461 Saskia

461 Saskia

Discovery [1]
Discovered by	M. F. Wolf
Discovery site	Heidelberg Obs.
Discovery date	22 October 1900
Designations
MPC designation	(461) Saskia
Pronunciation	German: [ˈzaski.aː][2]
Named after	Saskia van Uylenburgh [3] (wife of Rembrandt)
Alternative designations	1900 FP · 1935 CT A917 XE · A924 DB
Minor planet category	main-belt [1][4] · (outer) Themis [5][6]
Orbital characteristics [4]
Epoch 23 March 2018 (JD 2458200.5)
Uncertainty parameter 0
Observation arc	117.58 yr (42,946 d)
Aphelion	3.5621 AU
Perihelion	2.6834 AU
Semi-major axis	3.1227 AU
Eccentricity	0.1407
Orbital period (sidereal)	5.52 yr (2,016 d)
Mean anomaly	71.934°
Mean motion	0° 10^m 42.96^s / day
Inclination	1.4634°
Longitude of ascending node	157.03°
Argument of perihelion	305.17°
Physical characteristics
Mean diameter	39.81±13.20 km[7] 43.10±1.05 km[8] 43.603±0.256 km[9][10] 44.1±4.4 km[11]
Synodic rotation period	7.348 h[12][13]
Geometric albedo	0.06[7][11] 0.069[8] 0.112[9]
Spectral type	Tholen = FCX [4][14] X (S3OS2)[5][15] B–V = 0.610±028[4] U–B = 0.310±014[4]
Absolute magnitude (H)	10.48[1][4][8][9][11][16] 10.63[7]

461 Saskia, provisional designation 1900 FP, is a Themistian asteroid from the outer regions of the asteroid belt, approximately 44 kilometers (27 miles) in diameter. It was discovered on 22 October 1900, by German astronomer Max Wolf at the Heidelberg Observatory in southwest Germany.[1] The X-type asteroid has a rotation period of 7.3 hours.[14] It was named after Rembrandt's wife, Saskia van Uylenburgh.[3]

Orbit and classification

Saskia is a core member of the carbonaceous Themis family (602),[5][6] one of the largest asteroid families named after 24 Themis.[17] It orbits the Sun in the outer asteroid belt at a distance of 2.7–3.6 AU once every 5 years and 6 months (2,016 days; semi-major axis of 3.12 AU). Its orbit has an eccentricity of 0.14 and an inclination of 1° with respect to the ecliptic.[4] The body's observation arc begins at Heidelberg the night after its official discovery observation.[1]

Naming

This minor planet was named after Saskia van Uylenburgh (1612–1642), wife of renowned Dutch painter Rembrandt (4511 Rembrandt). The official naming citation was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 50).[3]

Physical characteristics

In the Tholen classification, this asteroid's spectral type is ambiguous, closest to a dark F-type asteroid, and somewhat similar to that of a C- and X-type (FCX),[4] while in both the Tholen- and SMASS-like taxonomy of the Small Solar System Objects Spectroscopic Survey (S3OS2), Saskia is an X-type asteroid.[5][15] It has also been characterized as a primitive P-type asteroid by the Wide-field Infrared Survey Explorer (WISE).[14][16]

Rotation period

In April 2007, a rotational lightcurve of Saskia was obtained from photometric observations by French amateur astronomer Pierre Antonini. Lightcurve analysis gave a well-defined rotation period of 7.348±0.001 hours with a brightness variation of 0.36 magnitude (U=3).[12][14] In December 2016, an identical period with an amplitude of 0.28 magnitude was determined by Daniel Klinglesmith at Etscorn Campus Observatory (719), New Mexico (U=3-).[13] This result supersedes two previous observations that gave a period of 7.34 and 7.349 hours, respectively (U=2/3-).[18][19]

Diameter and albedo

According to the survey carried out by the NEOWISE mission of NASA's WISE telescope, Saskia measures between 39.8 and 44.1 kilometers in diameter and its surface has an albedo between 0.06 and 0.112,[7][9][10][11] while the Japanese Akari satellite determined a diameter of 43.10 kilometers with an albedo of 0.069.[8] The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.10 and derives a smaller diameter of 33.69 kilometers based on an absolute magnitude of 10.48.[14]

References

1. "461 Saskia (1900 FP)". Minor Planet Center. Retrieved 17 July 2018.
2. (German Names)
3. Schmadel, Lutz D. (2007). "(461) Saskia". Dictionary of Minor Planet Names. Springer Berlin Heidelberg. p. 52. doi:10.1007/978-3-540-29925-7_462. ISBN 978-3-540-00238-3.
4. "JPL Small-Body Database Browser: 461 Saskia (1900 FP)" (2018-05-22 last obs.). Jet Propulsion Laboratory. Retrieved 17 July 2018.
5. "Asteroid 461 Saskia". Small Bodies Data Ferret. Retrieved 17 July 2018.
6. "Asteroid (461) Saskia". AstDyS-2, Asteroids – Dynamic Site. Retrieved 25 May 2018.
7. 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.
8. 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. Retrieved 17 July 2018. (online, AcuA catalog p. 153)
9. Mainzer, A. K.; Bauer, J. M.; Cutri, R. M.; Grav, T.; Kramer, E. A.; Masiero, J. R.; et al. (June 2016). "NEOWISE Diameters and Albedos V1.0". NASA Planetary Data System: EAR–A–COMPIL–5–NEOWISEDIAM–V1.0. Bibcode:2016PDSS..247.....M. Retrieved 17 July 2018.
10. Masiero, Joseph R.; Grav, T.; Mainzer, A. K.; Nugent, C. R.; Bauer, J. M.; Stevenson, R.; et al. (August 2014). "Main-belt Asteroids with WISE/NEOWISE: Near-infrared Albedos". The Astrophysical Journal. 791 (2): 11. arXiv:1406.6645. Bibcode:2014ApJ...791..121M. doi:10.1088/0004-637X/791/2/121. S2CID 119293330.
11. 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" (PDF). Astronomy and Astrophysics. 591: 11. Bibcode:2016A&A...591A..14A. doi:10.1051/0004-6361/201527660.
12. Behrend, Raoul. "Asteroids and comets rotation curves – (461) Saskia". Geneva Observatory. Retrieved 17 July 2018.
13. Klinglesmith, Daniel A., III (April 2017). "Spin-Shape Model Lightcurves". The Minor Planet Bulletin. 44 (2): 127–129. Bibcode:2017MPBu...44..127K. ISSN 1052-8091.
14. "LCDB Data for (461) Saskia". Asteroid Lightcurve Database (LCDB). Retrieved 17 July 2018.
15. 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 17 July 2018.
16. 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)
17. 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 978-0-8165-3213-1. S2CID 119280014.
18. Buchheim, Robert K. (September 2006). "Lightcurves of asteroids 125 Liberatrix, 461 Saskia, and 2781 Kleczek". The Minor Planet Bulletin. 33 (3): 63. Bibcode:2006MPBu...33...63B. ISSN 1052-8091.
19. Klinglesmith, Daniel A. III; Hanowell, Jesse; Risley, Ethan; Turk, Janek; Vargas, Angelica; Warren, Curtis Alan (October 2013). "Inversion Model Candidates". The Minor Planet Bulletin. 40 (4): 190–193. Bibcode:2013MPBu...40..190K. ISSN 1052-8091.

External links

• Asteroid Lightcurve Database (LCDB), query form (info Archived 16 December 2017 at the Wayback Machine)
• Dictionary of Minor Planet Names, Google books
• Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
• Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
• 461 Saskia at AstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 461 Saskia at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters