1082 Pirola

1082 Pirola

Modelled shape of Pirola from its lightcurve
Discovery[1]
Discovered by	K. Reinmuth
Discovery site	Heidelberg Obs.
Discovery date	28 October 1927
Designations
MPC designation	(1082) Pirola
Pronunciation	/ˈpɪrələ/[2]
Named after	Pyrola (wintergreen) (herbaceous plant)[3]
Alternative designations	1927 UC · 1931 JQ 1951 AH · 1952 DS 1971 YJ · A916 UP
Minor planet category	main-belt[1][4] · (outer) Themis[5][6][7]
Orbital characteristics[4]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	90.01 yr (32,875 days)
Aphelion	3.6858 AU
Perihelion	2.5553 AU
Semi-major axis	3.1205 AU
Eccentricity	0.1811
Orbital period (sidereal)	5.51 yr (2,013 days)
Mean anomaly	130.74°
Mean motion	0° 10^m 43.68^s / day
Inclination	1.8524°
Longitude of ascending node	148.01°
Argument of perihelion	187.23°
Physical characteristics
Mean diameter	37.363±1.036 km[8] 39.14±13.91 km[9] 41.47±12.07 km[10] 42.607±0.476 km[11] 42.61±0.48 km[11] 44.67±0.71 km[12]
Synodic rotation period	15.85±0.01 h[13] 15.851±0.0140 h[14] 15.8525±0.0005 h[15] 15.8540±0.0001 h[16]
Pole ecliptic latitude	(123.0°, −42.0°) (λ1/β1)[6] (300.0°, −38.0°) (λ2/β2)[6]
Geometric albedo	0.052±0.006[17] 0.06±0.05[9][10] 0.061±0.002[12] 0.067±0.008[11] 0.0867±0.0105[8]
Spectral type	Tholen = C[4][5] B–V = 0.705[4] U–B = 0.315[4]
Absolute magnitude (H)	10.4[1][4][8][9][11][12] · 10.450±0.002 (R)[14] · 10.507±0.014[15] · 10.51[5] · 10.53[10]

1082 Pirola /ˈpɪrələ/ is a dark Themistian asteroid from the outer regions of the asteroid belt. It was discovered on 28 October 1927, by German astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory in Germany, and assigned the provisional designation 1927 UC.[1] The carbonaceous C-type asteroid has a rotation period of 15.9 hours and measures approximately 41 kilometers (25 miles) in diameter. It was named after the herbaceous plant Pyrola (wintergreen).[3]

Orbit and classification

When applying the hierarchical clustering method to its proper orbital elements, Pirola is a Themistian asteroid that belongs to the Themis family (602),[18][6][7] a large family of nearly 6,000 known carbonaceous asteroids, named after 24 Themis.[19]: 23  It orbits the Sun in the outer main belt at a distance of 2.6–3.7 AU once every 5 years and 6 months (2,013 days; semi-major axis of 3.12 AU). Its orbit has an eccentricity of 0.18 and an inclination of 2° with respect to the ecliptic.[4] The asteroid was first identified as A916 UP at Simeiz Observatory in October 1916. The body's observation arc begins with its official discovery observation at Heidelberg in October 1927.[1]

Naming

This minor planet was named after Pyrola, also known as wintergreen, a herbaceous plant (mostly evergreen), that belongs to the flowering herbs. The official naming citation was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 102).[3]

Reinmuth's flowers

Karl Reinmuth submitted a large list of 66 newly named asteroids in the early 1930s. The list covered his discoveries with numbers between (1009) and (1200). This list also contained a sequence of 28 asteroids, starting with 1054 Forsytia, that were all named after plants, in particular flowering plants (also see list of minor planets named after animals and plants).[20] (Unusually the Pirola has lent its name to a COVID-19 variant: BA.2.86.[21])

Physical characteristics

In the Tholen classification, Pirola is a carbonaceous C-type asteroid,[4][5] which matches the overall spectral type of the Themis family.[19]: 23 

Rotation period

In 2010, three rotational lightcurves of Pirola were obtained from photometric observations. Lightcurve analysis gave a rotation period of 15.85, 15.851 and 15.8525 hours with a brightness amplitude between 0.53 and 0.62 magnitude (U=3-/2/3).[13][14][15]

A 2016-published lightcurve, using modeled photometric data from the Lowell Photometric Database, gave a concurring period of 15.8540 hours, as well as two spin axis of (123.0°, −42.0°) and (300.0°, −38.0°) in ecliptic coordinates (λ, β).[16]

Diameter and albedo

According to the surveys carried out by the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Pirola measures between 37.363 and 44.67 kilometers in diameter and its surface has an albedo between 0.052 and 0.0867.[8][9][10][11][12][17] The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0655 and a diameter of 41.06 kilometers based on an absolute magnitude of 10.51.[5]

References

1. "1082 Pirola (1927 UC)". Minor Planet Center. Retrieved 28 November 2017.
2. "pyrola, pirola". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)
3. Schmadel, Lutz D. (2007). "(1082) Pirola". Dictionary of Minor Planet Names. Springer Berlin Heidelberg. p. 92. doi:10.1007/978-3-540-29925-7_1083. ISBN 978-3-540-00238-3.
4. "JPL Small-Body Database Browser: 1082 Pirola (1927 UC)" (2017-10-30 last obs.). Jet Propulsion Laboratory. Retrieved 28 November 2017.
5. "LCDB Data for (1082) Pirola". Asteroid Lightcurve Database (LCDB). Retrieved 28 November 2017.
6. "Asteroid 1082 Pirola – Nesvorny HCM Asteroid Families V3.0". Small Bodies Data Ferret. Retrieved 26 October 2019.
7. Zappalà, V.; Bendjoya, Ph.; Cellino, A.; Farinella, P.; Froeschle, C. (1997). "Asteroid Dynamical Families". NASA Planetary Data System: EAR-A-5-DDR-FAMILY-V4.1. Retrieved 4 March 2020.} (PDS main page)
8. 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.
9. Nugent, C. R.; Mainzer, A.; Masiero, J.; Bauer, J.; Cutri, R. M.; Grav, T.; et al. (December 2015). "NEOWISE Reactivation Mission Year One: Preliminary Asteroid Diameters and Albedos". The Astrophysical Journal. 814 (2): 13. arXiv:1509.02522. Bibcode:2015ApJ...814..117N. doi:10.1088/0004-637X/814/2/117.
10. 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.
11. 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.
12. 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)
13. Gartrelle, Gordon M. (April 2012). "Lightcurve Results for Eleven Asteroids". The Minor Planet Bulletin. 39 (2): 40%–46. Bibcode:2012MPBu...39...40G. ISSN 1052-8091.
14. 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.
15. Baker, Ronald E.; Pilcher, Frederick; Benishek, Vladimir (April 2011). "Photometric Observations and Analysis of 1082 Pirola". The Minor Planet Bulletin. 38 (2): 111–114. Bibcode:2011MPBu...38..111B. ISSN 1052-8091.
16. 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.
17. 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.
18. "Asteroid 1082 Pirola – Proper Elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 13 March 2020.
19. 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.
20. Schmadel, Lutz D. (2007). "(1054) Forsytia". Dictionary of Minor Planet Names. Springer Berlin Heidelberg. p. 90. doi:10.1007/978-3-540-29925-7_1055. ISBN 978-3-540-00238-3.
21. "What we know about the new COVID strain nicknamed after an asteroid". 19 August 2023 – via www.abc.net.au.

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
• 1082 Pirola at AstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 1082 Pirola at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters