(1026) Ingrid

1026 Ingrid
Discovered byK. Reinmuth
Discovery siteHeidelberg Obs.
Discovery date13 August 1923
(1026) Ingrid
Named after
Ingrid, niece of astronomer Albrecht Kahrstedt[2]
1923 NY · 1957 UC
1963 GD · 1981 WL8
1986 CG2 · 1986 ES2
main-belt · (inner)
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc93.89 yr (34,294 days)
Aphelion2.6636 AU
Perihelion1.8458 AU
2.2547 AU
3.39 yr (1,237 days)
0° 17m 27.96s / day
Physical characteristics
Dimensions5.73±1.01 km[5]
6.96±0.68 km[6]
7.353±0.082 km[7]
7.670±0.069 km[8]
8.19 km (calculated)[3]
5 h[9]
0.24 (assumed)[3]
12.6[3] · 12.70[5] · 12.8[1] · 13.30[6][8]

1026 Ingrid, provisional designation 1923 NY, is a stony Florian asteroid and long-lost minor planet (1923–1986) from the inner regions of the asteroid belt, approximately 7 kilometers in diameter. It was discovered by Karl Reinmuth at Heidelberg in 1923, and later named after Ingrid, niece and godchild of astronomer Albrecht Kahrstedt.[10]

Discovery and recovery[]

Ingrid was discovered on 13 August 1923, by German astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory in southwest Germany. The asteroid was observed for only a few days during August 1923, before it became a lost minor planet for nearly 63 years until its recovery by Japanese astronomer Syuichi Nakano in 1986.[10][11]

Nakano was able to show that Ingrid had been observed and provisionally designated several times during its lost period: as 1957 UC at the discovering Heidelberg Observatory in October 1957, possibly as 1963 GD at Goethe Link Observatory in April 1963, as 1981 WL8 at the Crimean Astrophysical Observatory in November 1981, and as 1986 ES2 at Palomar Observatory in March 1986.[10][11]

With the recovery of Ingrid in 1986, and the almost simultaneously recovered asteroid 1179 Mally, the list of long-lost numbered asteroids was reduced to four.[11] The last remaining lost asteroid, 69230 Hermes, was recovered in 2003.

Orbit and classification[]

Ingrid is a member of the Flora family (402), a giant asteroid family and the largest family of stony asteroids.[3][4] It orbits the Sun in the inner main-belt at a distance of 1.8–2.7 AU once every 3 years and 5 months (1,237 days). Its orbit has an eccentricity of 0.18 and an inclination of 5° with respect to the ecliptic.[1] The body's observation arc begins at Heidelberg, one night after its official discovery observation in 1923.[10]

Physical characteristics[]

Ingrid is an assumed S-type asteroid, in-line with the Flora family's spectral type.[3][12]: 23 

Rotation period[]

A rotational lightcurve of Ingrid was obtained from photometric observations by a group of Hungarian astronomers. The 2005-published lightcurve analysis gave a rotation period of 5 hours with a brightness variation of 0.5 magnitude (U=2).[9]

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, Ingrid measures between 5.73 and 7.67 kilometers in diameter and its surface has an albedo between 0.1441 and 0.43.[5][6][7][8]

The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.24 – derived from 8 Flora, the largest member and namesake of the Flora family – and calculates a diameter of 8.19 kilometers based an absolute magnitude of 12.6.[3]


This minor planet was named after Ingrid, niece and godchild of Albrecht Kahrstedt (1897–1971), a German astronomer at ARI and director of the institute's Potsdam division, who requested the naming of this asteroid and 984 Gretia (mother of Ingrid) in a personal letter to the discoverer in February 1926.[2] Kahrstedt himself was honored with the naming of 1587 Kahrstedt.

The official naming citation was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H98). Lutz Schmadel quoted an excerpt of Kahrstedt's letter in his Dictionary of Minor Planet Names (LDS).[2]


  1. ^ a b c d "JPL Small-Body Database Browser: 1026 Ingrid (1923 NY)" (2017-07-05 last obs.). Jet Propulsion Laboratory. Retrieved 25 August 2017.
  2. ^ a b c Schmadel, Lutz D. (2007). "(1026) Ingrid". Dictionary of Minor Planet Names – (1026) Ingrid. Springer Berlin Heidelberg. p. 88. doi:10.1007/978-3-540-29925-7_1027. ISBN 978-3-540-00238-3.
  3. ^ a b c d e f g h "LCDB Data for (1026) Ingrid". Asteroid Lightcurve Database (LCDB). Retrieved 25 August 2017.
  4. ^ a b "Asteroid 1026 Ingrid – Nesvorny HCM Asteroid Families V3.0". Small Bodies Data Ferret. Retrieved 31 October 2019.
  5. ^ a b c d 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. Retrieved 25 August 2017.
  6. ^ 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)
  7. ^ a b c 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. Retrieved 25 August 2017.
  8. ^ 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.
  9. ^ a b 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. Retrieved 25 August 2017.
  10. ^ a b c d "1026 Ingrid (1923 NY)". Minor Planet Center. Retrieved 25 August 2017.
  11. ^ a b c Brian G. Marsden (8 December 1986). "International Astronomical Union Circular 4281". Central Bureau for Astronomical Telegrams. Retrieved 25 August 2017.
  12. ^ 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.

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