Open main menu

3225 Hoag, provisional designation 1982 QQ, is a dynamical Hungaria asteroid from the innermost regions of the asteroid belt, approximately 5.5 kilometers (3.4 miles) in diameter. It was discovered on 20 August 1982, by American astronomer couple Carolyn and Eugene Shoemaker at the Palomar Observatory in California.[1] The stony S/L-type asteroid has a short rotation period of 2.37 hours.[3] It was named for American astronomer Arthur Hoag.[1]

3225 Hoag
Discovery [1]
Discovered byC. Shoemaker
E. Shoemaker
Discovery sitePalomar Obs.
Discovery date20 August 1982
MPC designation(3225) Hoag
Named after
Arthur Hoag[1]
(American astronomer)
1982 QQ · 1977 RN7
1977 SY2
main-belt · (inner)[2]
Hungaria[1][3][4] · background[5]
Orbital characteristics[2]
Epoch 23 March 2018 (JD 2458200.5)
Uncertainty parameter 0
Observation arc39.52 yr (14,435 d)
Aphelion1.9791 AU
Perihelion1.7805 AU
1.8798 AU
2.58 yr (941 d)
0° 22m 56.64s / day
Earth MOID0.7960 AU (310.1038 LD)
Physical characteristics
Mean diameter
5.06±0.92 km[6]
5.56 km (calculated)[3]
5.921±0.053 km[7]
6.24±0.06 km[8]
2.3717±0.0002 h[9][a]
2.372±0.0004 h[10]
2.3722±0.0005 h[11]
2.3728±0.0005 h[12]
2.373±0.002 h[13]
2.3737±0.0004 h[14]
2.496±0.001 h[15]
0.3 (assumed)[3]
S/L (S3OS2)[16]
E/S (assumed)[3]
13.135±0.001 (R)[10]


Orbit and classificationEdit

Hoag is a member of the dynamical Hungaria group,[1][3][4] that forms the innermost dense concentration of asteroids in the Solar System.[3] However, it is not a member of the Hungaria family (003), located within the dynamical group, but an asteroid of the background population.[5]

It orbits the Sun in the innermost asteroid belt at a distance of 1.8–2.0 AU once every 2 years and 7 months (941 days; semi-major axis of 1.88 AU). Its orbit has an eccentricity of 0.05 and an inclination of 25° with respect to the ecliptic.[2] The body's observation arc begins with its second of two observations, 1977 RN7 and 1977 SY2, taken at Crimea–Nauchnij September 1977, almost 5 years prior to its official discovery observation at Palomar.[1]

Physical characteristicsEdit

The Small Solar System Objects Spectroscopic Survey (S3OS2) characterized Hoag as a stony S-type and uncommon L-type asteroid in the Tholen- and SMASS-like taxonomy, respectively.[16]

Rotation period and polesEdit

Several rotational lightcurves of Hoag have been obtained from photometric observations since 2007.[9][10][11][12][13][14][15] Best-rated lightcurve by American astronomer Brian Warner at his Palmer Divide Observatory in Colorado, gave a well-defined rotation period of 2.3717 hours with a brightness amplitude of 0.12 magnitude (U=3).[3][9][a]

In 2010, Warner also modeled a lightcurve using the data from his various photometric observations. It gave a concurring sidereal period of 2.37219 hours, as well as two spin axes at (45.0°, 45.0°) and (225.0°, 45.0°) in ecliptic coordinates (λ, β).[11]

Diameter and albedoEdit

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Hoag measures between 5.06 and 6.24 kilometers in diameter and its surface has an albedo between 0.28 and 0.32.[6][7][8] The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.3 – a compromise figure between a stony (0.20) and an E-type (0.40) Hungarian asteroid – and calculates a diameter of 5.56 kilometers based on an absolute magnitude of 13.2.[3]


This minor planet was named after American astronomer Arthur Hoag (1921–1999), a former director of the Lowell Observatory, known for his photometric research, the development of astronomical sites and instruments, and investigations of quasars.[1] In 1950, he discovered a type of ring galaxy known as Hoag's Object. The official naming citation was published by the Minor Planet Center on 27 December 1985 (M.P.C. 10311).[18]


  1. ^ a b Lightcurve plot of 3225 Hoag, Palmer Divide Observatory, B. D. Warner (2007), with a period of 2.3717±0.0002 hours and an amplitude of 0.12±0.01 mag. Data points 180. Quality code is 3. Summary figures at the LCDB.


