1400 Tirela

1400 Tirela

Modelled shape of Tirela from its lightcurve
Discovery[1]
Discovered by	L. Boyer
Discovery site	Algiers Obs.
Discovery date	17 November 1936
Designations
MPC designation	(1400) Tirela
Named after	Charles Tirel[2] (discoverer's friend)
Alternative designations	1936 WA · 1930 UQ
Minor planet category	main-belt · (outer)[3] Tirela[4]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	86.96 yr (31,762 days)
Aphelion	3.8513 AU
Perihelion	2.4001 AU
Semi-major axis	3.1257 AU
Eccentricity	0.2322
Orbital period (sidereal)	5.53 yr (2,018 days)
Mean anomaly	316.88°
Mean motion	0° 10^m 42.24^s / day
Inclination	15.631°
Longitude of ascending node	210.10°
Argument of perihelion	111.65°
Physical characteristics
Mean diameter	14.67±0.62 km[5] 15.697±0.285 km[6][7]
Synodic rotation period	13.356 h[8]
Pole ecliptic latitude	(58.0°, −80.0°) (λ1/β1)[4] (297.0°, −41.0°) (λ2/β2)[4]
Geometric albedo	0.216±0.031[6] 0.2165±0.0309[7] 0.227±0.022[5]
Spectral type	C (assumed)[3]
Absolute magnitude (H)	11.3[7] · 11.4[1][3] · 11.50[5]

1400 Tirela (prov. designation: 1936 WA) is an asteroid and the parent body of the Tirela family, located in the outer regions of the asteroid belt. It was discovered on 17 November 1936, by French astronomer Louis Boyer at the Algiers Observatory in North Africa.[9] The asteroid has a rotation period of 13.4 hours and measures approximately 16 kilometers (9.9 miles) in diameter. It was named after Charles Tirel, a friend of the discoverer.[2]

Orbit and classification

Tirela is the parent body of the Tirela family,[4] a fairly large asteroid family, also known as the Klumpkea family, after its largest member 1040 Klumpkea.[10]: 23  It orbits the Sun in the outer main belt at a distance of 2.4–3.9 AU once every 5 years and 6 months (2,018 days). Its orbit has an eccentricity of 0.23 and an inclination of 16° with respect to the ecliptic.[1] The asteroid was first identified as 1930 UQ at Lowell Observatory in October 1930. The body's observation arc also begins at Lowell Observatory, with a precovery taken the night before its first identification.[9]

Naming

This minor planet was named after Charles Tirel a friend of discoverer Louis Boyer-[2] The official naming citation was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 127).[2]

Physical characteristics

In both the Tholen- and SMASS-like taxonomy of the Small Solar System Objects Spectroscopic Survey (S3OS2), Tirela is a dark D-type asteroid.[4][11] Conversely, the overall spectral type of the Tirela family is that of an S-type which agrees with the determined albedo (see below) by WISE and Akari.[10]: 23 

Rotation period and poles

In the early 2000s, a rotational lightcurve of Tirela was obtained from photometric observations by a group of Hungarian astronomers. Lightcurve analysis gave a rotation period of 13.356 hours with a brightness amplitude of 0.55 magnitude (U=2),[8] superseding the result from a previous observation that gave a period of 8 hours.[a] A 2016-published lightcurve, using modeled photometric data from the Lowell Photometric Database, gave a concurring sidereal period of 13.35384±0.00001 hours, as well as two spin axis of (58.0°, −80.0°) and (297.0°, −41.0°) in ecliptic coordinates (λ, β).[12]

Diameter and albedo

According to the surveys carried out by the Japanese Akari satellite and the NEOWISE mission of NASA's WISE telescope, Tirela measures between 14.67 and 15.697 kilometers in diameter and its surface has an albedo between 0.216 and 0.227.[5][6][7] The Collaborative Asteroid Lightcurve Link assumes a standard albedo for carbonaceous asteroids of 0.057 and calculates a diameter of 29.21 kilometers based on an absolute magnitude of 11.4.[3]

Notes

1. Lightcurve (not published) on Behrend website from 2001-07-03: rotation period 8 hours with a brightness amplitude of 0.25 mag. Quality code of 2. Summary figures for (1400) Tirela at LCDB

References

1. "JPL Small-Body Database Browser: 1400 Tirela (1936 WA)" (2017-09-30 last obs.). Jet Propulsion Laboratory. Retrieved 25 October 2017.
2. Schmadel, Lutz D. (2007). "(1400) Tirela". Dictionary of Minor Planet Names. Springer Berlin Heidelberg. p. 113. doi:10.1007/978-3-540-29925-7_1401. ISBN 978-3-540-00238-3.
3. "LCDB Data for (1400) Tirela". Asteroid Lightcurve Database (LCDB). Retrieved 25 October 2017.
4. "Asteroid 1400 Tirela – Nesvorny HCM Asteroid Families V3.0". Small Bodies Data Ferret. Retrieved 26 October 2019.
5. 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)
6. 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. Retrieved 25 October 2017.
7. 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.
8. Székely, P.; Kiss, L. L.; Szabó, Gy. M.; Sárneczky, K.; Csák, B.; Váradi, M.; et al. (August 2005). "CCD photometry of 23 minor planets". Planetary and Space Science. 53 (9): 925–936. arXiv:astro-ph/0504462. Bibcode:2005P&SS...53..925S. doi:10.1016/j.pss.2005.04.006.
9. "1400 Tirela (1936 WA)". Minor Planet Center. Retrieved 25 October 2017.
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 978-0-8165-3213-1.
11. 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 16 March 2020.
12. Durech, J.; Hanus, J.; Oszkiewicz, D.; Vanco, R. (March 2016). "Asteroid models from the Lowell photometric database". Astronomy and Astrophysics. 587: 6. arXiv:1601.02909. Bibcode:2016A&A...587A..48D. doi:10.1051/0004-6361/201527573. Retrieved 25 October 2017.

External links

• Lightcurve Database Query (LCDB), at www.minorplanet.info
• Dictionary of Minor Planet Names, Google books
• Asteroids and comets rotation curves, CdR – Geneva Observatory, Raoul Behrend
• Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
• 1400 Tirela at AstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 1400 Tirela at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters