468 Lina, provisional designation 1901 FZ, is a dark Themistian asteroid from the outer region of the asteroid belt, approximately 60 kilometers (37 miles) in diameter. It was discovered on 18 January 1901, by German astronomer Max Wolf at the Heidelberg Observatory in southwest Germany.[17] The carbonaceous asteroid was named for the housemaid of the discoverer's family.[3]

468 Lina
Discovery[1]
Discovered byM. F. Wolf
Discovery siteHeidelberg Obs.
Discovery date18 January 1901
Designations
(468) Lina
PronunciationGerman: [ˈliːnaː][2]
Named after
(household employee)[3]
1901 FZ · A915 PA
A918 EB
main-belt · Themis[4]
Orbital characteristics[1]
Epoch 16 February 2017 (JD 2457800.5)
Uncertainty parameter 0
Observation arc115.81 yr (42,300 days)
Aphelion3.7509 AU
Perihelion2.5136 AU
3.1323 AU
Eccentricity0.1975
5.54 yr (2,025 days)
64.042°
0° 10m 40.08s / day
Inclination0.4371°
21.472°
333.20°
Physical characteristics
Dimensions58.60±14.75 km[5]
59.7±0.5 km[6][7]
59.80±0.89 km[8]
60.238±0.518 km[9]
63.4±12.7 km[10]
64.592±1.981 km[11]
66±7 km[12]
69.34±2.5 km (IRAS:6)[13]
16.33±0.02 h[14]
16.478±0.004 h[15]
16.54±0.01 h[15]
0.0430±0.003 (IRAS:6)[13]
0.0495±0.0094[11]
0.05±0.01[12]
0.05±0.02[10]
0.057±0.009[9]
0.058[6]
0.059±0.002[8]
0.06±0.01[7]
0.06±0.06[5]
Tholen = CPF[1] · P[11] · CPF[4]
B–V = 0.660[1]
U–B = 0.313[1]
9.61[7] · 9.70±0.25[16] · 9.77[5] · 9.83[1][4][6][8][9][10][11][12][13]

Classification and orbit

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Lina is a core member of the Themis family, an ancient population of carbonaceous outer-belt asteroids with nearly coplanar ecliptical orbits. It orbits the Sun at a distance of 2.5–3.8 AU once every 5 years and 6 months (2,025 days). Its orbit has an eccentricity of 0.20 and an inclination of 0.4° with respect to the ecliptic.[1] Lina was first observed at Heidelberg a few days prior to its official discovery observation. The body's observation arc begins with its identification as 1915 PA at Heidelberg in 1915, or 14 years after its official discovery observation.[17]

Naming

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This minor planet was named for "Lina", a domestic housemaid of the discoverer's family at Heidelberg.[3] The members of Max Wolf's household figure prominently in the names of his discoveries, but background information on the name's origin behind most of them have been lost. Wolf also named 482 Petrina and 483 Seppina after the household's two dogs, a practice that was later discouraged by the IAU.[18] Naming citation for Lina was first mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 51).[3]

Physical characteristics

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It has been characterized as a CPF-type and P-type asteroid by Tholen and NEOWISE, respectively.[1][11]

Photometry

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In December 2006, a rotational lightcurve of Lina was obtained by American astronomer Robert Buchheim at Altimira Observatory (G76) in California. Light-curve analysis gave a rotation period of 16.33 hours with a brightness variation of 0.15 magnitude (U=3).[14] Its odd light curve shows multiple peaks, contrary to the classically shaped double-peaks seen in bimodal light curves, that have two maximums and two minimums per rotation. Lina's unusual triple-peak shape made it difficult to fit a period.[14]

Other photometric observations were taken by Edward Tedesco in the 1970s (8.3 hours; Δ mag; U=1),[4] by Pierre Antonini and Raoul Behrend in January 2006 (16.478 hours; Δ0.18 mag; U=2),[15] and by Scott Marks and Michael Fauerbach in February 2007 (16.54 hours; Δ0.13 mag; U=2).[15]

Diameter and albedo

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According to the space-based surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, the Spitzer Space Telescope, and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Lina measures between 58.60 and 69.34 kilometers in diameter, and its surface has an albedo between 0.043 and 0.06.[5][7][8][10][13]

The Collaborative Asteroid Lightcurve Link still adopts the results obtained by IRAS, that is an albedo of 0.043 and a diameter of 69.34 kilometers at an absolute magnitude of 9.83,[4] while more recent results by NEOWISE and Spitzer tend toward a higher albedo of 0.06 and a shorter diameter of 58.60 and 59.7 kilometer, respectively.[5][7] Spitzer's spectra of Lina shows an emissivity plateau in the wavelength range of 9 to 12 μm, which is indicative of silicates.[6]

References

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  1. ^ a b c d e f g h "JPL Small-Body Database Browser: 468 Lina (1901 FZ)" (2016-11-11 last obs.). Jet Propulsion Laboratory. Retrieved 20 January 2017.
  2. ^ (German Names)
  3. ^ a b c d Schmadel, Lutz D. (2007). "(468) Lina". Dictionary of Minor Planet Names – (468) Lina. Springer Berlin Heidelberg. p. 52. doi:10.1007/978-3-540-29925-7_469. ISBN 978-3-540-00238-3.
  4. ^ a b c d e "LCDB Data for (468) Lina". Asteroid Lightcurve Database (LCDB). Retrieved 20 January 2017.
  5. ^ a b c d e 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.
  6. ^ a b c d Licandro, J.; Hargrove, K.; Kelley, M.; Campins, H.; Ziffer, J.; Alí-Lagoa, V.; et al. (January 2012). "5-14 mum Spitzer spectra of Themis family asteroids". Astronomy and Astrophysics. 537: 7. Bibcode:2012A&A...537A..73L. doi:10.1051/0004-6361/201118142.
  7. ^ a b c d e Landsman, Zoe A.; Licandro, Javier; Campins, Humberto; Ziffer, Julie; Prá, Mario de; Cruikshank, Dale P. (May 2016). "The Veritas and Themis asteroid families: 5-14 mum spectra with the Spitzer Space Telescope". Icarus. 269: 62–74. Bibcode:2016Icar..269...62L. doi:10.1016/j.icarus.2016.01.008.
  8. ^ a b c d 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)
  9. ^ a b c 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. S2CID 46350317.
  10. ^ a b c d Alí-Lagoa, V.; Licandro, J.; Gil-Hutton, R.; Cañ; ada-Assandri, M.; Delbo', M.; et al. (June 2016). "Differences between the Pallas collisional family and similarly sized B-type asteroids". Astronomy and Astrophysics. 591: 11. Bibcode:2016A&A...591A..14A. doi:10.1051/0004-6361/201527660. hdl:11336/63614.
  11. ^ a b c d e 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.
  12. ^ a b c Alí-Lagoa, V.; de León, J.; Licandro, J.; Delbó, M.; Campins, H.; Pinilla-Alonso, N.; et al. (June 2013). "Physical properties of B-type asteroids from WISE data". Astronomy and Astrophysics. 554: 16. arXiv:1303.5487. Bibcode:2013A&A...554A..71A. doi:10.1051/0004-6361/201220680. S2CID 119214002.
  13. ^ a b c d 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 22 October 2019.
  14. ^ a b c Buchheim, Robert K. (September 2007). "Lightcurves of 25 Phocaea, 468 Lina, 482 Petrina 551 Ortrud, 741 Botolphia, 834 Burnhamia, 2839 Annette, and 3411 Debetencourt". The Minor Planet Bulletin. 34 (3): 68–71. Bibcode:2007MPBu...34...68B. ISSN 1052-8091.
  15. ^ a b c d Behrend, Raoul. "Asteroids and comets rotation curves – (468) Lina". Geneva Observatory. Retrieved 20 January 2017.
  16. ^ 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.
  17. ^ a b "468 Lina (1901 FZ)". Minor Planet Center. Retrieved 20 January 2017.
  18. ^ Murdin, Paul (2012). Rock Legends: The Asteroids and Their Discoverers – (468) Lina. Springer. p. 112. ISBN 978-3-319-31836-3. Retrieved 20 January 2017.
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