  1. ^ a b c d e f g h "3225 Hoag (1982 QQ)". Minor Planet Center. Retrieved 5 May 2018.
  2. ^ a b c d "JPL Small-Body Database Browser: 3225 Hoag (1982 QQ)" (2017-03-20 last obs.). Jet Propulsion Laboratory. Retrieved 5 May 2018.
  3. ^ a b c d e f g h i j "LCDB Data for (3225) Hoag". Asteroid Lightcurve Database (LCDB). Retrieved 5 May 2018.
  4. ^ a b c d Spratt, Christopher E. (April 1990). "The Hungaria group of minor planets". Journal of the Royal Astronomical Society of Canada. 84: 123–131. Bibcode:1990JRASC..84..123S. ISSN 0035-872X.
  5. ^ a b "(3225) Hoag – Proper elements". AstDyS-2, Asteroids—Dynamic Site. Retrieved 5 May 2018.
  6. ^ 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:1606.08923. Bibcode:2016AJ....152...63N. doi:10.3847/0004-6256/152/3/63.
  7. ^ 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. arXiv:1109.6407. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. (catalog)
  8. ^ 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:1209.5794. Bibcode:2012ApJ...759L...8M. doi:10.1088/2041-8205/759/1/L8.
  9. ^ a b c Warner, Brian D. (September 2007). "Asteroid Lightcurve Analysis at the Palmer Divide Observatory - December 2006 - March 2007". The Minor Planet Bulletin. 34 (3): 72–77. Bibcode:2007MPBu...34...72W. ISSN 1052-8091.
  10. ^ a b c Waszczak, Adam; Chang, Chan-Kao; Ofek, Eran O.; Laher, Russ; Masci, Frank; Levitan, David; et al. (September 2015). "Asteroid Light Curves from the Palomar Transient Factory Survey: Rotation Periods and Phase Functions from Sparse Photometry". The Astronomical Journal. 150 (3): 35. arXiv:1504.04041. Bibcode:2015AJ....150...75W. doi:10.1088/0004-6256/150/3/75.
  11. ^ a b c Warner, Brian D. (October 2010). "Asteroid Lightcurve Analysis at the Palmer Divide Observatory: 2010 March - June". The Minor Planet Bulletin. 37 (4): 161–165. Bibcode:2010MPBu...37..161W. ISSN 1052-8091.
  12. ^ a b Warner, Brian D. (April 2009). "Asteroid Lightcurve Analysis at the Palmer Divide Observatory: 2008 September-December". The Minor Planet Bulletin. 36 (2): 70–73. Bibcode:2009MPBu...36...70W. ISSN 1052-8091.
  13. ^ a b Warner, Brian D. (October 2015). "Asteroid Lightcurve Analysis at CS3-Palmer Divide Station: 2015 March-June". The Minor Planet Bulletin. 42 (4): 267–276. Bibcode:2015MPBu...42..267W. ISSN 1052-8091.
  14. ^ a b Warner, Brian D. (January 2014). "Asteroid Lightcurve Analysis at CS3-Palmer Divide Station: 2013 June- September". The Minor Planet Bulletin. 41 (1): 27–32. Bibcode:2014MPBu...41...27W. ISSN 1052-8091.
  15. ^ a b Behrend, Raoul. "Asteroids and comets rotation curves – (3225) Hoag". Geneva Observatory. Retrieved 5 May 2018.
  16. ^ a b Lazzaro, D.; Angeli, C. A.; Carvano, J. M.; Mothé-Diniz, T.; Duffard, R.; Florczak, M. (November 2004). "S3OS2: the visible spectroscopic survey of 820 asteroids" (PDF). Icarus. 172 (1): 179–220. Bibcode:2004Icar..172..179L. doi:10.1016/j.icarus.2004.06.006. Retrieved 5 May 2018.
  17. ^ 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:1506.00762. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007.
  18. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 5 May 2018.

External linksEdit