Astronomy:762 Pulcova

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762 Pulcova
762Pulcova-SwRI.gif
762 Pulcova and satellite as seen with adaptive optics in 2000[1]
Discovery[2]
Discovered byG. N. Neujmin
Discovery date3 September 1913
Designations
(762) Pulcova
Pronunciation/ˈpʊlkəvə/
Named afterPulkovo Heights
1913 SQ
Minor planet categoryMain belt
AdjectivesPulcovian /pʊlˈkviən/[3]
Orbital characteristics[2]
Epoch 31 July 2016 (JD 2457600.5)
Uncertainty parameter 0
Observation arc100.08 yr (36553 d)
|{{{apsis}}}|helion}}3.4801 astronomical unit|AU (520.62 Gm) (Q)
|{{{apsis}}}|helion}}2.8291 AU (423.23 Gm) (q)
3.1546 AU (471.92 Gm) (a)
Eccentricity0.10319 (e)
Orbital period5.60 yr (2046.5 d)
Mean anomaly348.62° (M)
Mean motion0° 10m 33.276s / day (n)
Inclination13.089° (i)
Longitude of ascending node305.76° (Ω)
189.54° (ω)
Known satellitesS/2000 (762) 1[1]
Earth MOID1.84297 AU (275.704 Gm)
Jupiter MOID1.60162 AU (239.599 Gm)
TJupiter3.158
Physical characteristics
Mean radius68.54±1.6 km
Mass1.40×1018 kg[4]
Mean density0.90 g/cm3[4]
Rotation period5.839 h (0.2433 d)
Sidereal rotation period5.839 hr[2]
Geometric albedo0.0458±0.002[2]
Apparent magnitude11.93 to 14.79[5]
Absolute magnitude (H)8.28[2]


762 Pulcova is a main-belt asteroid. It was discovered by Grigoriy N. Neujmin in 1913,[2] and is named after Pulkovo Observatory, near Saint Petersburg. Pulcova is 137 km in diameter,[2] and is a C-type asteroid, which means that it is dark in colouring with a carbonate composition.

Photometric observations of this asteroid from Leura, Australia during 2006 gave a light curve with a period of 5.8403 ± 0.0005 hours and a brightness variation of 0.20 ± 0.02 in magnitude. This result is in agreement with previous studies.[6]

Satellite

Pulcova and its satellite imaged by the Hubble Space Telescope in January 2005
Diagram of 762 Pulcova's orbit

On February 22, 2000,[1] astronomers at the Canada-France-Hawaii Telescope on Mauna Kea, Hawaii, discovered a 15-km moon (roughly a tenth the size of the primary)[7] orbiting Pulcova at a distance of 800 km.[8] Its orbital period is 4 days.[9] The satellite is about 4 magnitudes fainter than the primary.[8] It was one of the first asteroid moons to be identified.

Density

In the year 2000, Merline estimated Pulcova to have a density of 1.8 g/cm3, which would make it more dense than the trinary asteroid 45 Eugenia, and binary 90 Antiope.[8] But estimates by Marchis in 2008 suggest a density of only 0.90 g/cm3,[4] suggesting it may be a loosely packed rubble pile, not a monolithic object.

References

  1. 1.0 1.1 1.2 "762 Pulcova". SwRI. 2000-02-22. http://www.boulder.swri.edu/merline/press/fig3.html.  (AO image)
  2. 2.0 2.1 2.2 2.3 2.4 2.5 2.6 "JPL Small-Body Database Browser: 762 Pulcova (1913 SQ)". https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=762. 
  3. Catalogue of the Mathematical, Historical, Bibliographical and Miscellaneous Portion of the Celebrated Library of M. Guglielmo Libri, 1861, p. 216
  4. 4.0 4.1 4.2 Jim Baer (2008). "Recent Asteroid Mass Determinations". Personal Website. http://home.earthlink.net/~jimbaer1/astmass.txt. 
  5. Magnitudes generated with JPL Horizons for the year 1950 through 2100
  6. Oey, Julian (December 2006), "Lightcurves analysis of 10 asteroids from Leura Observatory", The Minor Planet Bulletin 33 (4): 96–99, Bibcode2006MPBu...33...96O. 
  7. Dr. William J. Merline; Maria Martinez (2000-10-26). "Astronomers Image Double Asteroid". SwRI Press Release. http://www.boulder.swri.edu/merline/press/release.txt.  (mentions both 90 Antiope and 762 Pulcova)
  8. 8.0 8.1 8.2 W.J. Merline (SwRI); L.M. Close (ESO, U. Arizona) (2000-06-21). "Discovery of Companions to Asteroids 762 Pulcova and 90 Antiope by Direct Imaging". SwRI. http://www.boulder.swri.edu/merline/press/dps.abstract.pdf. 
  9. Johnston, Robert (September 1, 2005). "(762) Pulcova". Johnston's Archive. http://www.johnstonsarchive.net/astro/astmoons/am-00762.html. 

External links