25924 Douglasadams

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25924 Douglasadams
Discovery [1]
Discovered byLINEAR
Discovery siteLincoln Lab's ETS
Discovery date19 February 2001
(25924) Douglasadams
Named after
Douglas Adams
(English author)[2]
2001 DA42 · 1999 VX149
main-belt · (inner)
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc20.30 yr (7,415 days)
Aphelion2.8155 AU
Perihelion2.0147 AU
2.4151 AU
3.75 yr (1,371 days)
0° 15m 45.36s / day
Physical characteristics
Dimensions2.410±0.528 km[4]

25924 Douglasadams, provisional designation 2001 DA42, is a Nysian asteroid from the inner regions of the asteroid belt, approximately 2.4 kilometers in diameter. It was discovered on 19 February 2001, by astronomers of the Lincoln Near-Earth Asteroid Research at the Lincoln Laboratory's Experimental Test Site in New Mexico, United States. The asteroid was named for novelist Douglas Adams.[5]

Orbit and classification[edit]

Douglasadams is a member of the Nysa family (405),[3] better described as the Nysa–Polana complex, as it contains at least three asteroid families with distinct spectral types (SFC).[6]: 23  It orbits the Sun in the inner main-belt at a distance of 2.0–2.8 AU once every 3 years and 9 months (1,371 days). Its orbit has an eccentricity of 0.17 and an inclination of 2° with respect to the ecliptic.[1]

The body's observation arc begins with a precovery taken by Spacewatch at Kitt Peak Observatory in January 1997, more than four years prior to its official discovery observation at Lincoln Lab's ETS.[5]

Physical characteristics[edit]

The spectral type of Douglasadams is unknown. Based on its albedo (see below) it is likely a common stony S-type asteroid.[1]

Diameter and albedo[edit]

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Douglasadams measures 2.410 kilometers in diameter and its surface has an albedo of 0.210.[4] It has an absolute magnitude of 15.6.[1]

Rotation period[edit]

As of 2017, no rotational lightcurve of Douglasadams has been obtained from photometric observations. The asteroid's rotation period, poles and shape remain unknown.[7]


This minor planet was named in memory of English novelist Douglas Adams (1952–2001), because its provisional designation 2001 DA42 happened to contain the year of his death, his initials, and the Answer to the Ultimate Question of Life, the Universe, and Everything (42), as given in his novel serial The Hitchhiker's Guide to the Galaxy.[2] The official naming citation was published by the Minor Planet Center on 25 January 2005 (M.P.C. 53471).[8]

The asteroid 18610 Arthurdent, discovered by Felix Hormuth in 1998, was named after the bewildered hero of Douglas Adams's The Hitchhiker's Guide to the Galaxy.


  1. ^ a b c d e f "JPL Small-Body Database Browser: 25924 Douglasadams (2001 DA42)" (2017-04-29 last obs.). Jet Propulsion Laboratory. Retrieved 24 September 2017.
  2. ^ a b Schmadel, Lutz D. (2006). "(25924) Douglasadams [2.42, 0.17, 1.7]". Dictionary of Minor Planet Names – (25924) Douglasadams, Addendum to Fifth Edition: 2003–2005. Springer Berlin Heidelberg. p. 189. doi:10.1007/978-3-540-34361-5_2211. ISBN 978-3-540-34361-5.
  3. ^ a b "Asteroid 25924 Douglasadams – Nesvorny HCM Asteroid Families V3.0". Small Bodies Data Ferret. Retrieved 27 October 2019.
  4. ^ 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 24 September 2017.
  5. ^ a b "25924 Douglasadams (2001 DA42)". Minor Planet Center. Retrieved 24 September 2017.
  6. ^ 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.
  7. ^ "LCDB Data for (25924) Douglasadams". Asteroid Lightcurve Database (LCDB). Retrieved 24 September 2017.
  8. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 24 September 2017.

External links[edit]