (0.1542±0.0389).[5] The Collaborative Asteroid Lightcurve Link, adopts the results obtained by IRAS, that is an albedo of 0.2382 and a diameter of 41.22 kilometers based on an absolute magnitude of 9.10.[13]

Two asteroid occultations of Petropolitana from May 2012 and September 2015, gave a best-fit ellipse dimension of (48.0 km × 48.0 km) and (46.0 km × 46.0 km), respectively.[5] These timed observations are taken when the asteroid passes in front of a distant star.

References edit

  1. ^ a b c d e "830 Petropolitana (A916 QE)". Minor Planet Center. Retrieved 9 March 2020.
  2. ^ a b c Schmadel, Lutz D. (2007). "(830) Petropolitana". Dictionary of Minor Planet Names. Springer Berlin Heidelberg. pp. 76–77. doi:10.1007/978-3-540-29925-7_831. ISBN 978-3-540-00238-3.
  3. ^ a b c d e f g h "JPL Small-Body Database Browser: 830 Petropolitana (A916 QE)" (2020-01-06 last obs.). Jet Propulsion Laboratory. Retrieved 9 March 2020.
  4. ^ a b "Asteroid 830 Petropolitana – Proper Elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 9 March 2020.
  5. ^ a b c d e f g "Asteroid 830 Petropolitana". Small Bodies Data Ferret. Retrieved 9 March 2020.
  6. ^ a b c 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 9 March 2020.
  7. ^ a b c Mainzer, A. K.; Bauer, J. M.; Cutri, R. M.; Grav, T.; Kramer, E. A.; Masiero, J. R.; et al. (June 2016). "NEOWISE Diameters and Albedos V1.0". NASA Planetary Data System: EAR-A-COMPIL-5-NEOWISEDIAM-V1.0. Bibcode:2016PDSS..247.....M. Retrieved 9 March 2020.
  8. ^ a b 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. arXiv:1406.6645. Bibcode:2014ApJ...791..121M. doi:10.1088/0004-637X/791/2/121.
  9. ^ a b c 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. (online, AcuA catalog p. 153)
  10. ^ a b Behrend, Raoul. "Asteroids and comets rotation curves – (830) Petropolitana". Geneva Observatory. Retrieved 9 March 2020.
  11. ^ 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. arXiv:1510.07422. Bibcode:2016A&A...586A.108H. doi:10.1051/0004-6361/201527441.
  12. ^ Marciniak, A.; Bartczak, P.; Müller, T.; Sanabria, J. J.; Alí-Lagoa, V.; Antonini, P.; et al. (February 2018). "Photometric survey, modelling, and scaling of long-period and low-amplitude asteroids". Astronomy and Astrophysics. 610: A7. arXiv:1711.01893. Bibcode:2018A&A...610A...7M. doi:10.1051/0004-6361/201731479. ISSN 0004-6361.
  13. ^ "LCDB Data for (830) Petropolitana". Asteroid Lightcurve Database (LCDB). Retrieved 9 March 2020.

External links edit