سیارک ۲۹۷۵

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سیارک ۲۹۷۵
اکتشاف
تاریخ کشف ژانویه ۸, ۱۹۷۰
مبدا مه ۱۴, ۲۰۰۸
خروج از مرکز ۰.۰۹۴۸۷۲۱
آنومالی متوسط ۷۱.۸۸۸۷۵
زاویه انحراف ۶.۸۹۹۵۴
اوج ۲.۴۶۲۲۶۱۲
حضیض ۲.۰۳۵۵۴۴۸
تناوب مداری ۱۲۳۱.۸۴۰۶۱۶۲

سیارک ۲۹۷۵ (به انگلیسی: 2975 Spahr، نامگذاری:1970AF1) دو هزار و نهصد و هفتاد و پنجمین سیارک کشف شده‌است[۱] که در ۸ ژانویه ۱۹۷۰ کشف شد.[۲]

قدر مطلق سیارک برابر ۱۲٫۷۰ است.[۳]

منابع[ویرایش]

  1. طبق اینجا شماره سیارک معرف شماره کشف شدن آنهاست.
  2. «فهرست سیارک‌های شماره‌دار». دانشگاه هاروارد. دریافت‌شده در ۲۸ سپتامبر ۲۰۰۹.
  3. «فهرست داده‌های سیارک‌ها». ناسا. بایگانی‌شده از روی نسخه اصلی در ۱۳ مه ۲۰۱۹. دریافت‌شده در ۱۴ مه ۲۰۱۹.

پیوند به بیرون[ویرایش]


2975 Spahr
Discovery [1]
Discovered byH. Potter
A. Lokalov
Discovery siteCerro El Roble Stn.
Discovery date8 January 1970
Designations
MPC designation(2975) Spahr
Named after
Timothy Spahr[1]
(MPC director)
1970 AF1 · 1957 HU
1967 GH · 1970 AK1
1970 CB · 1978 PF4
main-belt[1][2] · (inner)
background[3][4] · Flora[5]
Orbital characteristics[2]
Epoch 23 March 2018 (JD 2458200.5)
Uncertainty parameter 0
Observation arc61.07 yr (22,304 d)
Aphelion2.4621 AU
Perihelion2.0351 AU
2.2486 AU
Eccentricity0.0949
3.37 yr (1,232 d)
44.830°
0° 17m 32.28s / day
Inclination6.8979°
236.58°
317.02°
Physical characteristics
Mean diameter
5.919±0.107 km[6]
6.032±0.082 km[7]
6.51 km (calculated)[5]
11.946±0.006 h[8]
0.24 (assumed)[5]
0.4044±0.0445[7]
0.419±0.085[6]
S (SDSS-MOC)[9]
S (Pan-STARRS)[5][10]
A (S3OS2-TH)[11]
A (S3OS2-BB)[11]
12.7[7]
13.0[1][2]
13.1[5]
13.81±0.38[10]

2975 Spahr, provisional designation 1970 AF1, is a bright background asteroid from the Flora region of the inner asteroid belt, approximately 6 kilometers (3.7 miles) in diameter. It was discovered on 8 January 1970, by Russian astronomers Hejno Potter and A. Lokalov at the Cerro El Roble Station near Santiago, Chile.[1] The S- or A-type asteroid has a rotation period of 11.9 hours.[5] It was named for Timothy Spahr, an American astronomer and former director of the Minor Planet Center.[12]

Orbit and classification

Spahr is a non-family asteroid of the main belt's background population when applying the hierarchical clustering method to its proper orbital elements.[3][4] Based on osculating Keplerian orbital elements, the asteroid has also been classified as a member of the Flora family (402), a giant asteroid family and the largest family of stony asteroids in the main-belt.[5]

It orbits the Sun in the inner asteroid belt at a distance of 2.0–2.5 AU once every 3 years and 4 months (1,232 days; semi-major axis of 2.25 AU). Its orbit has an eccentricity of 0.09 and an inclination of 7° with respect to the ecliptic.[2]

The asteroid was first observed as 1957 HU at the Johannesburg-Hartbeespoort Observatory (076) on April 1957. The body's observation arc begins as 1967 GH at Crimea-Nauchnij in April 1967, nearly 3 years prior to its official discovery observation at Cerro El Roble.[1]

Physical characteristics

In the SDSS-based taxonomy, Spahr is a stony S-type asteroid.[9] Pan-STARRS' survey also characterizes the body as an S-type,[5][10] while in both, the Tholen- and SMASS-like taxonomy of the Small Solar System Objects Spectroscopic Survey (S3OS2), Spahr is an uncommon A-type asteroid.[4][11]

Rotation period

In December 2009, a first rotational lightcurve of Spahr was obtained from photometric observations by French amateur astronomer René Roy. Lightcurve analysis gave a rotation period of 11.946 hours with a relatively high brightness amplitude of 0.47 magnitude (U=3-).[5][8]

Diameter and albedo

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Spahr measures between 5.919 and 6.032 kilometers in diameter and its surface has a high albedo between 0.4044 and 0.419.[6][7] The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.24 – derived from 8 Flora, the parent body of the Flora family – and consequently calculates a larger diameter of 6.51 kilometers using an absolute magnitude of 13.1.[5]

Naming

This minor planet was named after Timothy Bruce Spahr (born 1970), a discoverer of minor planets and comets such as 171P/Spahr and 242P/Spahr, as well as a co-discoverer of Callirrhoe and Albiorix (moon), satellites of Jupiter and Saturn, respectively. Spahr was with the photographic Bigelow Sky Survey, which searched for high-latitude minor planets using the 0.41-m Catalina Schmidt telescope. (This survey was superseded by the Catalina Sky Survey). Spahr also headed the Minor Planet Center (MPC) form 2000 to 2014.[13] The asteroid's name was proposed by his MPC-colleges Brian Marsden, Gareth Williams and Stephen Larson,[12] and published by the MPC on 3 May 1996 (M.P.C. 27124).[14]

References

  1. ^ a b c d e f "2975 Spahr (1970 AF1)". Minor Planet Center. Retrieved 5 June 2018.
  2. ^ a b c d "JPL Small-Body Database Browser: 2975 Spahr (1970 AF1)" (2018-05-24 last obs.). Jet Propulsion Laboratory. Retrieved 5 June 2018.
  3. ^ a b "Asteroid (2975) Spahr". AstDyS-2, Asteroids – Dynamic Site. Retrieved 5 June 2018.
  4. ^ a b c "Asteroid 2975 Spahr". Small Bodies Data Ferret. Retrieved 5 June 2018.
  5. ^ a b c d e f g h i j "LCDB Data for (2975) Spahr". Asteroid Lightcurve Database (LCDB). Retrieved 5 June 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. Retrieved 5 June 2018.
  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. (catalog)
  8. ^ a b Behrend, Raoul. "Asteroids and comets rotation curves – (2975) Spahr". Geneva Observatory. Retrieved 5 June 2018.
  9. ^ a b Carvano, J. M.; Hasselmann, P. H.; Lazzaro, D.; Mothé-Diniz, T. (February 2010). "SDSS-based taxonomic classification and orbital distribution of main belt asteroids". Astronomy and Astrophysics. 510: 12. Bibcode:2010A&A...510A..43C. doi:10.1051/0004-6361/200913322. Archived from the original on 2 May 2018. Retrieved 5 June 2018.
  10. ^ a b c 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.
  11. ^ a b c 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 5 June 2018.
  12. ^ a b Schmadel, Lutz D. (2007). "(2975) Spahr". Dictionary of Minor Planet Names – (2975) Spahr. Springer Berlin Heidelberg. p. 245. doi:10.1007/978-3-540-29925-7_2976. ISBN 978-3-540-00238-3.
  13. ^ "Tim Spahr of the Minor Planet Center – Planetary Radio". The Planetary Society. Retrieved 5 June 2018.
  14. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 5 June 2018.

External links