5542 Moffatt

5542 Moffatt
Discovery [1]
Discovered byPerth Obs.
Discovery sitePerth Obs.
Discovery date6 August 1978
Designations
(5542) Moffatt
Named after
Ethelwin Moffatt
(Australian philanthropist)
1978 PT4 · 1986 LL
main-belt [1][2] · (middle)
Maria [3][4] · Eunomia [5]
Orbital characteristics [2]
Epoch 23 March 2018 (JD 2458200.5)
Uncertainty parameter 0
Observation arc39.71 yr (14,505 d)
Aphelion3.0022 AU
Perihelion2.1727 AU
2.5874 AU
Eccentricity0.1603
4.16 yr (1,520 d)
128.69°
0° 14m 12.48s / day
Inclination15.877°
116.56°
263.20°
Physical characteristics
8.597±0.183 km[6][7]
10.06 km (calculated)[5]
5.187±0.001 h[8]
5.195 h[4]
0.21 (assumed)[5]
0.345±0.055[6][7]
S (assumed)[5]
12.1[7]
12.3[2][5]
12.67±0.25[9]

5542 Moffatt, provisional designation 1978 PT4, is a Marian asteroid from the central regions of the asteroid belt, approximately 9 kilometers (6 miles) in diameter. It was discovered on 6 August 1978, by astronomers at the Perth Observatory in Bickley, Australia.[1] The likely S-type asteroid has a rotation period of 5.19 hours.[5] It was named for Australian Ethelwin Moffatt, a benefactor of the discovering observatory.[1]

Orbit and classification

Moffatt is a core member of the Maria family (506),[3][4] a large intermediate belt family of stony asteroids.[10] Alternatively, it has also been assigned to the stony Eunomia family (502), one of the most prominent families in the intermediate main belt with more than 5,000 members.[5]

It orbits the Sun in the central main-belt at a distance of 2.2–3.0 AU once every 4 years and 2 months (1,520 days; semi-major axis of 2.59 AU). Its orbit has an eccentricity of 0.16 and an inclination of 16° with respect to the ecliptic.[2] The body's observation arc begins with its first observation at Palomar Observatory in July 1978, a month prior to its official discovery observation at Bickley.[1]

Physical characteristics

Moffatt is an assumed stony S-type asteroid.[5]

Rotation period

In November 2011, a rotational lightcurve of Moffatt was obtained from photometric observations by Chinese astronomers using the SARA telescopes (G82) of the Southeastern Association for Research in Astronomy at Kitt Peak and CTIO. Lightcurve analysis gave a rotation period of 5.187 hours and a brightness variation of 0.12 magnitude (U=2+).[8] This supersedes a previous result from a fragmentary lightcurve by Alvaro Alvarez-Candal that gave a period of 5.195 hours with an amplitude of 0.27 magnitude (U=1).[4]

Diameter and albedo

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Moffatt measures 8.597 kilometers in diameter and its surface has a high albedo of 0.345.[6][7] The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.21 – derived from 15 Eunomia, the parent body of the Eunomia family – and calculates a diameter of 10.06 kilometers based on an absolute magnitude of 12.3.[5]

Naming

This minor planet was named after Australian Ethelwin Moffatt (née Winzar, born 1926), a benefactor of the discovering Perth Observatory and a direct descendant of John Flamsteed (1646–1719), the first Astronomer Royal. The official naming citation was published by the Minor Planet Center on 2 September 2001 (M.P.C. 43380).[11]

References

  1. ^ a b c d e "5542 Moffatt (1978 PT4)". Minor Planet Center. Retrieved 23 May 2018.
  2. ^ a b c d "JPL Small-Body Database Browser: 5542 Moffatt (1978 PT4)" (2018-04-23 last obs.). Jet Propulsion Laboratory. Retrieved 23 May 2018.
  3. ^ a b "Asteroid 5542 Moffatt". Small Bodies Data Ferret. Retrieved 23 May 2018.
  4. ^ a b c d Alvarez-Candal, Alvaro; Duffard, René; Angeli, Cláudia A.; Lazzaro, Daniela; Fernández, Silvia (December 2004). "Rotational lightcurves of asteroids belonging to families". Icarus. 172 (2): 388–401. Bibcode:2004Icar..172..388A. doi:10.1016/j.icarus.2004.06.008.
  5. ^ a b c d e f g h i "LCDB Data for (5542) Moffatt". Asteroid Lightcurve Database (LCDB). Retrieved 23 May 2018.
  6. ^ a b c Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Dailey, J.; et al. (November 2011). "Main Belt Asteroids with WISE/NEOWISE. I. Preliminary Albedos and Diameters". The Astrophysical Journal. 741 (2): 20. arXiv:1109.4096. Bibcode:2011ApJ...741...68M. doi:10.1088/0004-637X/741/2/68. S2CID 118745497.
  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. S2CID 35447010. (catalog)
  8. ^ a b Han, Xianming L.; Li, Bin; Zhao, Haibin; Liu, Wenjuan; Sun, Luming; Shi, Jingjing; et al. (April 2013). "Photometric Observations of 782 Montefiore, 3842 Harlansmith 5542 Moffatt, 6720 Gifu, and (19979) 1989 VJ". The Minor Planet Bulletin. 40 (2): 99–100. Bibcode:2013MPBu...40...99H. ISSN 1052-8091.
  9. ^ 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. S2CID 53493339.
  10. ^ Nesvorný, D.; Broz, M.; Carruba, V. (December 2014). "Identification and Dynamical Properties of Asteroid Families". Asteroids IV. pp. 297–321. arXiv:1502.01628. Bibcode:2015aste.book..297N. doi:10.2458/azu_uapress_9780816532131-ch016. ISBN 9780816532131. S2CID 119280014.
  11. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 23 May 2018.