4450 Pan

From Wikipedia, the free encyclopedia
Jump to: navigation, search
For the moon of Saturn, see Pan (moon). For other uses, see Pan (disambiguation).
4450 Pan
Discovery [1]
Discovered by C. Shoemaker
E. Shoemaker
Discovery site Palomar Obs.
Discovery date 25 September 1987
MPC designation 4450 Pan
Named after
Pan (Greek deity)[2]
1987 SY · 1937 CA
Apollo · NEO · PHA
Orbital characteristics[1]
Epoch 27 June 2015 (JD 2457200.5)
Uncertainty parameter 0
Observation arc 28.22 yr (10,306 days)
Aphelion 2.2882 AU
Perihelion 0.5964 AU
1.4423 AU
Eccentricity 0.5864
1.73 yr (633 days)
Inclination 5.5197°
Earth MOID 0.0285 AU
Physical characteristics
Dimensions 1.0±0.2 km[3]
1.13 km (calculated)[4]
56.48±0.02 h[5]
60±12 h[a]
3.51±0.02 h[6]
0.20 (assumed)[4]

4450 Pan, provisional designation 1987 SY, is a highly eccentric, contact-binary[7] asteroid, classified as a near-Earth and potentially hazardous object. It belongs to the group of Apollo asteroids and measures about 1.1 kilometers in diameter. It was discovered on 25 September 1987, by American astronomers Eugene and Carolyn Shoemaker at the U.S Palomar Observatory in California.[8]

The stony S-type asteroid orbits the Sun at a distance of 0.6–2.3 AU once every 633 days (1 year and 9 months). Its orbit is tilted by 6 degrees to the plane of the ecliptic and shows an exceptionally high eccentricity of 0.59.[1] In 2013, a photometric light-curve analysis at the U.S. Palmer Divide Station in Colorado rendered a relatively long rotation period of 56.48±0.02 hours with a brightness amplitude of 0.64 in magnitude, superseding two less accurate observations.[5] The asteroid's surface has an assumed albedo of 0.20, which is typical for bodies of stony composition.[4] As an Apollo asteroid, it is an Earth-crosser and has a minimum orbit intersection distance with Earth of 0.0285 AU. In addition, due to its extremely eccentric orbit, it is also a Venus- and Mars-crosser and approaches Mercury within 20 Gm.

The asteroid is a contact binary, composed of two lobes in mutual contact, held together only by their weak gravitational attraction, and typically show a dumbbell-like shape (also see 4769 Castalia).[7] A large number of near-Earth objects are believe to be contact binaries.[9]

The minor planet was named after the Greek god of nature and wild animals, Pan, represented in art as a horned half-man, half goat. He developed from a shepherd god into a hunter, fisherman and warrior, and was worshiped by the citizens of Athens, after he had spread panic through the invading Persian armies in the Battle of Marathon (also see 4356 Marathon). The name Pan has also been given to Saturn XVIII, one of the moons of Saturn.[2]


  1. ^ Pravec (2008) web: rotation period 60±12 hours with a brightness amplitude of 0.6 mag. Summary figures at Collaborative Asteroid Lightcurve Link (CALL) for (4450) Pan
  1. ^ a b c d "JPL Small-Body Database Browser: 4450 Pan (1987 SY)" (2015-12-13 last obs.). Jet Propulsion Laboratory. Retrieved January 2016. 
  2. ^ a b Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (4450) Pan. Springer Berlin Heidelberg. p. 382. ISBN 978-3-540-00238-3. Retrieved January 2016. 
  3. ^ Carbognani, Alberto (September 2008). "Lightcurve Photometry of NEAs 4450 Pan, (170891) 2004 TY16 2002 RC118, and 2007 VD12". The Minor Planet Bulletin 35 (3): 109–110. Bibcode:2008MPBu...35..109C. ISSN 1052-8091. Retrieved January 2016. 
  4. ^ a b c d "LCDB Data for (4450) Pan". Asteroid Lightcurve Database (LCDB). Retrieved January 2016. 
  5. ^ a b Warner, Brian D. (April 2014). "Near-Earth Asteroid Lightcurve Analysis at CS3-Palmer Divide Station: 2013 September-December". The Minor Planet Bulletin 41 (2): 113–124. Bibcode:2014MPBu...41..113W. ISSN 1052-8091. Retrieved January 2016. 
  6. ^ Behrend, Raoul. "Asteroids and comets rotation curves – (4450) Pan". Geneva Observatory. Retrieved January 2016. 
  7. ^ a b Dr. Lance A. M. Benner (2013-11-18). "Binary and Ternary near-Earth Asteroids detected by radar". NASA/JPL Asteroid Radar Research. Retrieved 2014-03-01. 
  8. ^ "4450 Pan (1987 SY)". Minor Planet Center. Retrieved January 2016. 
  9. ^ Michael Busch (2012-03-12). "Near-Earth Asteroids and Radar Speckle Tracking" (PDF). Retrieved January 2016. 

External links[edit]