_Lalage.png) Modelled shape ofLalage from itslightcurve | |
| Discovery[1] | |
|---|---|
| Discovered by | M. F. Wolf |
| Discovery site | Heidelberg Obs. |
| Discovery date | 31 March 1916 |
| Designations | |
| (822) Lalage | |
| Pronunciation | /ˈlælədʒiː/[2] |
Named after | unknownLalage[3] |
| A916 GJ · 1943 EJ1 1916 ZD | |
| Orbital characteristics[4] | |
| Epoch 31 May 2020 (JD 2459000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 103.84yr (37,929 d) |
| Aphelion | 2.6064AU |
| Perihelion | 1.9043 AU |
| 2.2554 AU | |
| Eccentricity | 0.1556 |
| 3.39 yr (1,237 d) | |
| 342.25° | |
| 0° 17m 27.6s / day | |
| Inclination | 0.7172° |
| 210.11° | |
| 247.21° | |
| Physical characteristics | |
| 3.345±0.001 h[9] | |
| 12.1[1][4] | |
822 Lalage (prov. designation:A916 GJor1916 ZD) is abackground asteroid from the inner regions of theasteroid belt. It was discovered on 31 March 1916, by astronomerMax Wolf at theHeidelberg-Königstuhl State Observatory in southwest Germany.[1] The likely highly elongated asteroid with an unclearspectral type has a shortrotation period of 3.3 hours and measures approximately 9 kilometers (5.6 miles) in diameter. Any reference to the origin of the asteroid's name is unknown.[3]
Lalage is a non-family asteroid of the main belt'sbackground population when applying thehierarchical clustering method to itsproper orbital elements.[5][6] It orbits the Sun in theinner main-belt at a distance of 1.9–2.6 AU once every 3 years and 5 months (1,237 days;semi-major axis of 2.26 AU). Its orbit has aneccentricity of 0.16 and aninclination of 1° with respect to theecliptic.[4] The body'sobservation arc begins at theBergedorf Observatory on 6 April 1916, one week after its official discovery observation atHeidelberg.[1]
Any reference of thisminor planet's name to a person or occurrence is unknown.[3]
Among the many thousands ofnamed minor planets,Lalage is one of 120 asteroids for whichno official naming citation has been published. All of these asteroids have low numbers, the first one being164 Eva. The last asteroid with a name of unknown meaning is1514 Ricouxa. They were discovered between 1876 and the 1930s, predominantly by astronomersAuguste Charlois,Johann Palisa,Max Wolf andKarl Reinmuth.[11]
In theTholen classification,Lalage has an unusual spectrum, that is closest to a darkD-type, somewhat similar to anX-type, and, to a lesser extent, a carbonaceousC-type asteroid.[4] Conversely, theSmall Solar System Objects Spectroscopic Survey (S3OS2), classifies the body an uncommonA-type in the survey's Tholen-like taxonomic variant, and as an Sl-subtype – which transitions from the stonyS-type to the uncommonL-type asteroid – in its SMASS-like variant.[6][10]
In September 1992, a rotationallightcurve ofLalage was obtained fromphotometric observations by Polish astronomerWiesław Wiśniewski. Lightcurve analysis gave a shortrotation period of3.345±0.001 hours with a high brightness variation of0.47±0.02magnitude, indicative of a non-spherical, elongated shape (U=3).[9] Since then, additional period determinations gave3.3465±0.0006 hours with an amplitude of0.58±0.01 magnitude (U=3) byDavid Higgins in October 2009,[12]3.3460±0.0005 hours with an amplitude of0.67±0.02 magnitude (U=3) byRobert Stephens in January 2014,[13] and3.346±0.001 hours with an amplitude of0.53±0.05 magnitude (U=3−) byDaniel A. Klinglesmith in February 2014.[14] A modeled lightcurves using photometric data from the BlueEye600 robotic telescope (L36) atOndřejov Observatory gave a sidereal period of3.346503±0.000002. The modelling also gave twopoles at (343.0°, −74.0°) and (133.0°, −75.0°) inecliptic coordinates (λ, β).[15]
According to the survey carried out by theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer and the JapaneseAkari satellite,Lalage measures (8.243±0.336) and (11.34±0.28) kilometers in diameter and its surface has analbedo of (0.349±0.045) and (0.187±0.010), respectively.[7][8] TheCollaborative Asteroid Lightcurve Link assumes an albedo of 0.20 and a diameter of 10.16 kilometers based on anabsolute magnitude of 12.33.[16] The WISE team also published an alternative mean-diameter of (8.868±1.502 km) with an albedo of (0.361±0.137).[6]
