| Discovery[1] | |
|---|---|
| Discovered by | K. Reinmuth |
| Discovery site | Heidelberg Obs. |
| Discovery date | 10 March 1920 |
| Designations | |
| (929) Algunde | |
Named after | Name picked from the almanac Lahrer Hinkender Bote[2] |
| A920 ED · 1920 GR | |
| Orbital characteristics[3] | |
| Epoch 31 May 2020 (JD 2459000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 99.82yr (36,460 d) |
| Aphelion | 2.4921AU |
| Perihelion | 1.9859 AU |
| 2.2390 AU | |
| Eccentricity | 0.1131 |
| 3.35 yr (1,224 d) | |
| 249.25° | |
| 0° 17m 39.12s / day | |
| Inclination | 3.9128° |
| 231.38° | |
| 22.990° | |
| Physical characteristics | |
| 3.31016±0.00009 h[9][10] | |
| 11.7[1][3] | |
929 Algunde (prov. designation:A920 EDor1920 GR), is a stonyFlora asteroid from the inner regions of theasteroid belt, that measures approximately 11 kilometers (7 miles) in diameter. It was discovered by German astronomerKarl Reinmuth at theHeidelberg-Königstuhl State Observatory on 10 March 1920.[1] TheS-type asteroid has a shortrotation period of 3.3 hours and is likely spherical in shape. It was named "Algunde", a common German female name unrelated to the discoverer's contemporaries, that was taken from the almanacLahrer Hinkender Bote.[12]
When applying the synthetichierarchical clustering method (HCM) byNesvorný,[4] or the 1995 HCM-analysis byZappalà,[5]Algunde is a member of theFlora family (402), a giantasteroid family and the largest family of stony asteroids in the main-belt.[13]: 23 However, according to another HCM-analysis byMilani andKnežević (AstDys), it is abackground asteroid as this analysis does not recognize the Floraasteroid clan.[6]Algunde orbits the Sun in theinner asteroid belt at a distance of 2.0–2.5 AU once every 3 years and 4 months (1,224 days;semi-major axis of 2.24 AU). Its orbit has aneccentricity of 0.11 and aninclination of 4° with respect to theecliptic.[3] The body'sobservation arc begins atHeidelberg Observatory on 12 March 1920, two nights after its official discovery observation.[1]
Thisminor planet was named "Algunde", after a female name picked from theLahrer Hinkender Bote, published inLahr, southern Germany.[2] AHinkender Bote (lit. "limping messenger") was a very popularalmanac,[12] especially in thealemannic-speaking region from the late 17th throughout the early 20th century. Thecalendar section containsfeast days, the dates of important fairs andastronomical ephemerides. For 30 January, the calendar gives "Algunde" as the Germanname day analogue next toAdelgunde andMartina, the protestant and catholic entries in thecalendar of saints, likely referring to SaintAldegonde andMartina of Rome.[14]
As with 22 other asteroids – starting with913 Otila, and ending with1144 Oda – Reinmuth selected names from this calendar due to his many asteroid discoveries that he had trouble thinking of proper names. These names are not related to the discoverer's contemporaries.Lutz Schmadel, the author of theDictionary of Minor Planet Names learned about Reinmuth's source of inspiration from private communications with Dutch astronomerIngrid van Houten-Groeneveld, who worked as a young astronomer at Heidelberg.[2]
In theTholen classification,Algunde is a common stonyS-type asteroid.[3] It is also an S-type in theBus–DeMeo taxonomy and in the Tholen-like taxonomy of theSmall Solar System Objects Spectroscopic Survey (S3OS2). Only in the SMASS-like taxonomy of the S3OS2,Algunde is an Sl-subtype asteroid that transitions between the S-type and the uncommonL-type.[4][11]
In March 2007, a rotationallightcurve ofAlgunde was obtained fromphotometric observations by Slovak astronomersAdrián Galád andLeonard Kornoš atModra Observatory (118). Lightcurve analysis gave a well-definedrotation period of3.31016±0.00009 hours with a low brightness amplitude of0.14±0.01magnitude, indicative of a spherical rather than elongated shape (U=3).[9] Between 2008 and 2018, numerous follow-up observations by other astronomers confirmed the period of 3.31 hours with brightness variation maxima between 0.11 and 0.17.[10][15]
According to the survey carried out by the JapaneseAkari satellite and theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer (WISE),Algunde measures (10.70±0.36) and (11.443±0.190) kilometers in diameter and its surface has analbedo of (0.242±0.018) and (0.272±0.072), respectively.[7][8] TheCollaborative Asteroid Lightcurve Link takesPetr Pravec's revised WISE data with an albedo of 0.2055 and a diameter of 12.45 kilometers based on anabsolute magnitude of 11.86.[10] Another publication by the WISE team gives a mean-diameter of (12.440±0.073) kilometers and an albedo of (0.2348±0.0327).[10]
