| Discovery[1] | |
|---|---|
| Discovered by | P. Wild |
| Discovery site | Zimmerwald Obs. |
| Discovery date | 17 April 1968 |
| Designations | |
| (1830) Pogson | |
Named after | Norman Pogson[2] (English astronomer) |
| 1968 HA · 1926 GW 1929 EE · 1942 EC1 1945 BB · 1953 RE1 1955 FX · 1955 GE 1961 AC · 1969 QM 1971 BJ · 1972 NA1 1972 OC · 1972 OD | |
| main-belt[1][3] · (inner) Flora[4][5] · binary[5][6][7] | |
| Orbital characteristics[3] | |
| Epoch 27 April 2019 (JD 2458600.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 92.52yr (33,794 d) |
| Aphelion | 2.3117AU |
| Perihelion | 2.0652 AU |
| 2.1884 AU | |
| Eccentricity | 0.0563 |
| 3.24 yr (1,182 d) | |
| 342.96° | |
| 0° 18m 15.84s / day | |
| Inclination | 3.9540° |
| 147.45° | |
| 334.96° | |
| Knownsatellites | 1(D: 2.52 km,P: 24.24 h)[5][6][7] |
| Physical characteristics | |
| 7.710±0.669 km[8][9] 8.284±0.116 km[10] 8.35 km[11] | |
| 2.56999±0.00004 h[12] | |
| 0.2188[11] 0.2361[10] 0.274[8][9] | |
| Tholen =S[4] SMASS =S[4][5] B–V = 0.910[4] U–B = 0.500[4] | |
| 12.45[1][3] 12.61[8][10] | |
1830 Pogson, provisional designation1968 HA, is a stonyFlorian asteroid and an asynchronousbinary system from the inner regions of theasteroid belt, approximately 8 kilometers (5 miles) in diameter. It was discovered on 17 April 1968, by Swiss astronomerPaul Wild at theZimmerwald Observatory near Bern, Switzerland.[1] TheS-type asteroid has arotation period 2.6 of hours.[5] It was named for English astronomerNorman Pogson. The discovery of its 2.5-kilometer sizedcompanion was announced in May 2007.[6][7]
According to aHCM-analysis byDavid Nesvorný,Pogson is a member of theFlora family (402),[4] a giantasteroid clan and the largestfamily of stony asteroids in the asteroid belt.[5][13] It has also been grouped into theAugusta family (list) byZappalà, while forMilani andKnežević, who don't recognize the Florian clan as a family,Pogson is a non-family asteroid from the main belt'sbackground population.[14]
It orbits the Sun in theinner asteroid belt at a distance of 2.1–2.3 AU once every 3 years and 3 months (1,182 days;semi-major axis of 2.19 AU). Its orbit has aneccentricity of 0.06 and aninclination of 4° with respect to theecliptic.[3] The asteroid was first observed as1926 GW atSimeiz Observatory in April 1926. The body'sobservation arc begins with its observation as1929 EE atHeidelberg Observatory in March 1929, or 39 years prior to its official discovery observation atZimmerwald.[1]
Thisminor planet was named after English astronomerNorman Pogson (1829–1891), inventor of the modern astronomicalmagnitude scale. At theRadcliffe andMadras observatories, he discovered eight asteroids, including42 Isis and67 Asia.[2] The officialnaming citation was published by theMinor Planet Center on 15 October 1977 (M.P.C. 4236).[15] The lunar craterPogson was also named in his honor.[2]
In theTholen andSMASS classification,Pogson is a common, stonyS-type asteroid.[3]
In April 2007, a rotationallightcurve ofPogson was obtained fromphotometric observations by an international collaboration of Australian, European and American astronomers, namely,David Higgins,Petr Pravec,Peter Kušnirák,Julian Oey andDonald Pray. Lightcurve analysis gave arotation period of2.5702±0.0001 hours with a brightness variation of 0.12magnitude (U=3).[7] In the following month, a more refined period of2.56990±0.00004 hours with the same amplitude was measured by Petr Pravec (U=3).[12]
Additional period determinations were made by Melissa Dykhuis and collaborators (2.5698 h) at the Calvin College Observatory (H62) during 2008 (U=2+),[16] and byPierre Antonini (2.5699 h) and Julian Oey (2.604 h) in March 2013 (U=3-/2).[17][18]
During the photometric observation in 2007, it was also revealed, thatPogson is an asynchronousbinary system with aminor-planet moon in its orbit.[7] The mutual eclipse andoccultation events showed that the companion orbits its primary every 24.24 hours.[7][12] Based on a secondary-to-primary diameter ratio of 0.32 or larger, Johnston's archive estimates a diameter of 2.52 kilometers for the satellite, separated by 8 kilometers from its primary.[6]
According to the survey carried out by theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Pogson measures between 7.7 and 8.35 kilometers in diameter and its surface has analbedo between 0.2188 and 0.274.[8][9][10][11] TheCollaborative Asteroid Lightcurve Link adopts the result from Petr Pravec's revised WISE-data,[11] that is, an albedo of 0.2188 and a diameter of 8.35 kilometers based on anabsolute magnitude of 12.659.[5]
